using 2 headgaskets?

[burch1990]

opinions/help anyone has would be much appreciated thanks :thumb:

[GDN16v]

opinions/help anyone has would be much appreciated thanks :thumb:
Using 2 headgaskets for/on what car? engine spec?:thumb:lol

[REDTOm]

for what?

for lowering compression slightly? yes

just for the sake of it? not so much.

[burch1990]

1.6 8v turbo

[Pistol Pete]

lol PNG...mindreaders since 1990

[let_nova]

(cough) pikey mod (cough)

[Will F]

No - thats worse than using a compression plate - and thats poop!

[GDN16v]

If you cant afford turbo specific pistons and rods then its probably the only way you can do it. But you'll need gasket - spacer plate - gasket to get the compression you need for turboing!:thumb:

[burch1990]

lmao great, what about machining pistons? im not going to the expense, ive got everything i need just want to lower the compression so i get atleast abit of ragging out of it before it goes pop then i'll just sell the kit lol

[burch1990]

unless there is somewhere i can get forged for reasonable price, ive looked but im guna have to get them custom made by the looks of things which im guessing isn't cheap

[mowgli]

go to a decent engine parts shop & have a look at mk3 astra 1600 petrol pistons.. there is an obscure 8.2:1 option listed in some books........

[burch1990]

i have lol, c16nz? and the nz block because ive been told they are taller which makes the c/r 8.2 because the piston are the same lol

[mowgli]

no, there are shallower pistons..... the block is the same size on all the 1600's......

[burch1990]

sound lol, wot you think bout machining them to take the c/r down abit more? want to get as much enjoyment as i can out of it before it goes pop

[mowgli]

if you machine std pistons, then it is at your own risk, simple as that.....

if you want cheap.... there was a lad who thought his 1.2spi had the same crank as his e16se..... it was not, but he ended up with an e16se with about 1400cc & 7:1cr...... now that sounds like a great start for a turbo project....

[craig green]

There is a C16LZ engine which is prolly just low comp for use with crap eastern european fuels. However I doubt the ringlands are uoto the heat of boost & high revs tbh.

I tried to get some custom low comp forged pistons a few years ago. I sent a well worded email to various UK piston manufacturers & got either a 'no thanks' or no replies atall. Maybe a groupbuy would be more successfull but I still think someone would nee to design them & get the spec right beforehand, which I cant see 10 people wanting to be guinea pigs for IMO.

From my experience, a spacer can work OK. The downfall is that the extra height in the block (effectively) wil throw out the cam timing, which I suppose you can get back with a vernier pulley.
The spacer would need to be between 2 HG's, thats how Courtenay did mine anyway. The plate is laser cut from a high grade of S/S & then some sort of surface process has given it micro dimples which I assume help it seal up against the gasket faces.

You could get a batch of these made for a minimum charge from a laser cutter's. IME they charge a minimum fee & you'd get however many can be made from a certain size of S/S sheet. So groupbuy potential there.

Ferriday engineering are maybe a company to approach to make one from scratch.

[burch1990]

serious? lol 1.2 crank?

[burch1990]

i know what your saying, but i wana keep it low cost. ive got to purchase some pistons 'cause the old ones are fook'd so i wanted to do something with them

[mowgli]

serious? lol 1.2 crank?

he did it & it ran, just badly, as the cr was too low for N/A, but with a supercharger or turbo, it would be ace, and with the short stroke, it would rev like mad

[craig green]

i know what your saying, but i wana keep it low cost. ive got to purchase some pistons 'cause the old ones are fook'd so i wanted to do something with them

I know a lad that machined the std pistons on a Courtenay conversion to try & do away with the plate, they holed, quickly, twice. So it was deemed not sensible on std pistons.

[burch1990]

the low compression vauxhall pistons and a 1.4 crank? any thoughts on that, would the 1.4 rods be advised aswell?

[Stuart]

how much 'booooooooost' are you planning to run? (what turbo etc)

imho aslong as you just turned the boost down a touch and lobbed a load of extra fuel in you can run with std compression.

[Rich]

machine the head? bit on the side of the combustion chamber you can take out?

[david dixon]

Can't you just get cometic to make your a 5 layer gasket?

David.

[Sloth]

it was markd89 that did it. e16 with a c12nz crank, 1480cc and low comp.

ferriday engineering do spacers, that are bonded to the block, so you run 1 gasket.

[burch1990]

well i need new pistons cuause the old ones are fooked lol, and the ones im getting are vauxhall nz 9.2:1 so 1.4 crank and rods should take it down to about 8:1 at a wild guess?

[shrtwrec20]

Ferriday engineering will machine the chambers in your head to give you the compression ratio you want, and also re machine your valve seats ofc

[burch1990]

how much?

[davidfox280585]

ford zetecs manage machined pistons fine for turboing obviously proper ones are ideal for proper power

[Stuart]

ford zetecs manage machined pistons fine for turboing obviously proper ones are ideal for proper power


but how much meat is at the top of the piston before and after?!?! its a pretty irrelevant statement to make if there is scope to machine them and the gm ones arent...

[craig green]

how much?

Call them & speak to them :thumb: (ferriday) Likewise Google them for contact details. :d

[Sloth]

ive personally seen a c20ne with a machined head AND pistons, that was at 7.2:1 cr and he ran a t4, and a **** load of boost. **** off boost but jesus it flew on it.