[i82much]

Knowing nothing about a Pontiac engine other than (1) it has 87 cc e-heads with the e-head combustion chamber, (2) 10:1, and (3) you dyno'd it with a bad distributor that only let you put 21 degrees total timing in it ... how far off do you think it would be from the numbers you'd get with 36-40 degrees of timing? made 535~ish hp.

I know this isn't a very exact science ...

[Geronimo]

I am going to say you may find anywhere from 25-70 horsepower from more spark lead and possible fuel tuning. Sounds like a nice engine indeed.
Geronimo

[Elarson]

It would make 835 hp with the 300 hp of nitrous that you should spray to roughly match the 21 degree timing.

Sorry....couldn't resist.



Eric

[David Holmberg]

On Pontiac Dude's pump gas motor about 10 years ago, we found 50HP with a 4 degree change.

[i82much]

Thanks guys. Wow that is crazy, 50 hp from 4 degrees. I am thinking there is no real way to quantify this.

[i82much]

Originally Posted by Elarson

It would make 835 hp with the 300 hp of nitrous that you should spray to roughly match the 21 degree timing.

Sorry....couldn't resist.



Eric

So you're saying I should leave it there

[RAIV-Z]

Originally Posted by David Holmberg

On Pontiac Dude's pump gas motor about 10 years ago, we found 50HP with a 4 degree change.

4 degrees in which direction?

[cosgrove]

Exactly why can't you advance the timing?

[i82much]

Originally Posted by cosgrove

Exactly why can't you advance the timing?

I think the mechanical was only giving 4 or 5 degrees and didn't want to go past 16 on the initial.

[i82much]

specs are 505, 325 @.600 e-heads, 2.19/1.77, XR280R w/ 1.5 rockers and 1 7/8 Doug's headers. Torker II and an 850 double pumper (old style aka a "real" 850).

[cosgrove]

Steve, Is the engine still on the dyno?

[i82much]

Originally Posted by cosgrove

Steve, Is the engine still on the dyno?

Nah, long story but this is all happening in a different time zone ... I am going to just go ahead with the install rather than try and get more dyno time.

[GTO Dan]

Originally Posted by Elarson

It would make 835 hp with the 300 hp of nitrous that you should spray to roughly match the 21 degree timing.

Sorry....couldn't resist.



Eric

The appropriate answer for the Race Forum.

[David Holmberg]

Originally Posted by RAIV-Z

4 degrees in which direction?

IIRC 36 to 40 or 32 to 36, it's been many years...

Originally Posted by i82much

Thanks guys. Wow that is crazy, 50 hp from 4 degrees. I am thinking there is no real way to quantify this.

Well we were on a chassis dyno at the time. It was a nitrous combo so there wasn't much NA tuning done before, but it put down 601 to the rear wheels NA.

[i82much]

Originally Posted by David Holmberg

IIRC 36 to 40 or 32 to 36, it's been many years...



Well we were on a chassis dyno at the time. It was a nitrous combo so there wasn't much NA tuning done before, but it put down 601 to the rear wheels NA.

I guess in a sense the bigger numbers are more promising. I was hoping for close to 600 at the flywheel but wasn't sure whether being off 15-20 degrees was enough for a 70 HP loss or not. It seems at least plausible, if not likely, that the engine will approach 600 HP once the distributor issue is straightened out. As it stands, I'll probably have to check it out on a chassis dyno ...

[60man]

Originally Posted by i82much

specs are 505, 325 @.600 e-heads, 2.19/1.77, XR280R w/ 1.5 rockers and 1 7/8 Doug's headers. Torker II and an 850 double pumper (old style aka a "real" 850).

On my old 505 combo with 325 KRE D-ports & flat tappet cam - 12.5CR- it made just shy of 600 HP @ 31 degrees of timing. That was with dual AFB's.

Just get motor running and then set the total advance.
Who needs initial other than for starting..