3.0-Rebuild Experts: What HP is your guess?

[Owain]

Hi Gunter,

We'll be doing a dyno day in Vancouver in the spring if you can wait until then. There won't be much tuning going on (depending on how many cars we have to get through) but you will get 2 to 3 pulls and an AFR plot for each run. Then, at least you'll have some numbers and can compare to the other cars that are there that day. Last year we had 16 cars but none with an engine simlar to yours.

If you're interested keep an eye here for an announcement.

[2002M3Drew]

Originally posted by Carrera3.5L
I apparently haven't read as many books as you (and I certainly don't believe everything I read as I've often witnessed the opposite) so I guess I'll agree to disagree, but I have seen/built/driven many of these same engines and on the dyno these popular and smoggable 3.2L CIS spec engines didn't make 220+ at the wheels (Andial used engine dynos because chassis dynos didn't exist back than but I'll even assume 15% driveline loss for argument sake and convert back to whp). I've also been fortunate to have driven many of these combos in the cars in those years, from 3.2L conversions just like Gunters all the way to a 3.0L>3.6L CIS w/ 964 cams that was done in 1990 when the 76.4mm crank first became available.

At least Jerry Kroeger and a couple of others appear sane and have a voice of reason...

Gunter, many chassis dyno operators charge extra for a/f monitoring and graph (some don't) but many also won't touch your car for liability reasons unless you specifically hire them to do so. If you envision yourself tweaking while strapped down on the dyno, I would suggest getting a flat rate so you can do multiple pulls as needed rather than paying for 2 or 3 pulls and than having to pay again if you're not happy with the results and want to tinker. Depending on the dyno operator, some are willing to work with you on price and some aren't.

My comments (whether in this post or in previous ones) also shouldn't be taken as a slight against you or against your motor, I hope that you find the horsepower you are seeking and expecting, it's just my experience (and take that with a grain of salt if you wish) I don't see 220+ at the wheels with a small displacement increase, "normal" CR, CIS and a mild camshaft profile...I can say that it will make a significant difference over what you have now and hopefully you will be happy with the end result.

200 SAE at the wheels on a Dynojet (or approx. 235 crank for those dyno or mathmatically challenged) with a nice flat torque curve is realistic and something I'm sure you would be pleased with.

Ralph

In all fairness, I havn't built or rebuilt as many motors as you apparently have, and I would always choose experience over reading!

I also agree that many power claims of mods are way overstated.

I'll have to go back to the book I was referring to and check it out...I know there were several different 3.0 rebulds displayed there...a 3.0, a 3.2 from a 3.0 and a 3.4 from a 3.0....different cam options, exhaust options, etc.

[Gunter]

Originally posted by Owain
Hi Gunter,

We'll be doing a dyno day in Vancouver in the spring if you can wait until then. There won't be much tuning going on (depending on how many cars we have to get through) but you will get 2 to 3 pulls and an AFR plot for each run. Then, at least you'll have some numbers and can compare to the other cars that are there that day. Last year we had 16 cars but none with an engine simlar to yours.

If you're interested keep an eye here for an announcement.

Owain:
Thanks.
Where in Vancouver is the Dyno?

[Owain]

Originally posted by Gunter
Owain:
Thanks.
Where in Vancouver is the Dyno?

Kinetic Motorsport in Surrey. Here is the thread from last year's visit.

[Gunter]

Some more questions:
Re: Crank vs. wheel.
When HP-figures are used for "at the wheel", what gear is the transmission in?
What gear is used on a Dyno?
Thanks.

[Bill Verburg]

Originally posted by Gunter
Some more questions:
Re: Crank vs. wheel.
When HP-figures are used for "at the wheel", what gear is the transmission in?
What gear is used on a Dyno?
Thanks.

The dyno operator needs to input all of the following cwp, gear, dynamic loaded tire radius and atmospheric conditions. If this isn't done correctly all of the #s will be biased one way or another. This is one of the ploys used to put up big #s that aren't really there.

