[Stan Weiss]

Originally Posted by steve25

I estimate like 740 to 750 it would seem, I have no clue what level of torque it put out, but it would lift the front wheels 1.5 ft off the track until we lowered the wheely bar’s.

Note that once the heads where fitted with the larger valves that the motor was dead on 14.5 to 1 compression.

For the mph in the 1/4 I will check with my friend,
This was in a 67 GTO so the frontal area was not that of a first gen FB.

Steve,
Can you also find out what his 60 foot time was?

Stan

[steve25]

Stan he had a best of 1.32.

[Stan Weiss]

Steve,
Thanks. There are a lot of variables I have to guess at to simulate a 1/4 mile run. So these are just guesses on my part. To run 9.13 @ 3300 with your 740 to 750 HP I get he would need a better 60 foot time than his 1.32. This time slip was done using 770 HP.

60 Foot ET = 1.3247
330 Foot ET = 3.7181
1/8 Mile ET = 5.7885
1/8 Mile MPH = 118.1378
1000 Foot ET = 7.5952
1/4 Mile ET = 9.1330
1/4 Mile MPH = 146.7881

Stan

[BLANK1]

slowbird,
Yes, KRE did the valve job. I did switch from Trend 3/8 .080 wall to 3/8 .135 pushrods. Didn't make a difference.

[pastry_chef]

Originally Posted by BLANK1

Would a more aggressive lobed cam help any?

Darby's Jones cam was almost the same, he often ran 10.0 with his Eheads - his car was a bit lighter.

I'd be thinking if your trans is healthy.. converter crappy?
Benefit to head or intake work maybe.. checkeredflagmachine.net - what would they suggest... if they looked at both heads and intake with the goal of ET improvement.

60 foot needs to improve.

[Dragncar]

Blanks issues were talked to death in a closed thread in the Race section. Biggest problem are the 60 foots. The High Ports, unless you need to make the changes to realize the difference you are spitting in the wind.
The same came, converter, gears were used with a larger cc port, longer raised port. Opening them up to 2.4 while the rest of the port not being properly ported by a professional was a mistake.
I have the same exact heads, milled the same with a 2.32 port opening, virtually stock , same valve sizes that will flow more than his heads and there are reasons I had SD finish them vs KRE. Port matching your heads, just opening them up is always a mistake.
Needs a real converter, 5500 and 4.10s. And still the low 10s he wants will be tough. And it will not be very streetable.
He would have been better off doing a engine like in slowbirds thread on the 488. Kept E heads, bought 4.5 crank and pistons. He had better heads, more cam than that 488 engine and he would not have had to change cam, converter and gears. The money spent on the High Ports would have done that.
You are never, ever going to make a 3800lb car ET with 1.58 60 foots unless you have boost. With the 4.5 arm he would have had 650+ HP and 640lbs tq and low 10s were there with his stuff.

OPs question, stick the biggest valve you can in it. The area next to the cyl wall does not flow much no matter the size of the valve. If the 2/3s of the rest of the valve are larger it will flow more. But with the cam he is using 2.11 in fine, does not matter.

[Stan Weiss]

Originally Posted by Dragncar

Blanks issues were talked to death in a closed thread in the Race section. Biggest problem are the 60 foots. The High Ports, unless you need to make the changes to realize the difference you are spitting in the wind.
The same came, converter, gears were used with a larger cc port, longer raised port. Opening them up to 2.4 while the rest of the port not being properly ported by a professional was a mistake.
I have the same exact heads, milled the same with a 2.32 port opening, virtually stock , same valve sizes that will flow more than his heads and there are reasons I had SD finish them vs KRE. Port matching your heads, just opening them up is always a mistake.
Needs a real converter, 5500 and 4.10s. And still the low 10s he wants will be tough. And it will not be very streetable.
He would have been better off doing a engine like in slowbirds thread on the 488. Kept E heads, bought 4.5 crank and pistons. He had better heads, more cam than that 488 engine and he would not have had to change cam, converter and gears. The money spent on the High Ports would have done that.
You are never, ever going to make a 3800lb car ET with 1.58 60 foots unless you have boost. With the 4.5 arm he would have had 650+ HP and 640lbs tq and low 10s were there with his stuff.

