4 replies to this topic

[CH007]

Hello All,

I am slowly pulling together components and tooling for my engine build. I am doing the 8V twin cam conversion from a BMW K100. I will be running EFI and T3 turbo and looking to run high boost although turbo will be changed for something more efficient later as the project progresses.

I am advised the CR would be good around 8.5 - 9:1 range for this head. This would probably lead to not much of a dish in piston needed.

My main considerations and the piston crown thickness for both machining pockets and taking excessive boost and also ring land etc to again handle the conditions.

I notice from reading Turbo Phil recommends the mega range from minispares and these seem good value for money. Or should I bite the bullet and go for omega forged?

I then move onto crank and rods but from my reading people have ran the standard cranks upto massive power without major probs?? I will be fitting centre strap while engine is apart for rebuild along with under crown oil jets to aid cooling of pistons.

Any advice would be great or further reading elsewhere

[Wil_h]

I think you have it, If you can afford omegas then use them.

Considering that you will have to make a manifold for the turbo, it's more sensibel to choose the right turbo now. I say this because if you build a manifold for a T3 (which will cost time and money) then you might find you'll need to start again for your new turbo. Having fitted numerous types of turbos and constructed and bodged lots of manifolds, it's worth avoiding if you can.

[CH007]

I think you have it, If you can afford omegas then use them.

Considering that you will have to make a manifold for the turbo, it's more sensibel to choose the right turbo now. I say this because if you build a manifold for a T3 (which will cost time and money) then you might find you'll need to start again for your new turbo. Having fitted numerous types of turbos and constructed and bodged lots of manifolds, it's worth avoiding if you can.

Very valid point regarding the Turbo! Guess I need to go do some more reading of the books I have here first so I understand what the hell I am doing

Tuning is new me in this sense. I trained as a car mechanic when left school but worked in classic cars and the performance tuning never really came into it. Just have the engine running correct. I guess thats all the performance side is! Making sure the components all compliment each other and perform to there maximum.

The forced induction is slowly becoming more clear and am reading a few books at present.

If the budget wont allow the omegas then will go for the turbo mega piston as thats been pushed to some pretty decent powers and boost!

So need to get the T3 and metro manifold etc up for sale sharpish

[Turbo Phil]

If going for a cast piston I'd go for the Omegas over the Mega now, after quite a few recent problems with the Megas. I really do need to update my website ! Lol.

[CH007]

If going for a cast piston I'd go for the Omegas over the Mega now, after quite a few recent problems with the Megas. I really do need to update my website ! Lol.

Cheers Phil, I was looking at the 18cc dish forged but would rather spend a bit less at present and go for cast. I will have a look at the Omega cast then as no point in forged piston really as will be running pretty standard crank and rods albeit balanced and lightened a little.

I have dropped you a PM on TM ref the Carb etc as off work next few days