The V8 Owners Forum -

That someone on here found pistons for £8 each? - or something along those lines...! I need some +20thou pistons- standard but obviously low price would be nice! Have done a search on here but couldnt plough through all 411 results!

Also what sort of RPM can I really expect standard lifters to work well until? (I think Des' tuning book is made for people who have a lot more money than me- it also forgets that all these terrible standard parts have sufficed in hundreds of thousands of engines over the last 40 odd years!!!!)

About 5500rpm before they start to pump up is what I read.

Chris.

topcatproduction wrote:That someone on here found pistons for £8 each? - or something along those lines...! I need some +20thou pistons- standard but obviously low price would be nice! Have done a search on here but couldnt plough through all 411 results!

Also what sort of RPM can I really expect standard lifters to work well until? (I think Des' tuning book is made for people who have a lot more money than me- it also forgets that all these terrible standard parts have sufficed in hundreds of thousands of engines over the last 40 odd years!!!!)

Des reckons that the standard lifters will go to 5,800RPM before they start to pump up. It also helps if you set the preload to 20 thou. I found that the only way to get them spot on was adjustable pushrods. (Or rockers I guess!)

You need to be careful when buying standard lifters, there are some dodgy ones on the market that have not been machined correctly. Well this is what RPI told me just before flogging me a complete set of theirs!

My 4.6 lump will rev to 6k without any issues (power is starting to tail of around 5800'ish but that might not be a lifter issue).

Don't know about the pistons! (But at 8 quid each I would hazzard a guess at about 10 minutes at 2K RPM!)


Pete

im looking for some 20thou over pistons aswell,

i also find the tuning books confusing, im going for a standard rebuild
basically
aftermarket cam
mark adams chip
arp mains
double s exhaust

after reading up i think its all i need!

just need to find some decent pistons, i bought a shocking quality piston recently for a rover k series

Real Steel do a set of +20thou high compression 9.75/1 piston for about £140 These were originally used in the Vitesse so should stand up ok.

Do get a decent timing gear set the standard one is crap.

Kevin.

CastleMGBV8 wrote: Do get a decent timing gear set the standard one is crap.

.

indeed, its hard to believe the slack in them, i will check out the real steel ones thanks

That doesnt sound bad- I'm after lower compression if anything- 9.35 pistons at most as I'm SC it, can they be machined down in a mill a few thou?!  Does anyone know what affect the +20 bore has on compression ratio's or extra cc's?  Must be a little bit over 8 cylinders 

p.s. Real Steel- phone or web?

wow just found the real steel web site- my new favorite site!  Pistons are sorted then- seems to have absolutely everything on there- and they have a good name!  The high volume/pressure oil pump kit they do- does that not put a bit excessive pressure thus wear on the dizzy gear as it was already a problem with the little pump?!?!

Some people have reported premature and excessive wear of the cam/distributor gears when they have used the increased oil pressure kit.

As to the increase in capacity of + 20thou rebore will probably give you an extra 40-50cc. and a very small hike in compression.

If you intend supercharging at a later date I suggest you use the composite head gaskets which are 39thou thick and seal better as opposed to the tin gaskets which are only 18thou and will reduce the compression ratio by approx 0.5/1

Kevin.

Yes I was going to use composite gaskets- didnt realise they lowered the comp that much! I am also mildly porting the heads including the shroud around the valves which will lower it a bit more- I suppose 1cc of material could come off from the combustion chamber- not sure how to work out compression ratio's as don't know the small volume when standard!