Main British Car:
Rover V8 heads max skimming
Posted by: Mimic08
Date: April 19, 2019 09:44AM
I am french TVR chimaera 94' owner with a stock V8 Rover 4.0 (which is a 3.9 in fact ) with 14 CUx Lucas software. Time is gone to change chain. During this mecanical operation, I want to overhaul my engine in goal to have a performance road use car (not a race car).
I bought a MC1 camshaft sold by a english manufacturer : V8development (I think spec is near a crower 50232).
I setup shorter inlet trumpet. Inlet pipe are porting and overhaul (exhaust too)
I bought a good used Stage3 14 bolts ERC 0216 heads (Big valve 43mm inlet et 39mm exhaust) . I was astonished to find late 10 bolts heads on my engine (HRC 2479): my cylinder block is a genuine 14 bolts.
My idea is to have a good CR ratio and have a good reliability: 9,35 < CR <10 (like late TVR Rover 4.3/5.0).
I measured yesterday my volume chamber :
- ERC 0216 : 34cc
- Stock HRC 2479: 32/33c (not 28 like announced officialy)
More questions to reach my goal:
- which is max thickness could I skim on my head
- real piston volume from 3.9 rover ( 21cc?)
- best head gaskets to use ( thin metal 0.4mm but knwon unreliable, elring composite 1.3 mm 10 bolts, Cometic head option 0.027/0.03/0.04 " thickness)
I do'nt find information on french website . Your help is very welcome
Main British Car:
Morris Minor Rover V8
Re: Rover V8 heads max skimming
Posted by: minorv8
Date: April 26, 2019 01:15AM
Factory 10 bolt heads with nominal 28 cc chamber were supposedly the same as earlier csatings, only skimmed to achieve a smaller chamber volume. Also the valves were machined deeper into the seats. I had a pair of 28 cc heads and they were pretty close to advertised 28 cc. The only big issues are: does your head still have enough material and if your manifold will fit if you skim excessively.
Piston volumes differ from model to model, best to measure them.
I have used metal gaskets with every engine and have not had problems with them. CR between 10,5 to 11:1. I have had 14 bolts, 10 bolt and currently Merlin heads.