Lotus Europa Community
Lotus Europa Forums => Members Cars => Topic started by: 314159td on Tuesday,January 02, 2024, 10:23:43 PM
-
Just picked up this series 1 B, initially assuming it was a Series 2 for obvious (blinky) reasons. Originally titled in Texas as a 67 presumably for emissions and FMVSS seasons, went to New Mexico in the early 70s and last driven sometime in 78. Car #460553, and a dead ringer for a RHD to LHD conversion. We've got a poorly cut column hole, column controls on the wrong sides, wiper biased the wrong way, etc. Pinstriping is just stuck on, but I like the look. I don't think this is anything special from the factory as there's a fairly obvious seam in the front trunk from the later front end being put in.
Believe it or not, the front frame member seems to be fine. Absolutely has some cosmetic rust, but all of the typical spots near the top corners and joints are fine from a quick look with the phone camera and screwdriver prod. Original 1470 engine per the VIN plate, I purchased the car without the head installed but rebuilt. Original Solex has been replaced by a weber 28/36 DCD, which seems like it's a reasonable enough swap.
I'm curious how long these Renault engines can go without a rebuild, I figure with 5 main bearings 60k miles is a bit soon? The cylinders seem to still be in spec without ridges.
Currently, I've ripped out the original sound deadening and have discovered an unholy amount of oily mud, mostly on the passenger side. Seems like an oil change gone wrong, or someone decided to test if a fiberglass car would float like a boat. I'll need to spend another day cleaning it up with stronger degreaser, and I'm still researching the best way to sound deaden. Current plan is the standard butyl mats on the backsides of the seats and as deep as I can get into the side cavities, and then I was thinking of filling the empty space with rockwool sealed in plastic bags?
I have some specific parts questions/requests that I'll post later in the correct sub forums (flywheel cover, individual pan gaskets, front shocks) but I am most urgently trying to get ahold of formed side windows, either split as appropriate for a 1B, or the full single-piece. I'd like to get the whole car sealed up and take down the temporary carport it's currently under. I'm waiting for a reply from Banks Europa, but if anybody has a pair kicking around stateside I'd be happy to purchase and get them shipped to me in SoCal.
-
Welcome! Congrats on the car! You are going to have fun with that one!
-
:Welcome:
-
:Welcome: 314159td!!
I assume you contacted Banks via email in which case I would advise you to phone them. If you’re trying to contact the parts side (Lotus Supplies), that is a hit or miss proposition in my experience. If you’re trying to contact Richard, a phone call is the only way I’ve ever been able to reach him.
I’m looking forward to seeing more pictures and learning about your progress!
-
I used more modern insulation like this:
https://www.summitracing.com/parts/the-14620?seid=srese1&gclid=CjwKCAiAqNSsBhAvEiwAn_tmxZi21v2nk_9AbHGncB_84ceyBQBkBBl88XcILHyhEitLm88d3GR0BRoCwiwQAvD_BwE
-
As per your other post, try Kelvedon for the one piece windows. Failing that, they are not hard to make up using lexan from a hardware store.
The engines are fairly tough except for:
- piston rings breaking due to the high revs they are subjected to.
- minor coolant leaks leading to a blown head gasket
- the head being removed incorrectly -- doesn't anyone read the manual? -- and the liner base seals getting torn.
Your headless state is the most common way to find an abandoned, Renault-powered, Europa. It starts with a coolant leak. That leads to overheating and a blown head gasket/warped head. They then pull the head without reading the manual and tear the cylinder liner bottom seals. It immediately overheats again. Head off and parked. This probably a good thing as they also didn't have the head alignment tool and the distributor drive gear would have lunched itself in short order. All comes from "handy" people who don't read manuals.
All the S1s were LHD. A few 47s (S1 based) were RHD. Wiper position is correct. The single wiper actually works very well for the driver, not so great for the passenger. "Reversed" column switches, again normal. Unfortunately, the gawd-awful, hacked-up, hole for the column is not. The only thing I can think of is that a real ham-fisted person tried to remove the steering rack/column and chiselled the chassis out for more clearance. You can remove the rack and repair that.
