[Hillard]

Backstory...I raced at the Pontiac Nationals for almost 20 years straight until we sold the car about 5 or 6 years ago. It's been killing me to just spectate ever since. So, I decided I was going to throw together whatever crap I can find to get my 69 GP running again just to run street class. I've been acquiring parts to build a motor for it and to update the car to handle the new motor, but I've lost patience. So using some parts I have for the good motor, and scrounging whatever else I could find, here's what I came up with.

1975 400 (not the bad casting), completely stock with 205k miles on it. Tore it down to the shortblock. Not going to rebuild it as their is not enough time. Using my ported Wenzler heads (don't know the flow but the ports are big), approx 10.75:1 compression, Comp 276AH-10 hyd flat tappet, probably my unported Northwind intake w/ a Demon 850, 2500 stall, 3.90 posi. Car is 4050 lbs.

I know what you're thinking, should have just waited till I finish the good motor and do it right. I normally would have given the same advice. Just can't wait anymore. So what do you think? Will it run? Will it survive? If it survives, will it even spin a tire in gravel?

[slowbird]

I've got no idea what it'll run but the cast pistons and stock rod bolts wpuld be my concern. Something happens there and your Wenzler heads might take a beating.
Please let us know how it runs, it'll be interesting. If it stays together it might surprise all of us.

[Hillard]

Originally Posted by slowbird

I've got no idea what it'll run but the cast pistons and stock rod bolts wpuld be my concern. Something happens there and your Wenzler heads might take a beating.
Please let us know how it runs, it'll be interesting. If it stays together it might surprise all of us.

Yeah I thought about the possible abuse to the heads. I'm certainly taking some risk there, but I know the risk and am willing to accept it. That's also one reason for the fairly mild cam, keep the rpms down. Of course the gears aren't going to help that. Wishing it had a 3.55

[steve25]

Do you have a windage tray in the motor and at least a stock baffled TA pan?

Oil airation is a big cause of Rods coming out of the side of the motor with stock set ups even at only 5500 rpm, no less the 5800 rpm the stock Rods are good for with a 3.750" stroke motor.

[Mark G]

My concern would be the piston /rod combo .I lost a motor about 25yrs ago put a good set of heads & cam stock block 400 .block ..Well rods piston decided to leave block at 90 plus mph ,Driving in your own oil at speed really gets your attention.. ..

[Hillard]

Originally Posted by steve25

Do you have a windage tray in the motor and at least a stock baffled TA pan?

Oil airation is a big cause of Rods coming out of the side of the motor with stock set ups even at only 5500 rpm, no less the 5800 rpm the stock Rods are good for with a 3.750" stroke motor.

Going to go ahead and risk my Canton baffled oil pan. So it will have a little extra oil in it also.

[Hillard]

Originally Posted by Mark G

My concern would be the piston /rod combo .I lost a motor about 25yrs ago put a good set of heads & cam stock block 400 .block ..Well rods piston decided to leave block at 90 plus mph ,Driving in your own oil at speed really gets your attention.. ..

Actually thought about putting a diaper on it. Figured I'm going to need one eventually with the motor I'm planning on building, so just add it now and I'll have it for later. Also keeps the other racers from being mad at me for down time.

I should add that even though we're talking about possible engine catastrophe, I have run stock rods with more rpm and power than this is going to have with success. And I know the history of this motor as it was in my Dad's personal vehicle and he always used AmsOil. Yes it has a lot of miles but I know it was taken care of. So I'm really hopeful I can take it to the track a few times this year, and maybe have my other motor ready for next year.

Hoping for the best, preparing for the worst.

[slowbird]

Originally Posted by Hillard

Actually thought about putting a diaper on it. Figured I'm going to need one eventually with the motor I'm planning on building, so just add it now and I'll have it for later. Also keeps the other racers from being mad at me for down time.

I should add that even though we're talking about possible engine catastrophe, I have run stock rods with more rpm and power than this is going to have with success. And I know the history of this motor as it was in my Dad's personal vehicle and he always used AmsOil. Yes it has a lot of miles but I know it was taken care of. So I'm really hopeful I can take it to the track a few times this year, and maybe have my other motor ready for next year.

Hoping for the best, preparing for the worst.

The rods aren't as scary to me as the pistons are. As long as you don't get too aggresive with time and run good gas, you'll be ok but putting a diaper on is a very good idea.

[BruceWilkie]

Smaller cam will probably be quicker. Summit 2800 is quick to 4k then done. The 2801 will be done @ 5k rpm.

[adam woodmancy]

I’ll say 8.0s/12.9@105

[Hillard]

Originally Posted by adam woodmancy

I’ll say 8.0s/12.9@105

I would be SUPER excited with a number like that.

[adam woodmancy]

Originally Posted by Hillard

I would be SUPER excited with a number like that.

👍. I wouldn’t be surprised if it ends up being a little quicker than that once you get it dialed in a bit.

[Mark G]

Originally Posted by Hillard

Actually thought about putting a diaper on it. Figured I'm going to need one eventually with the motor I'm planning on building, so just add it now and I'll have it for later. Also keeps the other racers from being mad at me for down time.

