[65nss4spdGTO]

Originally Posted by napster

Enough with this GARBAGE! Take your arguments to the clubhouse where they belong. Stop screwing up my thread!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I apologize.

As far as the heads, they are fixable. All depends on the direction you want to go and how big the bowls are. First you could have them furnace welded and re-port the heads, would require new seat and guide work. Only company I trust to weld is Midwest Cylinder Head.

If the bowl is larger than 1.93 and smaller than 1.99, you can install larger 2.190” intake valves pending you can shrink the exhaust valve enough for .050” clearance in between. Not sure of the pushrod pinch, but anything you can do to widen that will allow the heads to work better with such a large intake throat, reducing the bulge at the straight wall will help too. I’m assuming the low lift is suffering from such a large bowl area, gaining valve lift could help and a faster ramping cam. Compression is always your friend too. The motor peaks at a very low RPM, power gains from raising peak 200 RPM to 300 RPM will show more power overall.

Calvin Hill
Hill Performance
708-250-7420

[slowbird]

Originally Posted by 65nss4spdGTO

I apologize.

As far as the heads, they are fixable. All depends on the direction you want to go and how big the bowls are. First you could have them furnace welded and re-port the heads, would require new seat and guide work. Only company I trust to weld is Midwest Cylinder Head.

If the bowl is larger than 1.93 and smaller than 1.99, you can install larger 2.190” intake valves pending you can shrink the exhaust valve enough for .050” clearance in between. Not sure of the pushrod pinch, but anything you can do to widen that will allow the heads to work better with such a large intake throat, reducing the bulge at the straight wall will help too. I’m assuming the low lift is suffering from such a large bowl area, gaining valve lift could help and a faster ramping cam. Compression is always your friend too. The motor peaks at a very low RPM, power gains from raising peak 200 RPM to 300 RPM will show more power overall.

Calvin Hill
Hill Performance
708-250-7420

The tightest you go between valves is .050?

[65nss4spdGTO]

No.

And a cam lobe over .500” is also doable, but this is a street engine.

C

[Dragncar]

Originally Posted by 65nss4spdGTO

Don’t distract.

Since you brought up SD doing heads for me, you are saying here in an open forum this is true? Did Dave tell you that?

You know nothing about Mondello’s.

You are also bad for the Pontiac community always spouting off opinions and misinformation without first hand knowledge of any of it.

How many sets of heads have you ported?

One last thing, when your parts and engine build were being held hostage in WI and you’ve were looking for help, that’s right I offered assistance, GFY.

You are nothing but a tool bag.

Calvin Hill
Hill Performance
708-250-7420

p.s. how’s that bad ass build coming along?

Look fellas, the OP is right. Take it to the Clubhouse. I have been on 12+ hours a day lately. Working to 5AM, sleep by 6, get up by 11:30 and back to work at 3PM.
I have a LOT more to worry about. 60 people are depending on me to have the mill ready to roll. I will get back to you guys there, have not checked since last post. I am sure the usual suspects are taking their shots and maybe a few more guys too . I can take it.
And I did appreciate the offer to check on Dan way back then. Things went bad between you and me on CV-1 threads but the Street Section is no place for that talk. I come here to get away from Race Section BS.
"bad ass build coming along". Which one ? 700HPish 461 will be running by April I hope. 540 is still in the works.

OP, I apologize. BTW, stick a bigger cam in it and you will love it. HOs rock on the street.

[slowbird]

Originally Posted by 65nss4spdGTO

No.

And a cam lobe over .500” is also doable, but this is a street engine.

C

Ok, just asking. .050 seemed like a lot, i was confused

[steve25]

I agree with post 61.
I have saved many a mis ported head ( not only Pontiac ) that way and even a custom 2.14" valve might make things way better and those fit without going over to a smaller Exh valve + for just flow testing usage you can get them off the shelf in a Mopar 2.14" valve with the needed 11/32" valve stem.

Also the SD455 heads do not have a great Exh port short turn do high lift flow is limited even as compared to a fully reworked iron big valve D port head so only reworking the Intake port to flow no more then 270 cfm@28" is where I would set the limit on a motor with under 11 to 1 compression.

With a 2.19" valve the chamber will definitely need some unshrouding work to make it worthwhile it install that size valve in the first place,but the gain in valve size may be just enough to offset the CC increase of the chamber to have the compression you have stay near the same without milling the head.