I would go over the chassis one more time with cameras and ice picks to be sure. Then get a computer alignment to be doubly sure the chassis is straight. All good? Pump the chassis full of semi-fluid, rust inhibitor.
Hmm, sound deadening. The S1s, unlike the other Europas, have two reverse-fugle-horn chambers one either side of the passenger compartment. This makes things loud, very loud. I used sound-deadening (the good stuff) on either side of the firewall (three layers on the engine side, one inside) and, frankly, all to virtually no effect. You could fill these chambers with expanding foam (careful or you will split the body in two) but do you want to make it even MORE flammable? I don't think so.
It is what it is. Can't stand it? Get an S2. I do lots of long trips in my S1. I use aviation, noise-cancelling, headsets (with an intercom system when there's a passenger.
-
:Welcome:
314159td
Glad you found your way here!
Dakazman
-
Thanks for the welcome everyone, I have some new things to research now.
Head was removed as the "interim" owner I bought it from (had it for ~1 year) noticed a slight head gasket failure during his initial starting attempts, it ultimately needed to be skimmed ~0.004" to clean that up. Haven't done the math for how much that will raise CR yet, and we can only get 91AKI or $10/gal 100 race gas here.
Intuition and some light googling indicates that layering butyl mats might not be too beneficial, as those are to stop panels from vibrating, not truly "absorbing" the sound. Definitely some diminishing returns there. I'll probably go down the rabbit hole of researching decoupling foam and mass loaded vinyl...and heat shielding...inside the engine bay.
I don't mind fairly loud cars, but I have a good opportunity right now with things removed to try and do the best job I can should that opinion change.
-
You may also check into buying piston liner gaskets and an alignment tool for putting the head back on.
Complete gasket set also since you’ll be pulling the oil pan to remove pistons.
Maybe a set of hold down clamps for when you reassemble.
Probably easier to remove engine and gearbox.
Dakazman
-
:Welcome: and the very best of luck with your rebuild
-
You may also check into buying piston liner gaskets and an alignment tool for putting the head back on.
Complete gasket set also since you’ll be pulling the oil pan to remove pistons.
I'm going to see if I can run a test of filling up the block coolant passages with water or something inert, and leave that for a few days to see if the level drops. No signs currently point to a damaged base gasket. I'm making the alignment tools at work this week based on some numbers I've found on this forum.
-
Unless you clamp down the liners you won't get an accurate picture of leakage. Even then an actual cylinder head is probably the only really accurate way to gauge that.
-
Of course, without the liners clamped down this represents a not ideal scenario for the base gaskets but will yield some data. If they leak in this state with just 3 inches of water (0.1 PSI or so) they'll probably leak in operation. I've spent the last 6 months at work testing paper, cork rubber, and RTV gasket seals and the game for that whole thing is knocking out the easiest tests first, even if they aren't 100% representative.
Once the head is on it'll get the proper pressure decay leak test.
-
Check your cylinder protrusions as per manual. If they are off, then you're lifting the cylinders to fix it regardless.
-
I've had a few inches of water sitting at the same marked level in the water jacket for a week now, no signs of water dripping into the oil. Cylinder protrusions range from just under 5 to about 8.5 thou, sweeping in a slope from clutch to timing chain side. I think that's slightly out of book tolerance, but there isn't any evidence of the kind of failure that would cause on the old gasket. All the proper head alignment tools have been acquired...much to the disapproval of my bank account.
Just got the gas tank and heater box back from powdercoat, I really didn't want to deal with digging the heater core out ever again and these tanks seem to be impossible to find. I've made a CAD model of a mirror image tank to fit the spot on the left side, or maybe I'll just make a box to hold a NATO style gas can. Crossover pipes are annoying.
-
What's the tank like on the inside? If it's clean, good news. Lotus Supplies (Banks) used to have S1 tanks available. I bought a pair of alloy ones for mine. The "crossover" pipe is a short length of 5/16"/8mm fuel line. Not a big deal.
-
Inside is totally clean with the original coating(paint?) to the midway mark, then very light rust above that, slightly heavier in the neck. This tank is unreasonably thick and heavy for a Chapman design. Outside bottom wasn't doing great so that justified the blast and powdercoat. Sender works fine on the bench and in the car so that can stay for now.
