Hi guys, been away for a bit, just picked up a new cyclinder head.... need opinions on wether or not too swap it to lower the comp ratio on my engine... does anybody have any input? i am going getting the engine fitted with a standalone system in the coming months but i would want to know were i stand. if it wouldnt make a difference i would leave my own but if it will there will be a high comp head going cheap for someone!

the cylinder head is not going to make a huge difference in you engine compression. changing the pistons on the other hand...

well, there was no pinking before on the cyclinder head before it was skimmed down to the last. i just want to stop the pinking on the engine, i have a second cyclinder head bought already even if i dont need it its there for parts. no need to go changing pistons, were running 95 ron here. i just want to know how i can stop the pinking and gain power. the comp was 13.9 before until it got skimmed and bounced to 16 due too a smalll dent which had to be skimmed out of it . also theres a .8 mm cometic gasket in it. whats your veiws? like i always said, i want 200 bhp and im going to get it even if i have to run on 101 airplane fuel!

13.9 compression? yes that needs race fuel only! way too high for pump gas.

Pistons need to be changed to gen2 or lower, or machined down

New head won't make that much difference

Gasket needs to be as thick as possible when skimming - I use 1.6mm
to limit compression

Power is all good, but if something's not right you end up with less than before
Compression is not the way to make power in these motors
Build it stock, cams, porting, TVIS delete, lightening & balancing,
intake & exhaust etc are the way to go

Power = unreliabilty, ie the more power you make the more TLC and money it will need

i was just getting the new head to reduce the comp a smaill bit, i want to keep the pistons and the comp ratio because of the mission im on with 200bhp, i found a local dealer for kelford, turns out hes my mates boss, he works in motorsport engineering and he recons theres defo a chance in getting 200bhp, he build a 4age up to 240bhp, thats pretty good, so hes going to get his boss on the case, the company i was talking to about the ecu said defo on a new head, and they can run multiple maps, im planning on getting the st205 gasket that rich always recommends, hopefully that will make a difference. when the engine was first built the power was greatly improved, and with this new head comes with all the extra parts that are broke in mine so it should make a difference, we run on 95 ron in ireland so it aint so bad, the local petrol station has 96ron so im not too pushed, if i could get the motor at an even 13 bar or so id be happy...

i dont want to be throwing money down the drain by changing pistons, if i was going to do that id slap on a turbo (which i dont want) but thats what i would probably do, i wanted 200bhp... N/A even if its just for a second! ;)

i know its impossible but i will get there with time and paitence, it will be my weekend cars soon as i get my other going, that way i can work on it im with no need to rush anything

what you think?

You said it right there, can't agrue with that logic

This is what I'm talking about

stig, i hope you know that that is the photo that you showed me when i first joined that inspired me to keep going!

Yep, reminds me of the guy who kept banging his head on the wall -
because it felt sooo good when he stopped!

hah, i know what your trying to say, the way i see it now too is there was so many of these cars scrapped in ireland that the prices are still seriously high. about 3000 for a cleanish one. i would like to keep it as original to the gen 4 as possible, with the power of a gen 6...