Pistons for Renault 821-30 engine

[Dave M S2]

Hi everyone. I'm new to the forum & in the UK. I'm currently restoring an S2, working on the engine at the moment. Its got the 1565cc federal 821-30 engine in it. I've removed the head and noticed its fitted with the Renault flat top low compression pistons, so these are going to need replacing.

Searching on the net I've realised sourcing pattern ones isn't going to be an option. I noticed some people have had them manufactured by CPS in Italy, so I've contacted them & they'll do them for €180 a piston which is obviously expensive, but I don't have many other options at the moment.

They've requested a pattern to copy though, which I don't have. I wondered if anyone on the forum has had some manufactured themselves and has any advice, or drawings of the crown. if not an old worn, or damaged piston I could have/borrow to send them as pattern would be a real help?

Cheers

Dave

[BDA]

I suspect that there will be a good supplier in England or France, but if you can't find anything, you might try Alpine-America (http://www.alpine-america.qc.ca/). They are in Canada but they specialize in Renault and Lotus. After that, I would try Venolia (http://www.venolia.com/). They used to have pistons for just about everything. I used to get the pistons for my Spridget race car there back in the day. I have heard more recently that they still do make pistons for foreign (non US) cars. Five pistons for my Spridget costs as much as nine for a friend's Shelby GT 350 (with a 351 Cleveland engine - that probably doesn't mean much to you guys on the other side of the pond!) so they weren't cheap but they will probably be cheaper than $200 apiece.

Good luck!

[blasterdad]

I would call Richard...
http://www.banks-europa.co.uk/welcome.htm

[jbcollier]

Careful, there are 1565 pistons for wedge and hemi engines.

http://www.lotus-europa.com/data/xr1/r15.html

[Gmg31]

Please keep us updates. I've got a brand new unused one of those engines which I have just fitted to my S2.  I have no idea what it will be like yet so I'm interested in your developments

[Dave M S2]

Thanks for the responses. I will try a few more UK companies, see if they can manufacture them. I'm reluctant to get them from the states unless I have to as I've been stung heavily on import charges in the past. I've seen Wiseco list them on their site though. I happen to be travelling through Italy in May so I could pick them up from CPS myself which make that a reasonable option at the moment, plus the euro exchange rate helps. I've tried Richard @ Banks. he mentioned a group had some 1470cc pistons made recently but the company they used required a minimum of a few sets to be ordered.

Thanks for the drawing of the piston, just need some dimensions now.

Dave

[TonyWa28]

Old thread I know, but......

High compression 821-30 pistons are available from Wiseco Pistons in the U.S. – Tom Hanna 404.497.3170 ext 3170.  Had correct piston model in CAD.  4 to 5 week lead.  $175 per piston with pins and rings.  They are very nice.  Installing them shortly.

[gideon]

Also, Renault 16 shop had a batch of piston and liner sets made specifically for the Europa

https://www.facebook.com/groups/95292140870/permalink/10158553362415871/
https://www.renault16shop.com/Lotus-Europe
https://www.renault16shop.com/Lotus,Europe

[jbcollier]

Those are for a 697 engine (1470) and are 76mm in diameter.

[gideon]

They had both 76 and 77mm made.  The two links to renault16shop.com go to pages for the 76 and 77mm sets.  If you can't see the Facebook post, Geert Ehrismann said

BRAND NEW PISTON liner sets for Lotus Europe with Renault engines 697  and 821 engine. 76 and 77 mm bore.
Exact reproductions from original samples.

[jbcollier]

Cool, thanks for the correction.

[Broadside]

I guess it's just a man thing but I do love a set of shiny pistons................

[lotuseater]

Can anyone advise how much difference these higher compression pistons make? I have a 697 (1470cc) engine fitted with flat pistons.

[GavinT]

The stock Renault 697 engine with the flat top pistons was (I think) 8.6:1 compression.
The Lotus version was 10.25 compression.

As to the difference this makes . . hard to say with any precision but be aware the Lotus version also used uprated cam and valve sizes which contributed to the increased power rating.

If dealing with an unknown engine it's worth examining the valve sizes.
It could be the PO has installed an entire stock Renault 697 engine for some reason. If that's the case installing high compression pistons  is only half of the recipe.

[Triton]

Hi.   You could try  FW Thorntons & Sons.   Staffs.   01952 252892.     Stuart...