For the crossover, I don't like having to open both caps to fuel, so I also run an air line higher up on the tanks and that's now double the work. I have a very cheap station a block from my house so capacity is only a problem on road trips, which I already carry jerry cans for to game the different tax rates between surrounding states. It's a "when I gut this entire car if I still have it in a decade" thing, but I am happy to have the tank logged in CAD regardless.
Looks like a rainy (and humid) weekend, so I might have the head on and running on starter fluid soon. Gotta re-read that manual section to make sure nothing is missing. I wish we had something like the Spitfire workshop manual, which is literally more pictures and diagrams than text.
I also had an electronic ignition module come in, $26 on Aliexpress and the same manufacturer as my equally cheap one on the Spitfire engine. Will make a post on how to find and install those cheap units after confirming this one works. PerTronix is highway robbery for their component cost.
-
Get a Renault 17 factory manual (or R16 depending on what you have). It covers the engines and transaxles in great depth with every step carefully illustrated.
-
:Welcome:
Welcome!
it's great to see another S1!
Mark
-
Went and dropped the pan today, noticed a little bit of water right at the start of draining it. Figured that might be condensation from having the head off but curiosity got the better of me to I refilled the water jacket. No drips or change in water level over several hours, like before. Then I got a sheet of closed cell foam and a piece of aluminum, held those down to "seal" up the water jacket, and used a 10 PSI regulated air nozzle to blow into the block drain port.
Steady stream of drips from the forwardmost cylinder ::)
So, looks like this engine (and transmission) is coming out anyway.
I'm planning to get:
- liner, ring, and piston set: https://www.renault16shop.com/Piston-and-liner-set-Lotus-Europe,-diameter-82,50,-76-mm
- liner seals: https://www.renault16shop.com/7700508016,7700508017,7700509556
- standard size main bearings https://www.renault16shop.com/7701348413,0996105000,0996049000
- standard size big end bearings
- crankshaft thrust washers
- full gasket set, though I already have some/most https://www.renault16shop.com/7701450505
- oil pump impeller dohicky (the part that wears out), pending measurement of mine. https://www.renault16shop.com/0996053300
also need a new screen/just the pickup tube, not finding that except included with the whole cast pump housing. - engine and transmission mounts, no idea who has those at a fair price. My understanding is that some sellers sell Anglia mounts, which have issues.
- rear suspension bushings if they exist
- transmission gaskets and seals, will place another order for internal transmission bits after cracking it open
- clutch disc, pressure plate, throwout bearing https://www.renault16shop.com/7700502795-7700586960-7701348537
- clutch cover (mine is missing, would like to buy this used) https://www.renault16shop.com/7700526333,7700510333
Unsure if I would need to replace the timing sprockets, guessing not, but definitely a new chain and tensioner. Renault 16 shop has some wack prices, might be cheaper to get the whole set with sprockets anyway.
This list is mostly for myself, but if anybody thinks I'm missing or don't need something, let me know.
In better news the original radiator is proofed to 10 PSI and the heater core has a leak...in a super easy spot on one of the tanks. I also think that somebody has messed with my axles, as one is of a noticeably larger diameter than the other, but I'm going to ignore that for now.
-
Your link for the pistons is for the 697 (1470cc) engine.
Given you're in California, I suspect you want pistons for a Type 65, 821 engine (1565cc)?
Best not to buy the bearings & thrust washers until you've measured the crank - same thinking for the timing sprockets.
Yes, I don't think I've seen the oil pump screen as a separate part.
Bushings and mounts etc. should be available from one of the US usual suspects.
Same for the clutch but I'll let someone else chime in because I've lost track of what's going on with the throwout bearing.
-
Your link for the pistons is for the 697 (1470cc) engine.
Given you're in California, I suspect you want pistons for a Type 65, 821 engine (1565cc)?
Nope, for better or worse. Series 1B with the 1470 engine (697-4), grey market import to Texas before they were officially sold here.
-
+1 on stripping and carefully examining what you have before ordering. If the crank bearings look fine, then just pull the pistons and liners. Maybe only a hone and new rings is all you require, other than gaskets of course.
Same with the crank shims. Measure your end play. If it’s good, no need for new parts.