I should add that even though we're talking about possible engine catastrophe, I have run stock rods with more rpm and power than this is going to have with success. And I know the history of this motor as it was in my Dad's personal vehicle and he always used AmsOil. Yes it has a lot of miles but I know it was taken care of. So I'm really hopeful I can take it to the track a few times this year, and maybe have my other motor ready for next year.

Hoping for the best, preparing for the worst.

Yes a diaper is your friend .in the 80/90 we had nothing most guys never ran much safety stuff ….

[Hillard]

Originally Posted by Mark G

Yes a diaper is your friend .in the 80/90 we had nothing most guys never ran much safety stuff ….

2 main reasons I would run one. Obviously the safety factor. I would hate to lose my car due to this. It's the first car I ever owned. Had it since July 1985.

Other reason is the fact that I know this setup could be suspect to damage, and if I was the one sitting in the lanes waiting for the track to be cleaned up and knew some idiot was running a motor that he knew was marginal and ended up oiling down the track, I'd be ticked. So out of respect for everyone else, I'll do my best to minimize any possible downtime.

[adam woodmancy]

Hilliard, my combo is almost just as bad and it has lasted me many many years. Very mismatched, but it’s what I have and it’s what I can afford. When I do break the motor it’s always something like the oil pump drive shaft, or harmonic balancer. Granted I do have updated rod bolts and forged flat tops, but they’re still speed pros and they’re still heavy. I think it might treat you well as long as the R’s stay down.

[Dragncar]

Shift at 5000 max. I have had heavy TRWs with real heavy Ohio pins for years in a 455. 10.84 last Sunday. Iron heads, pump gas.
I shift at 5200-5400 and go through the traps at 6000. But I have H beams and did some oiling system modifications. Stock pan, done so long ago I don't even remember if it had a baffle or not.
The diaper is a good thing for the track and other racers but I would hate to see another Pontiac block ruined. They are just getting hard to find, good ones. I have a few locals looking at buying my splayed billet cap block and Eagle Ross rotating assembly just because they can not find good cores for a street strip build. Even the 400s are hard to find now with the stroker cranks.
A ex Pontiac racer I know blew the rods out of a 400, then a 455 so hard the rods dented the frame in his 67 GTO. He would not listen to advice and laughed when it happened. I gave him the cold shoulder for awhile because of it. Don't be that guy.
Gives Pontiacs the same lame @$$ reputation at the strip and takes away our now precious PMD blocks.

[Hillard]

Well I just got back from Norwalk. Had a lot of problems at first and didn't make any passes on Friday. My E-bay carb was junk (I know..real surprise), and my alternator was making a lot of noise (pulley was slipping). Long story short...bought a new 1 wire alternator and a new Pro Systems 950 carb at the track. Unfortunately I didn't figure out the charging problem till after the first and only time run today.

Car does not launch very hard, but makes it up some on the big end. 1st pass was 13.63 @ 100, 2nd pass was 13.41. 1st round was 13.41, 2nd round I lifted early but numbers indicated a 13.39. Sunday my time run was 13.41. 1st round I took waaay too much stripe. Dialed a 13.40, had an .036 light to his .150. Tapped the brakes and still went 13.27. Don't know where that came from. Like I said, alternator was replaced right before that run. Maybe it helped the MSD distributor and made that much difference??

So with buying a carb that was built for who knows what, no tuning, never touched the timing from what I set it at initially (36 total), I'm fairly happy. Adam...you might be right, there may be a 12 in it.

[adam woodmancy]

Originally Posted by Hillard

Well I just got back from Norwalk. Had a lot of problems at first and didn't make any passes on Friday. My E-bay carb was junk (I know..real surprise), and my alternator was making a lot of noise (pulley was slipping). Long story short...bought a new 1 wire alternator and a new Pro Systems 950 carb at the track. Unfortunately I didn't figure out the charging problem till after the first and only time run today.

Car does not launch very hard, but makes it up some on the big end. 1st pass was 13.63 @ 100, 2nd pass was 13.41. 1st round was 13.41, 2nd round I lifted early but numbers indicated a 13.39. Sunday my time run was 13.41. 1st round I took waaay too much stripe. Dialed a 13.40, had an .036 light to his .150. Tapped the brakes and still went 13.27. Don't know where that came from. Like I said, alternator was replaced right before that run. Maybe it helped the MSD distributor and made that much difference??

So with buying a carb that was built for who knows what, no tuning, never touched the timing from what I set it at initially (36 total), I'm fairly happy. Adam...you might be right, there may be a 12 in it.

I think so! Sorry bout all the troubles you had, but I’m happy you persevered and got some runs in. I think you’ll find a whole bunch in the carb. It might go 12.70s with a tuned 750 on it. Our motors have a lot in common. I broke mine in on the dyno with a 950 hp carb that came off my buddies 455 Buick with TA stage 2 heads. Then I tried a fresh 750 from my carb man Ken Jones built for my combo. Gained 30 hp and 30 ft lbs at 5500. Also have found out inadvertently that the alternator Drag is worth about .07 in the 1/8 on my car. ( oh **** moment when the staring line guy holds your belt up as your staging and you know you’re gonna haft kill a bunch lol) Happy for ya sir.. looking forward to watching you race and progress.