well, I'm done. The whole shebang...

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In 2001 I did a 408 that made 565 HP at 5400 RPM (I don't remember the TQ because it's not that big of a deal to me but TQ was in line with the HP).

That was on ported Eddies, 1.875 headers and a very, very small Cam Motion hydraulic roller. That engine should have made 625-630 if we went with a solid roller and turned the engine 6500.

So if you get anything less than 620 I'd be looking for more HP.

BTW and FWIW...I would have tried to squeeze a bit more lift out of it. I think you should have tried to NET .725 or so. There is HP in lift.
 
Well spent 5 hours today on the dyno. Well not 5 actually ON the dyno, but 5 hours there. I think I'm happy.

Be advised the results posted are with my motor running a "inhouse" Holley HP 650 carb. Yeah SIX FIFTY.

Had a huge problem with my 950 and couldn't run it.....so being strangled from 6000rpm on, we got

530 HP at 6000 and peak torque was 514 at 4900 rpm.

We DID do one pull to 6600 and HP and torque were unchanged from 6000 on to 6600. I mean freaky unchanged. HP just hung at 530 and torque at 464 all the way from 6000 to 6600. He seemed to know it was gonna happen somewhere in the curve, I guess the 650 reached its limit right there at 6000.

He advised at that point, no reason to run it past 6 grand. Just couldn't get the air it wanted.

I don't have a clue what it will make with my 950........dyno guy told me I was leaving at LEAST 30-35 HP on the table.

The great news is no leaks, good oil pressure, and by the last pull he said the blowback gauge showed (2), indicated outstanding ring seat. NO smoke.

I can tell you it really sounded fantastic. Really "revvy"....if ya know what I mean.

It was so friggin frustrating I had to run his little carb, but so good to know that all is OK and it's making pretty good power.

He did very curtly tell me to can my jetting idea and put both 4.5 powervalves back in with 78 jets front and rear and I should be real close with my own carb.

So what are your thoughts, guys? Do you feel I was leaving 30 or so horses on the table with that 650 carb?
 
All darn winter during this build, I posted a million questions and other threads about this and that..

Thanks all of you for chiming in and giving advice and opinion and good luck wishes.

Just wanted to NOT forget to mention that.
 
Well looks like I was way off. I wonder what it was. I really thought you'd be close to 600 horse keeping it under 7000. Those heads sound great and should make power. I bet you could pull even more compression depending on the gas you got in your area.

I'm sure you're leaving a ton on the table with that carb. A lot more than 30 horse I would think. That carb isn't big enough even for street. You'd want at least a 750 on there just for cruising. I'd be really curious what your numbers would be with a bigger carb on there.
 
If torque and horsepower remaineed unchanged from 6000rpm to 6600rpm i'm afraid it sounds like a broken dynamometer.

If torque remains the same and rpm increases. then horsepower increases with it.

If Horsepower remains the same and rpm increases, then torque decreases with it.

horsepower = (torque x rpm) / 5252

464 lb/ft @ 6000 RPM is 530hp

464lb/ft @ 6600 RPM is 583hp

If your torque and horsepower don't intersect at 5252rpm then something is seriously wrong with the dyno equipment.
 
I bet it left 40 or more on the table,no chance to tune it at all.Jets and timing can be that much
 
puts it real close to what I estimated. You're real close to my setup, just a tad below, so 575+ should be doable with the 950.

Did you record any of the dyno runs?
 
I was expecting around 585hp.
That 650 would be costing a fair amount of power, shame you couldn't grab hold of a spare 950 while it was on the dyno
 
I originally figured I'd be really happy at 550, so I can't complain. Awful close with a small carb.

My dyno guy, machinist, head guy thinks the Indy X heads are kinda holding it back. Although they did flow well, like he said before, velocity isn't REALLY great and the exhaust ports are "as cast". I'm gonna just have to be happy with it though.

As I look back I just shoulda shelled out and had MRL port me a set of ProComps. I get the feeling I'd be waaay up there HPwise had I went that route. Just didn't have the dough at the time.

Just thrilled as hell everything else is good. Had a real stinker last year and really looking forward to spring.

I do have the last 3 pulls to 6000, Fred. Didn't get the break in pulls or 6600. Curious what heads you're running?
 
If torque and horsepower remaineed unchanged from 6000rpm to 6600rpm i'm afraid it sounds like a broken dynamometer.
If torque remains the same and rpm increases. then horsepower increases with it.
If Horsepower remains the same and rpm increases, then torque decreases with it.

horsepower = (torque x rpm) / 5252

464 lb/ft @ 6000 RPM is 530hp
464lb/ft @ 6600 RPM is 583hp

If your torque and horsepower don't intersect at 5252rpm then something is seriously wrong with the dyno equipment.
Click to expand...


Very good point... both numbers can never stay the same as rpm increases.
So you only have a temporary reading at 6000 but not what the engine is really capable of.
 
Ironmike said:
Well spent 5 hours today on the dyno. Well not 5 actually ON the dyno, but 5 hours there. I think I'm happy.