-
I pulled the main caps off one at a time, seems like the crank journals are okay enough but bearings are a bit icky, might have been run with contaminated oil. Didn't check the big end bearings but assuming the same story there.
My experience with crank thrust washers is on the little Triumph engines, which chew through quickly and blow up if you forget to change them. I figure not so much here?
Is that something I can get a sense of with the engine installed and having someone press the clutch? Tried to shove the crank back and forth and didn't notice anything, but I have a dial indicator and magnet base I can use for that.
I'd rather not have an un-rollable car for too long, but I should probably just accept it and figure out how to get the back end on a furniture dolly.
Honestly didn't even think to measure the bores, just assumed they were okay enough to send it but not worth replacing gaskets and keeping the old liners. Almost completely smooth.
-
People have built contraptions to hold the half shafts in the right place to let the car be rollable without an engine, if that’s a holdup.
-
Dial gauge on a crank web and two screwdrivers to push the crank back and forth. Specs in manual. Triumph engines have heavy clutches and only half thrusts. They can wear quickly. Renault engines have full thrusts.
-
Nope, for better or worse. Series 1B with the 1470 engine (697-4), grey market import to Texas before they were officially sold here.
Oh, OK.
Just one thing to add; piston & liner sets usually include a set of 'paper' ring seals for the sleeves.
Might be worth checking with R16Shop to be sure.
-
So, I did some measuring of things and started getting concerned, eventually making this spreadsheet. This post slightly references my posts in this thread: https://www.lotuseuropa.org/LotusForum/index.php?topic=3575.15
Boxed values are directly measured/not calculated. I CC'd one chamber of the head about a hour ago, will do all of them eventually and double check.
Red values are pulled from here:http://www.syer.net/donor_cars.htm (http://www.syer.net/donor_cars.htm)
Notably my head is thinner than the mentioned minimum thickness, it was skimmed by the interim owner who identified the warped head and hasn't been reinstalled. I have some minor concerns about valve interference if anybody has a head thickness number for when that becomes a problem.
Anyway...standard raised pistons are out of the question unless I'm running race gas. I'm pretty sure 13:1 is around the highest production cars got on carbs and mechanical ignition. I have no intention of using anything other than currently available pump gas, which tops out at 91 AKI here (at sea level).
9.2:1 with flat-top pistons seems reasonable? My Corvair is 9.25:1 and timed per factory specs but occasionally pings in hotter months, though you can't really compare engines like that. The odometer is about to roll over and it might have hot spots or other issues so ¯\_(ツ)_/¯
I could just slap standard renault pistons in and run on 89 or 91 AKI gas, or I could buy the raised top pistons and machine them down *some amount* to achieve a specific CR between 9 and 13:1, possibly even the original 10.25:1 though I feel like that would ping tremendously?
Does anybody have experience running Lotus stock-spec 10.25:1 1470 engines on 91 AKI gas? Preferably with the stock cam and maybe even with a skimmed head? Any info on the pinging limit is useful.
AKI is just the standard US octane rating if you're unfamiliar, before someone mentions how much higher theirs is (in MON or RON)
-
Could you explain your calculations? What is “head volume” as opposed to “combustion chamber volume”? If your calcs have the flat-tops at 9.2, I can’t see how the raised tops would give 13s.
Some engines are prone to knocking and pre-ignition. The Renault Cleon engines are not. You can run high CRs. Maybe not 13+ though. I’m running into the 11s quite happily, albeit with a crossflow.
-
Head volume is the volume of one chamber of the head, as you would get from CC'ing it. Piece of polycarbonate with a hole and a burette and such.
Combustion volume is "Volume at top dead center", which has to add in the additional space created by the head gasket, and subtract any volume for a raised piston. Of course, that assumes that the top edge of the piston exactly meets the bottom of the head gasket.
Flat top to raised top does give an increase from 7.6:1 to 10.25:1 (if I'm understanding things correctly), and those have a non-linear impact on CR so 13.7 doesn't seem absurd to me.
I used the published Renault and Lotus engine figures to calculate the approximate volume of that raised piston section (~16cc, feels correct) and apply that to my engine, in addition to just normally calculating the current compression ratio with flat top pistons. My head is skimmed about a millimeter, and seems to have ~17cc smaller combustion chambers than stock. If anybody has CC'd a stock head I can sanity check that 56cc number.
