[fozwanger]

What's better

1) Domed piston and larger CC head.

2) Flat top piston and smaller head CC.

Both will give the same cr

 

[jonny z]

engine builds

hi m8, what exactly u shooting for? are u normally asperated? or u boosting? low comp between 8.00-1 9.25-1 best for boosting.
domed piston,s with open chamber heads poss 9.50-1 10.75-1.
domed pistons with quench heads poss 10.75-1 13.00-1 (only good for race fuel) really depends what ur looking for m8 cheer,s jonny z

 

[fozwanger]

Here goes,

Thought I gad it all sorted, all the bits I need, high comp heads, also domed pistons, couple of cams, etc etc.

It then turns out that the heads that I was sold as HC heads were not, they too have a large cc.
Ok, that means I can use my dome top trw's and run NA with my tunnel ram etc etc, 10.3ish :1, fab.
I have been offered another set of SCJ heads with the big valves and with stock pistons will give about 9.4:1 again, good.
Dome tops with scj heads over 14.8:1 no good for the street.
My last moggy was TT and I loved it. Totally mental, loved it.
As you've worked out, seen tt set up for sale and it has got my mind whirring.
The deciding factor will be if I bought them. Then that would then set thing sout for me.

If not, I have the chioce of running flat tops and small CC or dome top and large cc.

Can you see the dilema I'm now in.
Why is nothing ever simple?

 

[jonny z]

hi m8, isn,t it good to have to many choice,s, i recon flat top,s with the large open chamber,s will give good low comp for a lovelly set of tttttttttt, go for it bud, hey u might even have some bit,s left over for me, cheer,s jonny

 

[fozwanger]

Well if I do get the TT's then I'll have a lovely set of 12CC forged TRW speed pro pistons up for grabs and a set of ally rods and matching gudgeon pins up for grabs.

 

[firebird68]

In theory flat top pistons and a small chamber head are the most efficient as they promote faster flame travel/combustion.
In the real world a domed piston in a 'smog' head with a lager chamber work well, I built a 350 chev using large chamber 70s heads with domed Badger pistons, I installed a fairly mild Comp Cams cam at the same time.
These budget mods transformed my engine and its still running strong 10 years later.

 

[fozwanger]

If you haven't already heard, my mind was made up for me as I've bought a twin turbo set up so need low compression.

Yee Haa!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!