Be advised the results posted are with my motor running a "inhouse" Holley HP 650 carb. Yeah SIX FIFTY.

Had a huge problem with my 950 and couldn't run it.....so being strangled from 6000rpm on, we got

530 HP at 6000 and peak torque was 514 at 4900 rpm.

We DID do one pull to 6600 and HP and torque were unchanged from 6000 on to 6600. I mean freaky unchanged. HP just hung at 530 and torque at 464 all the way from 6000 to 6600. He seemed to know it was gonna happen somewhere in the curve, I guess the 650 reached its limit right there at 6000.

He advised at that point, no reason to run it past 6 grand. Just couldn't get the air it wanted.

I don't have a clue what it will make with my 950........dyno guy told me I was leaving at LEAST 30-35 HP on the table.

The great news is no leaks, good oil pressure, and by the last pull he said the blowback gauge showed (2), indicated outstanding ring seat. NO smoke.

I can tell you it really sounded fantastic. Really "revvy"....if ya know what I mean.

It was so friggin frustrating I had to run his little carb, but so good to know that all is OK and it's making pretty good power.

He did very curtly tell me to can my jetting idea and put both 4.5 powervalves back in with 78 jets front and rear and I should be real close with my own carb.

So what are your thoughts, guys? Do you feel I was leaving 30 or so horses on the table with that 650 carb?
Click to expand...

If you could post up a sheet it would clarify some things for guys that are used to looking at dyno data.

These are a few of my thoughts. The carb being a 650HP is probably not as big of a restriction as you might think. I test 358 DIRT SPEC head engines 10.5 comp, 650HP, roller cam usually about the same as yours @ .050" and routinely witness 550+hp 480 tq with some really good ones 575+ hp @ 6600. I know 50 cubes more is going to put more demands on the carb earlier in the rpm's however it still illustrates the HP potential. Now all of this is assuming the 650 you were using was a good one.

For the guys on here thinking this should have been well over 600 hp, please believe me when I say that 580 hp is very difficult to achieve with a stock/OEM port head arrangement and without offset rockers. Or simply put--I don't really care that the heads flowed near 300 cfm, If the CSA is not there it will never RPM and there goes your HP potential. I also doubt you have a too little velocity problem with those heads--more like too much velocity. I will admit that with the cam you are using I would have guessed 540-550 hp and it may show up with a larger carb. I have tried it many times and often was only worth a few numbers at best.

The reason I'm asking for a dyno sheet is to rule out things like carb is restrictive (did you get a manifold vacuum reading?) Or maybe you are running into valve train instability @ 6000 rpm (Airflow through the turbine can determine this) Also the exhaust being restrictive can cause power to flatline.

All in all though, when you don't have leaks or smoke and/or parts failure it is a good day on the dyno and if the motor is sealed well with no blowby you can rest easy. It also stands to mention that maybe the dyno you used is very truthful, which isn't a bad thing. Not referring to the flat line power curve here, just the reasonable numbers it recorded.

Again these are just my observations and ideas. J.Rob
 
Wow, congrats!
As most said, no failures, leaks or smoke is a solid feat in itself. Those are some really respectable numbers.

This gives me confidence in my 425ci stroker build I'm doing now, can't wait to get it done!
 
IronMike, As my signature eludes to, mine are W2s, ported and built by Brian at IMM. The motor is all by IMM, too. I think that Carter pump is holding you back over 6000 some too. I switched from that to a Magnafuel 275, with line size increases too, and noticed much better throttle response over 6500. This is on the street. The car didn't feel like it ran out of gas anymore, and pulled much harder to 7K.
All of my dyno runs at IMM are with an electric fuel pump, never with the mechanical.

My gross lift is .698 too. Compression is close to yours also.
 
I've said it here before, the dyno for me is more of a diagnostic thing to make sure all is well BEFORE wrestling the thing into the car. Had a rear main leaking real bad years ago right after a rebuild and had to yank it right back out. Never again.

As for the fuel pump, i don't think it's an issue. Pressure was great, pounds per hour well under the pumps capability. I run my own pump and mechanical water pump on the dyno. If I'm gonna get numbers, I kinda want real numbers.

Talked to the dyno guy today, he's going to mail me all pulls we made. His dyno is calibrated more often than most. He told me last year, it's not an engine builders dyno, it's set for your motor to give real numbers. I know there are guys that "fudge" things a bit to make the customer happy. Not my guy. I've seen dyno sheets that just made me chuckle. Jeez I had one once..

Oh yeah, it did not "die" after 6000....it just quit making power, holding steady. With that cam, intake, compression, etc, he thought it should make power past 6500. Carb HAD to hold me back somewhat. His words. Nothin wrong with his dyno.

Manifold vacuum was monitored, I hooked up the line myself, but It's not on the sheets I do have now.
Don't think I I have valve train instability, either. And what does "air flow through the turbine" mean? I have no clue what turbine you are talking about.


Once I get back to work I can scan a couple pulls and post em up.
 
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