Here's a direct link if anybody wants to poke around the math: https://docs.google.com/spreadsheets/d/1xGBd_ZZnM73jezMyqmUdjQCRs1Sq9V1fw_AyUOi6bPo/edit?usp=sharing (https://docs.google.com/spreadsheets/d/1xGBd_ZZnM73jezMyqmUdjQCRs1Sq9V1fw_AyUOi6bPo/edit?usp=sharing)
I had a couple Otto cycle engine lab reports in college and I'm reasonably confident in the numbers, but there could also be aspects of the Renault engine I'm missing. If the pistons *don't* just about reach the bottom of the head gasket that would throw the numbers off slightly. Going to take more measurements to fully validate over the next week.
-
I'm not understanding the term "Boxed values".
Looking at your spreadsheet, there seems to be marked differences in combustion chamber volumes (head volume).
If you've measured 38.50cc and the stock head is supposed to be 55.67cc, something doesn't seem right to me.
Consider another angle:
The volume contained in a cylinder 76mm dia. x 1.00mm high is 4.54cc.
Given 1.00mm has been skimmed from the head, that's a 4.54cc* reduction in chamber volume.
*Given the combustion chamber is not a full cylindrical shape, the figure would be less than 4.54cc.
Am I missing something?
Some time ago there was discussion about figuring out these volumes. JB had the best and simplest idea IMHO, which, if I recall, amounted to installing the head & gasket, sealing everything with Vaseline, set to TDC and do the burette routine via the spark plug hole. This method should also avoid error stack-up.
Another thought - perhaps a custom thicker gasket might save the day?
I think Richard Mann has thin ones so he might have thicker ones as well. Salv Sacco would be another option.
-
Consider another angle:
The volume contained in a cylinder 76mm dia. x 1.00mm high is 4.54cc.
Given 1.00mm has been skimmed from the head, that's a 4.54cc* reduction in chamber volume.
*Given the combustion chamber is not a full cylindrical shape, the figure would be less than 4.54cc.
Am I missing something?
"boxed" meaning really more like outlined.
Yep, the guys at work were digging into that. We figure there must be something off with one of those assumptions or the input values as the math itself checks out. Someone got smart and suggested just finding a measured value for an untouched head's volume, because my calculation for that has several potential sources of error (we're thinking a rounded/wrong advertised compression ratio). Just take the delta of the stock head volume versus mine, and machine that amount off of a raised piston :headbanger:
-
I’ve been meaning to go through your math but haven’t had the time yet. If a flat top piston is 9.x, there’s no way the raised pistons are bumping it to 13.x. There’s just not that much extra material.
-
My math spits out just under 1 cubic inch of material in the raised section of the piston, and that feels right based on the pictures I've seen?
Haven't seen one IRL so that could be off, and probably is if any of the published specs are a few % off.
-
Interesting discussion on CR. Static is one thing, dynamic another. Intake valve closing is the big determining factor on the real compression. Cam timing plays a huge part, so you can get into trouble if you want a streetable engine on pump gas, or even a race engine on racing gas. There are online calculators that can help you out on determine the running compression.
Short story. Friend bought very expensive Kirkham replica Cobra with a new, but never run 302. We had all the spec’s and parts numbers, except the cam spec card. Also did not know where the cam to crank timing was set. Stored for years, but completed and supposedly ready to go. After initial prep, could not get it to run at all. Not the first time around the block for either of us with these engines. On tear down, come to find out the dynamic compression was about 6.25 to 1. So, wrong cam, cam timed wrong, retarded to apparently run on pump gas? The point is the advertised piston static compression was 10.5 with the heads advertised cc’ column. That advertised CR really meant nothing with this cams timing. New cam, more advance, dynamic now at 8.7 to 1. Runs nice on pump gas.
-
OK, I think I've figured it out, so correct me if wrong.
I believe the error is in column E where the "Raised piston volume (cc)" is already accounted for in the "Head Volume (cc)".
Also, "Head Gasket Volume (cc)" wasn't included in the calculations for columns B & C, and when you do, the compression ratio seems to come out wrong.
