110HP Per Litre out of a 3.6?

[gab997]

First off, what would estimated cost for reputable shop be to do this with a 3.6 vario?
Secondly, what would reliability be like? How often would top end need refreshed and cost on the refresh?

[CaptainCalf]

Budget $50k for the motor and top end refresh would depend on you and how you use/abuse it...

[gab997]

Would it be motec or carbs? Assumption would be motec, also what type of compression would need to be run? Would increasing displacement save any dollars or not really to get to the 400hp mark?

[CaptainCalf]

Motec or any other ECU supported by your builder/tuner would be the way to go and if you go with EFI you prolly wouldn't even need higher compression or more displacement. Just open up the intake and exhaust to maximize flow and your HP goals should come right into view...

[Steve@Rennsport]

Originally Posted by CaptainCalf

Budget $50k for the motor and top end refresh would depend on you and how you use/abuse it...

Thats close,....

Engine longevity depends on max RPM, compression ratio, and how its operated.

These can last anywhere from 25 hours all the way to 125 hours.

[hcoles]

no one is counting but it sounds like $~70 to $~14 per lap

[Eagledriver]

Originally Posted by hcoles

no one is counting but it sounds like $~70 to $~14 per lap

That would be true if you had to start over again after the 100 hours or so. You'd only need to inspect and machine/replace parts of the engine, not the whole thing.

The only way to get that much power is RPM. Probably close to 8500 RPM. That means all the expensive goodies.

-Andy

[MBruns]

We run a 3.8 with carbs in HSR/SVRA that is north of 415hp with 964 heads, our range is 4500/7500 if you shift where it feels good and look at the tach its usually at 7000, we can't keep heads from breaking 30 hours is about it, we have a new set of Xtreme heads that are going on in the next week or so and the flow data is much better, I will let you know how this turns out
Mike Bruns JBRacing.com

[JeremyD]

^^^^^ and Greg - that's the guy that can build it for you...

[gab997]

Mike,

Let me know how the new heads end up running, what is the refresh cost after the 30 hours?

We run a 3.8 with carbs in HSR/SVRA that is north of 415hp with 964 heads, our range is 4500/7500 if you shift where it feels good and look at the tach its usually at 7000, we can't keep heads from breaking 30 hours is about it, we have a new set of Xtreme heads that are going on in the next week or so and the flow data is much better, I will let you know how this turns out

Mike Bruns JBRacing.com

[MBruns]

We have been through 3 sets of low time street 964 heads modified to race heads in 4 years with 1 or more heads cracking port to port during the enduro, I have inspected and reused the mains and rod bearings in the last 2 cycles, point being that without the head failures this engine should go 60 race hours before inspection. The Xtreme heads have much more material in places where its needed for this power level, I would be happy with the power levels we have now to have the reliability, but with the flow bench data it should be a good bit better, I will have this on the dyno soon and post the results.
Mike Bruns

[AlfonsoR]

Check what this guy did...and car is for sale for $50,000. Looks like it's worth every penny.

Don't know how to paste a link from Rennlist but it's: Rennlist.com/ web forums/ browse forums/ 911 forum

Thread: FS: Very unique 911 CTR esque w/3.9 na 400hp

[ARCSinAK]

Hi Mike-

Just wanted to say I like the way you think.....clear and concise, thanks for spending the time and $ to find the threshold of air cooled performance...one day after the child is out of college I dream about building a potent 3.8 for street use for my narrow 911...

Aloha-

JED