Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: califkid_66 on Tuesday,October 22, 2024, 11:57:05 AM
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I read that the oil drain for the distributor is nessesary for lubrication. the oil passage was milled of my cross flow it is already assembled but if it’s nessesary I would remove the head and make another oil passage
any info on this would help
The first picture is how mine looks and second is how it is normally
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Yes I would remove and cut a channel.
However I’m only a novice on these engines. I used that passage to prime the oil pump so I would think it as necessary. It also lubes the shaft .
Dakazman
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That’s what I was thinking I just want to make sure everything is perfect not to have any surprises
It was already assembled so I’m going to have to get another head gasket I don’t think I can reuse the new one I put in
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Califkid , never reuse a head gasket.
I agree, better safe than sorry. When you remove the head remember to bolt down the liners.
My other concern would be your valve clearances to pistons and the limit on the head itself.
Dakazman
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I did turn the engine over when I adjusted the valves everything seemed ok
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The passage supplies oil directly to the drive gears so it is a good idea.
You NEED to clay your combustion chamber to make sure your valves are not too close. I use modelling clay from an arts and craft store. You are looking for 60 thou minimum between the valve head and the piston.
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Looking at the pics, the head seems to have had a fair lick of material removed - maybe 2mm?
To add to what others have said, I'd also check the dizzy has sufficient end clearance to the drive gear.
You might need to shim the dizzy body.
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The picture is not of my head just wanted to show what I was talking about
My base is from a fuego turbo pistons are not domed there should be enough clearance
I would like to order a 123 ignition but the one like JB that can fit on the wedge and on the crossflow but can’t fin any link to a company that as them i do have to shim the distributor I figured about .050 picture of my head and block below
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Hmmm... can't help with the 123 ignition, but I'm confused.
The top pic seems to show a crossflow head with material removed from the squish area. This is a mod normally required for the use of the highly domed R12G pistons.
The lower pic seems to show Lotus pistons from a wedge head but seemingly with fairly significant valve reliefs, particularly so on the exhaust side which seems odd.
Have you calculated the compression ratio?
What am I missing?
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I did try to calculate the compression ratio a while ago
9.16:1 not sure if I did it right
the thickness of a stock head should be 3.681 mine is 3.625 so it was shaved.056
I was told the pistons were 9:1 my guess is the head as been shaved a lot witch brought up the compression ratio a bit to high so some material was removed from the combustion chamber to lower it back to where it needs to be
Also i noticed the head gasket was for 77 instead of 79 witch lead to a little confusion as to what size engine I had
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123 ignition .... https://123ignitionusa.com/renault-special-order-only/
Ed is pretty helpful!
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Hmmm...
The top pic seems to show a crossflow head with material removed from the squish area. This is a mod normally required for the use of the highly domed R12G pistons.
The lower pic seems to show Lotus pistons from a wedge head but seemingly with fairly significant valve reliefs, particularly so on the exhaust side which seems odd.
Good eye Gavin on the exhaust side of the piston, usually the intakes are larger.
Turbo,
Thanks for the link to 123. I'm biting my tongue on when to purchase them, or even what to ask for as per dimensions. Califkid knew his dimensions and the dimensions of his gasket. So, thank you all for your input here. :trophy:
Dakazman
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Thanks for the link Turboforce I want to get the 123 ignition with the extension so I can use it on both of my Renault engines
Dakazman when ordering the 123 I’m not sure but they are only two sizes you can order the one for the wedge is shorter or you can get the one for the crossflow witch is longer or the wedge one with a removable extension in my case I know my head was shaved a lot so what I will do is shim .056 under the distributor that should put it at the right height
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Wow 0.056" seems pretty aggressive. Mine wedge head was shaved closer to 0.040" and I'm going to do a copper shim for that, mostly because I don't want to deal with any complications from the different valvetrain geometry. Already have a design done just sitting on my hands about where to place the order.
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Shaving the head by a large amount isn't necessarily a problem in and of itself. It's the flow-on effects that need to be considered.
Foremost and obviously, intrusion into an oil or coolant passage is an issue as might be the thinning of the available material.
Currently, an oil channel and a dizzy height issue has been observed.
There's also the possibility that the rocker geometry might need height correction via shimming. This is a common practice for competition engines.
Given the head is effectively lowered and the cam has remained stationary, an issue might be found in that the cam will now have inevitably altered timing. This is commonly addressed via an adjustable cam sprocket.
It might also be that the tappets now need to be recessed into their bores so as to recover stock clearances to the cam lobes.
And the use of Lotus 821 pistons might not be automatically detrimental overall, but you'd need to get the unit on an engine dyno and be able to compare it to a known spec before anyone could say anything significant one way or another - not terribly practical for most of us.
The stock Lotus CR was 10.25:1 if I recall.
That said, I'd also want to know if the valve reliefs haven't come too close to the top ring. Visually, the valve reliefs look to be significant so I wonder about the extent of cam lift.
Lots of things need to be measured & checked when radically departing from the safety of a factory spec. - you pays your money and takes your chances but none of this is the end of the world IMHO.
My $0.02 worth, anyway.
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At first, 123 didn’t offer a distributor for the crossflow. Another French company modified the wedge offering by fitting an extension piece to the shaft. Now that 123 sells their own crossflow version, the company no longer does this mod.
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At first, 123 didn’t offer a distributor for the crossflow. Another French company modified the wedge offering by fitting an extension piece to the shaft. Now that 123 sells their own crossflow version, the company no longer does this mod.
Thanks JB,
That statement saves me a bit of time, in trying to cross utilize the distributor between the two.
Dakazman