Columns B & C also appear to use different formulae to calculate "Combustion volume (cc)" so I didn't go further down that path.
As a cross check, here's my effort.
My assumptions are contained in column B where I just tweak the "Head Volume (cc)" until I get the "Calculated compression ratio" right.
This establishes the "Head Volume (cc)" which is carried across as a fixed value.
Column C is tweaked similarly via "Raised piston volume (cc)" until "Calculated compression ratio" looks right.
This establishes the "Raised piston volume (cc)" as a fixed value.
Columns D and E are then extrapolated and I've included the "Head Skim allowance (cc)" mentioned in a previous post. I took a stab in the dark and assumed 3.5cc as an estimate of the material removed.
Does that look right?
Hoping this link works.
https://docs.google.com/spreadsheets/d/1c3XQoc8EcwDdMsnPR-BS5--745BCabZZrsURfPMtvwI/edit?usp=sharing
-
Also, "Head Gasket Volume (cc)" wasn't included in the calculations for columns B & C, and when you do, the compression ratio seems to come out wrong.
Columns B & C also appear to use different formulae to calculate "Combustion volume (cc)" so I didn't go further down that path.
https://docs.google.com/spreadsheets/d/1c3XQoc8EcwDdMsnPR-BS5--745BCabZZrsURfPMtvwI/edit?usp=sharing
This was the main issue, somehow it's always the fancy formulas that are right but the simple addition gets messed up. I should have caught that head volume and combustion volume were equal in column B sooner. When I fix that, I get a stock head volume of 49.5cc and the raised piston volume stays the same at ~16cc, as you've reached manually by iteration. Other values of the sheet remain unaffected, as that stock head volume is just for sanity checking once the raised piston volume is calculated . I added a tab to my sheet with the original head volume formula corrected.
The issue is that my head chambers are ~39cc, as I've measured directly. That is now a removal of 11cc from the calculated factory value, which is closer to the 4.54cc estimated value you proposed earlier (in the incorrect sheet, it was 17cc off). When I make a copy of your sheet and adjust the head volume to be what I've measured, we have the same values.
Another possibility to explain that misalignment is that the published stock head thickness may be incorrect? Or at least for my head? That would tidy all of this up nicely if that were the case.
Let me know if I've misinterpreted something there, but the 38.5cc is a fixed value. The sanity checking is much appreciated!
Sidenote as it didn't create any issues here: the difference in formulas for combustion volume between B and C was a remnant of working backwards a different way, but it happened to not matter as the subtracted value was 0. That's just the inverted static compression ratio.
Further sidenote: I'm basically ignoring dynamic CR here, as I intend to keep the stock camshaft. Matching static CR should keep everything in order for this particular rebuild.
If anybody has a stock 697-04 head laying around and could cc it that would be great! I'd be willing to send you the supplies for it. Might make a separate thread for that for visibility.
-
Alrighty, let's accept the 38.50cc chamber volume because it's an empirical measurement.
Without argument to the contrary, we also need to provisionally consider "Head Volume (cc)" of 49.50cc because it results in the published compression ratio.
Obviously those two numbers are at odds.
There's 11.00cc missing.
If we accept the head skim accounts for ~3.50cc, we still need to find ~7.50cc thus:
38.50 + 3.50 = 42.00cc
Initially, I couldn't convince myself the space above the piston would account for 7.50cc because the raised plateau of the Lotus pistons is quite broad.
For that to make sense, the top of the piston plateau would need to be ~2.00mm below the liner height, but perhaps that is the case.
Need more data.
I reckon the next step is to discover the total volume via JB's method.
Alternatively, use the Lotus piston/liner kit from R-16Shop and get a 2.7mm custom head gasket. In saying that, I'm not sure how the rubber perimeter seal around the camshaft might handle a thicker gasket.
Lots of basic caveats to be aware of around all this, too.
If the head has been skimmed, I'd assume it was overheated at some point. Given it also has low compression pistons, I'd wonder why. Was that part of the overheating issue or something else entirely? What if they also took a lick off the block and decked the liners to suit?
As I say, lots of caveats with an unknown engine - measure everything.
