interesting 4.0

[Engineer1949]

been doing some work on a very nice 4.0ltr chim one job new cam etc when stripping noticed double valve springs then very nicely ported heads etc. so fully expecting it to be an hc but standard cam with hivo chain it was still going very well lots of grunt coming in around 3500rpm but car has full history no mention of upgrades and 50,000 roughly on the clock any ideas


john

[Pupp]

What year John? Some early ones had head work done

[ClassicChimaera]

Dom will have a build sheet for that John, and yes I think the earlier cars had more (in house) work done on the heads.
Seems by 95-6 he was bored with RV8 and rather more busy with the AJP Speed6 engines

[Engineer1949]

its not very early P reg will give dom a ring good call


john

[Sardonicus]

Not seen a standard (not been got at) 4.0 yet in a Griff or Chim that dont have double VS's the heads definitely not stock though on this car in question

[caduceus]

Sounds similar to my 4.5. Whilst stripping down, I found out it had 'medium big valves' and someone had been in there with a flap wheel and done some porting under the valve seats.
I showed it to a guy who used to work for Hart F1 who just does head work for LM cars, Astons, etc now and he said it wasn't a bad job. He also showed me how to finish off the job. All for a tin of biscuits

[l6rth]

Does Dom have a build sheet for every car? I have a p redg 4.0 chimaera that I'd be interested in find out about as it does seem quick to my previous 400.

[Brithunter]

So it would seem the desire to have an early Chimaera might just be a good one. Would this extra care work also be found on the 4.3's?

[Engineer1949]

seems likely i rebuilt one a couple of years ago turned out to be a big valve 4.3 and once sorted was very nice


john

[V8Mad]

Interesting thread. My '93 4ltr has similar characteristics, 3500 rpm is when things start to kick off. Quite even torque throughout rpm range, but hp is on constant and even climb like a ski slope from idle until peak power at 5450 rpm. I assumed it had been mapped as other owners power curves show more lower end grunt. Decided to remove ecu cover today...no sign of aftermarket chip, just '4.0' in black marker...

[Brithunter]

Engineer1949 said:

seems likely i rebuilt one a couple of years ago turned out to be a big valve 4.3 and once sorted was very nice


john

Interesting ........................................ Thank you for the info!

[OleVix]

All the 4.3s are ported/worked on, not just the BVs

Also my LHD Griff 400 cat from 93 went remarkably well, better than my 97 400 chim