Decided to have a play with one of the Rover V8's that I have. I've collected a few bits over the years and have decided to build one. The engine in question is a 3.5 with 9.35:1 comp. The piston rings have siezed but they are cheap enough and the bores can be honed as they are well within tolerences. Now I have a choice of standard psitons or low comp, 8.13:1 for a turbo conversion or go N/A. Can't reallt afford a turbo conversion at the minute so wil have to go N/A. Now a year or 2 ago I managed to find a chart that told what other pistons fitted with little or no mods and since then I have a different PC and can't find this chart on the internet anywhere, all I remember is it listed some Ford pistons as fitting and giving 13:1 comp ratio, Buick and Chevy giving upto 12:1. Does anyone know where this list is or find the info I am looking for so I can buy some pistons to give better compression ratio? Thought of having the heads skimmed but would need quite a bit taking of to get to 11-12:1 ratio. All help welcome.
My old P6 3500S had 10.5 /1 pistons, Don't know if they are still available though and I had to run the engine on 5star fuel
You can still get them but want at least 11:1, just trying to find the website with the details of the different pistons on, can't find it anywhere.
Try EGGE obsolite engine parts, they list piston L2152 for the pistons for the Buick 3500 which is the Rover engine. They also list all of the internal parts including gaskets in their catalogue. www.egge.com, very well known American company, their Buick parts list goes back to 1927.
Hi,
I would stick with the stock rover 9.35/1 cr pistons, but look out for a pair of 4.6L stock heads, the 3.5/3.9L heads have a 36cc chamber, the 4.6L
heads have a 24cc chamber, fitting the 4.6L heads to a stock 3.5L engine gives you around 11/1cr without any machining work. When you decide to go
turbo just fit the 3.5 heads back on to return the CR to 9.35/1.
There is no need to lower the compression below stock with the turbo, if you get the fuelling and timing correct and dont go mad with boost
you'll have a much more responsive engine will better MPG than if you lower the CR. I have run 15PSI into a stock rover with megasquirt using
97RON fuel without any detonation, i do the same with the Ford zetecs, 10.5cr 12PSI 266BHP out of 1800cc with careful mapping.
quote:
Originally posted by BaileyPerformance
Hi,
I would stick with the stock rover 9.35/1 cr pistons, but look out for a pair of 4.6L stock heads, the 3.5/3.9L heads have a 36cc chamber, the 4.6L heads have a 24cc chamber, fitting the 4.6L heads to a stock 3.5L engine gives you around 11/1cr without any machining work. When you decide to go turbo just fit the 3.5 heads back on to return the CR to 9.35/1.
How much are a pair of heads compared to a set of pistons?
BaileyPerformance - 15/5/11 at 04:48 PMsearch ebay, a pair of heads would set you back £150, but you wouldn't need to get any machining done and the chances are the later 4.6L heads would be in better condition that an old 3.5L pair, plus the later castings have slightly better ports.
Use your old 3.5L rockers and push rods, use the 3.5L tin head gaskets NOT the later fiber ones. To get the best out of the compression increase you need an uprated cam, if thats over budget then the late 3.9L injection cam is a little better than the carb cam, worth 5bhp
marcjagman - 15/5/11 at 05:50 PMI have looked on ebay at heads for a 4.6 and they do go for silly money, some on today at £120 but chances of them being that price when I want them is pretty slim I think