As long as the #s are correctly entered then any gear can be used but it's best to use as close to 1:1 as possible to remove another issue, inertial drag of the driveline components, from the equations, there is far more of this in lower gears than in upper

The best most accurate #s short of an engine dyno come from Dyna-Pak dynos, they at least remove the tire from the equations and they also remove a lot of the drama that a poorly secured car on a dyno can create.

[Gunter]

Thanks, Bill.
What's cwp?

[dfink]

I will go with 210 rwhp only based on my stock 3.2 with B&B muffler. I would think with the mods he would out pull a stock 3.2

[Kemo]

Im guessing 208.7 rwhp...

[Gunter]

So, what's cwp?

[Bill Verburg]

Originally posted by Gunter
So, what's cwp?

crown wheel & pinion aka final drive ratio, ring & pinion

[Gunter]

Many thanks.
I am beginning to understand a lot more about the Dyno-issue.
In the spring, I'll tag on with a group going to a Dyno in Vancouver.
The HP/torque issue is secondary to me; mostly interested in having the correct AFR throughout the RPM-range.
I think the distributor plays a major role in this.
My 3.0 did run very well with the standard 5deg BTDC.
I remember posts were people set their 3.0 liter to maximum total advance.
Didn't have any success with that; as soon as I go more than 5deg BTDC, it didn't run well in idle.
Now, with the SS 3.2, I plan to experiment with the timing to find the optimum setting.
Any thoughts?

[Drago]

Originally posted by Gunter
Any thoughts?

Carbs make more power.

Can't wait to see and hear the new lump Gunter!

[Gunter]

Originally posted by Drago
Carbs make more power.

ONLY IF THEY ARE ADJUSTED RIGHT

Can't wait to see and hear the new lump Gunter!

SAME HERE

Will you post pictures of whatever mods you plan for the new addition?
What does it need?
Is it running?

[Drago]

Originally posted by Gunter
Will you post pictures of whatever mods you plan for the new addition?
What does it need?
Is it running?

Are you talking about the SMURF?

It's getting new torsion bars (21/29), SC aluminum front cross member, SC rear banana arms, SC brakes all the way around, new spring plates, an early S thru the body sway bar in front and a later style bolt on SC rear bar. Koni Red struts and inserts up front and Koni Red dampers in the rear. All bushings will be inspected and replaced as required.

I also have a f/g S front bumper, an early style dual out muffler and H-4's on the way shortly. I'd also like to add a f/g rear bumper at some point.

All mods will be reversable to stock condition.

[Gunter]

Sounds good.
Will you change the 4-cyl. 912-engine with Solex carbs to something better?

[boxermania]

Didn't have any success with that; as soon as I go more than 5deg BTDC, it didn't run well.

Gunter

In your last post I think that you have confused initial advance and total advance.

Initial advance is when you time the engine at idle.....basically the engine is turning very slow and you are firing the plugs at a crank rotation that will generally be conducive to a smooth running engine.

Total advance is the initial plus the distributor advance. Inside the distributor, there is a cam with weights that will advance the timing as the RPM increase, via centrifugal force. The reason for this is that as the engine RPM increase so do the opening and closing of the valves and the filling and emptying of the cylinders. The advance is necessary to keep the timing, firing of the plugs, in sync with these events and insure that the engine will run well and produce the designed hp.

So the firing of the plugs will have to change to continue to take advantage of the engine power.......too much advance leads to detonation, too little advance results in loss of power.

[Gunter]

Thanks Al:
I understand the workings of the distributor (Vacuum and centrifugal)
My post should have said: When I adjust total advance to some of the higher/maximum settings some people have tried, the engine doesn't run very well in idle.

[Jess]

Originally posted by Steve Marshall
My 3.0 liter euro motor dyno'd 210HP at the rear wheels. The configuration is the same as you have stated except for the cams and displacement.

No wonder you're so fast, Steve.

My motor (supposedly the same as yours) only makes 186HP at the rear wheels.

Whatcha got in there?

Jess

[Drago]

Originally posted by Gunter
Sounds good.
Will you change the 4-cyl. 912-engine with Solex carbs to something better?

It's a 911T Gunter. 2.0L flat 6-cyl. Weber carbs. 4-speed 901.