-
More measurements on the way! As I don't care about liner seals I'm going to rotate the engine (by rolling the car, not turning the cam pulley) and verify/measure that the pistons reach the top of the liner. That's one of the larger assumptions I haven't seen confirmed yet. Most engines do that...not all.
The low compression pistons are still puzzling; it means someone tore into this engine pretty early in its life, or it left the factory like that for some reason. The person that had the head skimmed said it was only about 4-5 thou removed, so maybe another person before that removed the bulk of the material? Perhaps they could only get low compression pistons and chose to raise the CR via a head skim?
I'm pretty set on just getting the Lotus pistons and liners, and machining some off the top to keep CRs in line. I hate sending stuff to the machine shop but that's an easy job on the lathe at work. Cheaper and easier than figuring out a custom gasket.
-
I would be looking for a standard head.
Skimmed that heavily brings the entire valve train into question as well.
I think I have a "scrap" head here, that might actually be repairable with some welding.
Had a blown gasket between two cylinders and got notched.
I will look and see if it is still around.
Yours for shipping cost if I find it and you want it.
-
Eh, ~1mm is usually well within the limits on OHV engines and it seems like the adjusters have it in them. The pushrod geometry is a bit more aggressive with the cam this high in the block but I'll sketch up the geometry at a later point and determine if the rocker pedestals need to be shimmed and/or shorter pushrods made. That're really not much of a skim, compared to the 3-4mm on contemporary race engines that definitely do need need them.
Head is already built up with ground seats and valves, and passes the compressed air leak check, so it's going to make its way onto an engine eventually.
-
The minimum head thickness is not to do with CR but with position of the cam lobe on the follower. It will still run, no problem, but cam/follower wear will be higher. This is not a factor in frequently overhauled racing engines and I have seen a couple of successful race engines with aggressively shaved heads. However, shortened cam/follower life may not be what you want in a street engine.
Renault engines are very strong but they do not like to be overheated. Combine that with the fact the cooling system requires careful bleeding, it was not unusual for a careless owner to toast a head gasket or even engine. This is why most Europa projects are discovered headless and/or with replacement engines.
Please, please do not machine your new pistons until you get a correct CR calculation. It is possible to weld and machine piston crowns but it ain’t cheap!
-
As an old (85) engine engineer, I am very much enjoying this discussion.
I am amusing myself by working through a cross flow engine that had some debris go through it.
You will find it interesting to pull the liners out - mine had at least a 1/4" of rust all over the water side. The inside was glazed with small scratches but cleaned up with a hone and is within usable tolerances.
I won't get into the details but can add comments re potential parts suppliers.
I placed an order with the Renault shop about 2 weeks ago. They accepted the order and asked me to wait until they send an invoice before paying. I am still waiting, despite a follow up email.
Another potential good parts supplier is der franzose (www.franzose.de) in Germany.
I placed an order with them on a Sunday night several weeks ago, called them the next day with a question about the order and it had already been dispatched. That's the good news! They ship with DHL and it was sent by sea. No projected delivery date is yet available from the DHL site.
Their prices are slightly better than the Renault Shop based on my shopping list.
I would be interested to know where you located the special head tools.
Thanks and keep up the good work.
Grant
-
Engine is out after building a gantry frame from definitely not untreated 4x4s, surprisingly easy with the harbor freight load leveler. I might make a post about this setup as it does pretty well in place of the proper lift sling tool. Was very surprised that the engine (w/o head) and transaxle balance like this.
-
I think I found the weird engine discrepancy!
The place I was pulling data from, Dave's page here (http://www.syer.net/donor_cars.htm) uses a 697-02 engine to compare to the Lotus tuned 697-04, not the -01 found in the standard R16L. The -02 must be the low compression version of the engine for certain export markets, as it has a 7.6:1 compression ratio rather than the 8.6:1.
Anyway, changing that on the sheet, I get a 3.66 cc delta due to the head skim, right on what Gavin was getting at. Leaving the pistons at their full crown would give 11.1:1 CR, which is very reasonable but I think it'll take them down a hair for our piddly 91 AKI.
Thanks all for poking around!
The DMV has attempted to charge me $960 in back fees on the parallel project, so the Europa is back in focus while I wait two months (or more!) for them to read their own handbook.
-
The amazing thing is that you were prepared to machine your pistons based on figures pulled off the internet.