OPs question, stick the biggest valve you can in it. The area next to the cyl wall does not flow much no matter the size of the valve. If the 2/3s of the rest of the valve are larger it will flow more. But with the cam he is using 2.11 in fine, does not matter.

Since you seen to know what is going on. Why don't you tell us just what changes to his cam he should have made?

Stan

[Mike Davis]

Bret, a few things come to mind.
Timing? What have you tried/confirmed?
Valve lash? Have you tried loosening up the exhaust lash some? or a different Ex rocker?
What type fuel are you running?

[BLANK1]

Mike,
Haven't tried many timing changes recently. Have kept lash at .015/.019 what the cam card says. Only have tried 1.6 rockers. Have a set of 1.72 Comp Gold rockers but I have to grind on the rocker bodies to keep the pushrods from hitting the rockers at max lift. Have some 1.65 Harland Sharps but couldn't get the geometry good with them. Using Scorpions now. Had to clearance the Scorpions for pushrod clearance. I noticed after Norwalk my pinion angle was under 1 degree. I changed it to 3 degrees down but never made it back to the track. Don't know the effect that has on 60 ft's. Sorry again to OP for hijacking. Will stop if you want me too.

[PAUL K]

Wow just about five pages and the OP's question was answered with post #2

As far as street cars go, 60ft is not comparable to a race car's 60ft. A true street car is going to launch soft. ALSO a heavy car
car can ET well with a soft 60 ft. naturally aspirated. I posted two time slips from my 3900 lbs. street car and attached a video. The 10.30 pass was when the car was powered by a factory block 446 cid using a 2.135 intake valve. The 10.11 pass was a stock block pump gas 469 engine using a 2.15 intake valve. If you watch the video you will notice once the car gets going the engine winds up like crazy. I've had folks claim I was spraying the car at that point.

https://fb.watch/a8b2hMmW52/


Makes one wonder how fast they might go with 2.19 valves, or better yet a 2.25

[BLANK1]

Paul K,
What RPM's did you shift at? My car isn't even close to 135 mph. Best has been 123.85 mph. My motor only has studded two bolt mains. Reason why I'm afraid to spin it up past 6500.

[Mike Davis]

Paul, that 135 MPH is in 9 second territory. What gear? My car leaves rather soft for a 3750lb car with 1.37 avg 60ft. I hate racing cars like the one on the slip because they are coming on hard at the top end and are hard to judge at the stripe.

Bret, I would check fuel system, ignition out thoroughly etc. Amazing how much those have can hurt or help you.
I picked up almost 2 tenths with just fuel pressure regulator, coil and plug wire change.

[PAUL K]

Originally Posted by BLANK1

Paul K,
What RPM's did you shift at? My car isn't even close to 135 mph. Best has been 123.85 mph. My motor only has studded two bolt mains. Reason why I'm afraid to spin it up past 6500.

Around 6800

[PAUL K]

Originally Posted by Mike Davis

Paul, that 135 MPH is in 9 second territory. What gear? My car leaves rather soft for a 3750lb car with 1.37 avg 60ft. I hate racing cars like the one on the slip because they are coming on hard at the top end and are hard to judge at the stripe.

Bret, I would check fuel system, ignition out thoroughly etc. Amazing how much those have can hurt or help you.
I picked up almost 2 tenths with just fuel pressure regulator, coil and plug wire change.

