ERC 0216 part number cylinder heads

chrisbowler · Post by **chrisbowler** » Sat Mar 28, 2015 10:03 pm

Some help please. I have just bought a pair of cylinder heads described as TVR Chimera cylinder heads with a part number ERC ERC0216 with I though were SD1 heads. They are 14 bolt heads

The heads are different - not a pair ( different casting numbers and have been described as Stage 2. Did TVR Chimera 400/450 get fitted with 14 bolt heads and how can I tell they are Stage 2? The exhaust valves are not magnetic (Stainless steel?) but the inlet valves are magnetic. For the money, I feel I may have bought earlier heads that have been dressed up.

CB

mgbv8 · Post by **mgbv8** » Sat Mar 28, 2015 11:08 pm

See here

http://www.v8forum.co.uk/forum/viewtopic.php?t=133

chrisbowler · Post by **chrisbowler** » Sat Mar 28, 2015 11:51 pm

So as a head to upgrade to stage 2 mods these appear to be ok. My engine is a late 4.6 - just wanted to be sure older heads were not a retro step. Does it make any difference that the castings are slightly different between the pair

CB

sidecar · Post by **sidecar** » Sun Mar 29, 2015 7:59 am

The older heads have larger chambers and would be a retro step when fitted to a 4.6 engine unless you have them skimmed in order to get a decent CR. I run stage III heads (14 bolt) on my 4.6, I only run 10 Arp studs in the heads. The block is not drilled for the outer bolts and even if it was I would not use them!

chrisbowler · Post by **chrisbowler** » Sun Mar 29, 2015 11:15 am

Thanks.

I have a 4.6 that has had new 4.0 HC Pistons fitted by J EDevelopments. John has said I should have about 10:1 CR.

I bought these heads described as Stage 2 TVR heads but do not know how much has been skimmed off. I can work out from STD measurements.

Sadly I made the mistake of buying what I thought were reconditioned stage 2 heads but as I am not an expert, can't confirm exactly what I have got. Hence the questions about the older head castings.

Chris

sidecar · Post by **sidecar** » Sun Mar 29, 2015 2:10 pm

The 4.0 pistons will make a difference, it might be possible to work it all out but if it was my engine I'd do it the 'old school' method....basically I'd burette the pistons at TDC, I'd do the heads then work out the CR. You can calulate the volume of the head gaskets which will depend on their thickness.