-
I think I found the weird engine discrepancy!
The place I was pulling data from, Dave's page here (http://www.syer.net/donor_cars.htm) uses a 697-02 engine to compare to the Lotus tuned 697-04, not the -01 found in the standard R16L. The -02 must be the low compression version of the engine for certain export markets, as it has a 7.6:1 compression ratio rather than the 8.6:1.
Ah, right . . I should have twigged.
The early Renault16's are probably better referred to by their Vehicle Type which is R1150 and came with either the 697-01 (High Compression) 697-02 (Low Compression).
The language Renault used was for markets with "poor fuel". There's many variations on the R1150 theme and I'm not sure anyone has it all figured out.
Here in Oz, we had a Renault assembly line for the CKD cars and our versions were fitted with modified suspension for our "poor roads". Back then this was a common practice for imported cars which sometimes suffered badly in our outback.
-
Starting to gut the engine...further evidence that somebody was in here with no idea what they were doing. Weirdly, I wasn't getting an obvious drip from this one. The power of corrosion as a sealing mechanism ::)
Main bearing caps are all sorts of messed up as well, the number stamps are in a backwards order.
-
#1 cylinder is by the flywheel.
-
I'm aware, though they're messed up in a way that is agnostic to the correct piston numbering scheme. Rod cap order is correct, main caps seem backwards, plus something else maybe.
The manual implies the rods come marked, and the main bearing caps must be marked by the reader, so maybe the latter were simply marked incorrectly at some point? But the stamp font is identical on everything, so that seems unlikely.
I've recorded their current orientation regardless, hopefully that hasn't caused issues. At first glance, the crank journals appear unharmed.
-
Back to compression ratio discussions...I happened across something that gives me an idea. While thicker head gaskets don't seem to be offered (I might not be French enough to find them), this site sells a 0.5mm "Cylinder head copper shim" (https://www.arnaudventouxpieces.com/en/cylinder-head-copper-shim-05mm-thick-1600cc-a110-r12-g-2144.html) for the same engine family, directed at the A110 and R12.
Assuming nothing lost in translation, that implies someone has figured out how to make a simple head shim work with the rubber oil sealing gasket. Maybe the answer is just RTV silicone, it seems solvable regardless with low crankcase pressure.
Given the more complex interface on the block side, I think I would put the normal head gasket on the block and a shim on top of that, with the standard copper spray some people seem to swear by.
I would need a shim of ~0.8 to 1.1mm, slightly thicker than what's usually offered (0.020 in or 0.5mm seems to be the standard, including some newer engines).
Lotus's shop manual specifies a maximum of 0.3mm removal, stricter than I've seen elsewhere, implying their camshaft modifications further eat into the margin. That's what sent me on this investigation while examining camshaft geometry and my 1.07mm shaved head.
Manufacturing isn't an issue, but I need to figure out if either steel or copper makes more sense. I feel like annealed copper is a "safer" choice for sealing, and there aren't any super close bore spacings that sometimes blow out weak gaskets, like on the classic Minis. Most concerned about water leaks honestly.
I have some backup ideas for a custom, thicker rubber oil seal as well, or maybe extend the shim to increase the thickness of everything on the head, not just the head gasket area.
Thoughts? Murmurs of other people doing this? I know some manufacturers had an OEM shim kit like this in the 60s to lower compression, but Renault seems to have addressed that though dedicated engine variants, so I don't expect to find an example in their manuals.
It seems like this solves more problems than machining down the pistons, and is fully reversible without removing the engine in case it fails. Happy to put money in someone's pocket for a head and then rebuilding it if I absolutely have to (I see you Richard48Y, and those alloy rims).
If I just slapped the head on with domed pistons, it would be 11.1 CR, which is probably fine going by JB's comment earlier in the topic, but if I wore a cam lobe flat...the engine is coming out, or a hole saw is going into the firewall.
-
I think I finally a set of alloy wheels that look right, going for a 70s/80s retrofuture aesthetic. Came off a Spitfire, they should sit about 1/2" further out than the originals - similar to the later Europa alloy wheels. Apparently made locally, which is always neat.
-
Those are nice!
-
I have two of those.
Had four until a wheel restoration shop lost two.