Blew my engine. Anyone here build a 3.8 or 4.0?

[BYprodriver]

Originally Posted by Bigsmoothlee

So scratch the idea on the 3.6 crank. So you're saying that boring to a 3.6 is the max?

No I'm saying step 1 is install LN 99mm "nickies" for 3.6L this step will cost $7,000 min.

To go bigger will cost alot more with rapidly diminishing returns power to $$ ratio, especially for high RPM DE racing.

I have a 2001 3.6L longblock I will sell for $15,000.

[Bigsmoothlee]

Originally Posted by BYprodriver

No I'm saying step 1 is install LN 99mm "nickies" for 3.6L this step will cost $7,000 min.

To go bigger will cost alot more with rapidly diminishing returns power to $$ ratio, especially for high RPM DE racing.

I have a 2001 3.6L longblock I will sell for $15,000.

I don't think its that expensive, LN engineering lists the work for $3300, and $4600 if you want the pistons to go along with it.

Or, I can just have LN engineering bore the engine case I just bought from 93mm out to 96mm... but that wouldnt be much fun.

Diminishing returns after 3.6 noted. Im sure your 3.6 is a nice engine, but its out of my price range. Especially since I can handle all of the work.

[jaykay]

I would have thought the difference in cost between between a 3.6 bore and 3.8, 4.0 would be minor compared to everything else and really attractive if you are doing the work yourself. Working with 3.2 heads (five chain) I would have also thought 3.8, 4.0 would have bumped up the torque significantly with at least another 100Hp peak with nice drive ability.

[BYprodriver]

Originally Posted by jaykay

I would have thought the difference in cost between between a 3.6 bore and 3.8, 4.0 would be minor compared to everything else and really attractive if you are doing the work yourself. Working with 3.2 heads (five chain) I would have also thought 3.8, 4.0 would have bumped up the torque significantly with at least another 100Hp peak with nice drive ability.

You need a 3.6 crankshaft & carrier & rods & LN pistons. For anything more stressful than auto crossing I would insist upon aftermarket rods. 3.8+ will have LOTS of low rpm torque, enough to increase autocross times.Peak HP I would guess would increase 8-12% depending on head work & bolt-on external parts.

[jaykay]

Yes I should qualify 100hp as 100 over the stock 3.2.

And so we are talking 8 to 12% projected peak power increase for the 3.8 over the 3.6. This change in displacement will perhaps put us at 375 BHP peak while having to upgrade the crank, crank carrier, con rods...with no head options to fully realize the gains to be had. Now I see where the expense is for little result.

How is it that no crank, carrier, conrods are required for the 3.6?

Doesn't Eric at HRG have a 4.0 in his car.....5 chain? I guess with a race car and motec you can just load up a 3 chain in a car that originally had 5 chains.

Jeez I would hope that the result would be better than than the 944 turbo S and big aftermarket turbo I drove on the weekend

[Jake Raby]

Size doesn't matter. When I found efficiency, I found power.


Bigger isn't better in most all cases. If It were I'd only be building my 4,2L engine, and nothing else.

To big build and optimize it, costs real money. Building it big without coefficient design, means it'll be a pig. I see people do this all the time, and the engine isn't good at anything.

Other than burning gas.

[jaykay]

So this begs the question: What needs to be done for 3.2 to 3.8 to avoid piggish ness?

Will the 3.2 heads ported suffice?