[slowbird]

Isn't stock Pontiac valve guide spacing 1.98? If that's correct doing the math there is very little room for larger valves and no way to leave .050 between them.

[Stan Weiss]

Originally Posted by slowbird

Isn't stock Pontiac valve guide spacing 1.98? If that's correct doing the math there is very little room for larger valves and no way to leave .050 between them.

Brian,
I don't know what the stock valve spacing is and all the Pontiac stuff is over in my nephews garage. That said a stock 2.11" intake and 1.77" exhaust will only have 0.40" clearance.with 1.98" spacing.

Stan

[steve25]

I have used 2.14" Intake valves many times while running 1.77" Exh valves with no interference issues when hot.

[PAUL K]

I know 2.125 and 1.80 in an SD-455 head will nip each other on a few cylinders but still make good power.

[Steve C.]

A fwiw.
Indy Cylinder Head is also well known for their excellent cylinder head repair work...

http://indyheads.com/


.

[PAUL K]

Originally Posted by napster

I have to correct something I mentioned before. The numbers are corrected. The best numbers from the dyno session were at 35 degrees. HP 519 @ 5200 rpm and Torque 578 @ 4200. The following attachment is the dyno sheet I could get hold of, but it is at 36 degrees of timmimg. It will be suitable for discussion purposes.

The intended use of the engine is for street only. It will not be raced. Cliff is right on with his comments. I may have the cam changed at some point if I feel it is necessary. It would have been nice if I listened to my engine builder in the first place, but this is the only time I haven't. I will live with my decision for awhile. We will see what happens when it is in the car.

Originally Posted by napster

Enough with this GARBAGE! Take your arguments to the clubhouse where they belong. Stop screwing up my thread!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Please excuse the interruption but PY has a Troll that needs to be dealt with.

In regards to your post;

Your results are close to typical for most 4.5 inch stroke stock block builds we get phone calls about with the same complaint. I highly doubt your heads are causing a lot of power loss with your combination. You have enough power and torque to have a fun engine to drive. A few minor realistic things you can do to make your engine perform better;

Make sure the cam is installed between 110-113 ICL.

Make sure your valve springs have at least 150lbs. seat and 400lbs. open pressure

Replace the RPM intake with a Torker II or Tomahawk manifold with at least a one inch spacer.

Replace the 1.65 exhaust rocker arm with a 1.5

[slowbird]

Originally Posted by PAUL K

I know 2.125 and 1.80 in an SD-455 head will nip each other on a few cylinders but still make good power.

If 1.98 is right for guide spacing then there is around .017 clearance between valves with those sizes. So i can see a little nipping happening

[mchell]

“Replace the 1.65 exhaust rocker arm with a 1.5”

Curious, are you seeing gains by doing this with higher flowing heads as well?

[Mike Davis]

Originally Posted by mchell

“Replace the 1.65 exhaust rocker arm with a 1.5”

Curious, are you seeing gains by doing this with higher flowing heads as well?

On ported or more efficient heads the split profile cams don't work as well. I swapped my exhaust rocker from a 1.65 to a 1.6 as well as loosening the lash .005 on the exhaust and picked up .10 in the 1/4.

[slowbird]

Originally Posted by Mike Davis

On ported or more efficient heads the split profile cams don't work as well. I swapped my exhaust rocker from a 1.65 to a 1.6 as well as loosening the lash .005 on the exhaust and picked up .10 in the 1/4.

What were your cam specs when you did those changes?

[Mike Davis]

Originally Posted by slowbird

What were your cam specs when you did those changes?

274/280@ .050
108 LSA/ 106 ICL
.440 Lobe

Old Cam was a
272/276 @ .050
108LSA/ 106 ICL
.440 Lobe and was quicker all the way through the 1/4.

[napster]

First start up since the dyno run. Took two months just to get the drive shaft.
Gnarly.

https://www.youtube.com/watch?v=QVzzzFoUWPg

[rtanner]

Unless your putting it in a locomotive, 570 ft pounds torque, will spin tires till you decide to quit, and with traction run a serious hellcat killing quarter mile, so where’s the disappointment?

[pastry_chef]

Originally Posted by rtanner

Unless your putting it in a locomotive, 570 ft pounds torque, will spin tires till you decide to quit, and with traction run a serious hellcat killing quarter mile, so where’s the disappointment?

I'm seeing mid 11s

Hellcat with drag tires, 10s
https://www.youtube.com/watch?v=bXv0uMc-jW4