Hi Mike, 3.90 gear. Take a closer look at the second time slip. I think that's exactly what your talking about. We got out sixty footed by a lot, close at the 660 and way out in front at the finish. Your car is heavy also, so as you know harder to get moving but comes on strong once it's rolling. I think your car runs excellent and glad your representing Pontiac at the races. 😎

[Mike Davis]

Originally Posted by PAUL K

Hi Mike, 3.90 gear. Take a closer look at the second time slip. I think that's exactly what your talking about. We got out sixty footed by a lot, close at the 660 and way out in front at the finish. Your car is heavy also, so as you know harder to get moving but comes on strong once it's rolling. I think your car runs excellent and glad your representing Pontiac at the races. ��

Thanks Paul, 3.90 gear seems to work really well in these heavy cars. Stock block shifting a 7200 seems to work well.
Started out last year after the 1st 3 NMCA races number 1 in points with Final round (runner up) appearance in 2 races and then slipped to #2 and stayed about 1 round out of 1st place through the year, got Covid and Pneumonia in August and missed a race so I finished 4th for the year. Hopefully next year I can pull off another Championship....In Nostalgia Super Stock I am drowning in a sea of Mopars. At Indy there was 78 cars in the class and only 3 Pontiacs, 5 Chevys, 1 Buick and a few Fords.

[Dragncar]

Originally Posted by Stan Weiss

Since you seen to know what is going on. Why don't you tell us just what changes to his cam he should have made?

Stan

I already have, does not matter. The cam I am running would work well. But unless you change other things and difference will be small. Lash will not change much. Fuel system could help if his is not up to par.
His engine should have a good top end pull as is, just have to get it to 60' and I bet he gains 4-5 MPH.
The changes needed to make the car 60' might make it un streetable. Its all in what you want.
A big time tq engine would have worked well IMO. But I would not throw a 4.5" arm in a 2 bolt block either.
He is kind of caught in the middle at this point. But no reason he can not get down to mid 10s either.

[slowbird]

Originally Posted by Dragncar

I already have, does not matter. The cam I am running would work well. But unless you change other things and difference will be small. Lash will not change much. Fuel system could help if his is not up to par.
His engine should have a good top end pull as is, just have to get it to 60' and I bet he gains 4-5 MPH.
The changes needed to make the car 60' might make it un streetable. Its all in what you want.
A big time tq engine would have worked well IMO. But I would not throw a 4.5" arm in a 2 bolt block either.
He is kind of caught in the middle at this point. But no reason he can not get down to mid 10s either.

Am i reading this right, you think by improving 60fts the car will gain 4-5mph?

[PAUL K]

Originally Posted by Stan Weiss

Since you seen to know what is going on. Why don't you tell us just what changes to his cam he should have made?

Stan

I recently built a Hi-port factory block engine (around 460 cid) that made about 750 HP. It used a similar cam to Blanks. I sure wish we would've had that secret spec'd, pump gas cam that would've put us over 800.

[Dragncar]

Originally Posted by slowbird

Am i reading this right, you think by improving 60fts the car will gain 4-5mph?

In a way, yes. He needs to do more than one thing to get that thing to 60'. Say does does it and gets 1.40 60 foots, doable. I can get 1.42-1.43 out of a POS 9-1 iron headed TRW junk heap with a 850 DP, and he has a 11.3-1CR High Port with 1050 with better intake. He should be making 100 more HP than I do with about 200lbs more weight.
It takes 647HP to get 3800lbs to 10.50 and 607 HP to get to 127 mph.
If you go from a 1.56 60' down to a 1.40 60' I would say 3-4 mph, maybe 5 mph. You have to get that weight moving so the engine can have a chance at crossing the line 200RPM past peak HP.
IMO the biggest difference would be a real converter, 1200$ worth. But then again it would not be very streetable.
No free lunches. More cubes and tq and he would have a shot at low 10s pump gas power with his setup.

[Dragncar]

Originally Posted by PAUL K

I recently built a Hi-port factory block engine (around 460 cid) that made about 750 HP. It used a similar cam to Blanks. I sure wish we would've had that secret spec'd, pump gas cam that would've put us over 800.

I asked you about that engine awhile back and you did not respond.
Is that a 750 HP true pump gas 461 stroker ? If it is that would make you top dog. I do not know of any higher.
Lets see the dyno sheet, please.