[Stan Weiss]

When you get to the track. If you can get a 2.25 60 foot time out of it, I see it running a 8.3x at around 93 MPH.

Stan

[scott70]

Originally Posted by "QUICK-SILVER"

Those "Stock manifolds" log or ram air?

And what kind of pipes (size/mandrel/crush) are bolted to and behind them?

1/8th mile info in sig with this engine?

I like it
Clay

It was dynoed with 1.75 headers and ram air manifolds and 2,5 mandrel headpipes. The dyno sheet here was with headers and the cast manifolds lost like 16 hp. Yes that what it did in the 1/8th a few years ago. Im using the RA manifolds on the car now.

[scott70]

Originally Posted by Stan Weiss

When you get to the track. If you can get a 2.25 60 foot time out of it, I see it running a 8.3x at around 93 MPH.

Stan

I would love to see 93 mph,,,,I would be really surprised to gain 6mph from prior to now. I really have to baby it out of the hole with the street tires and the gearing isnt great for taking off. Back in around 2000 I temporarily through in a different iron headed 455 with about the same cam in my gto but with headers and and auto trans and ran 7.4 at 93.

[OCMDGTO]

X10 great iron head street build. You need drag radials or slicks at the track or launching will be crazy inconsistent

[Formulas]

On shift points I was hoping a highly experienced 4 speed drag racer would chime in for absolute clarity from experience to get best ET. because it's not so much the RPM at which you shift at it's also where your at in the torque curve in the next new gear based on RPM drop,

I suspect you want to be at peak torque just after grabbing a new gear but I have never science that out on the track

The RPM drop can be figured out mathematically

[ponjohn]

This is a great combo.

Where did the timing end up?

[scott70]

I believe we tried 30,32 and 34 and 32 total was the best.

[AIR RAM]

Wow... thats one FLAT torque curve!!! Very impressive...

SPEED SAFE, NICK

[Stan Weiss]

The question is what is peak torque and at what RPM? As you can see from a graph of the dyno sheet torque is past its peak when the sheet starts.

Stan

[4zpeed]

Originally Posted by Stan Weiss

The question is what is peak torque and at what RPM? As you can see from a graph of the dyno sheet torque is past its peak when the sheet starts.

Stan

Originally Posted by scott70

On the video It made peak trq was 570 at 3400

From post #3.



Frank

[scott70]

Actually playing back the video in slow motion of the dyno pull and looking at some other dyno pull sheets that were started at 3000 rpms,, peak trq looks like 3100 to 3200 rpms and then takes a couple of ft lb dip and almost recovers to peak trq at 3600 and then slowly drops from there.

[scott70]

Checking with motor warmed up,,my lisle cylinder pressure gauge is showing 177 psi. Don't know how accurate gauge is though.

[DaleO]

Thanks for sharing your combo, jealous here. Would you mind sharing the fuel system?

[Stan Weiss]

Originally Posted by scott70

Checking with motor warmed up,,my lisle cylinder pressure gauge is showing 177 psi. Don't know how accurate gauge is though.

Scott,
With 455 ci with 9.7:1 and a 288 degree intake lobe in @ 108 ICL. That is just what I would want to see for cranking compression psi.

Stan

[Formulajones]

Originally Posted by scott70

Checking with motor warmed up,,my lisle cylinder pressure gauge is showing 177 psi. Don't know how accurate gauge is though.

That's excellent. I've had 100% success with pump gas and cranking compressions in that range. Usually when I have an engine up in the 190-195 range they start getting really finicky on pump gas, especially in the summer time and warmer engine temps.

[scott70]

Good to hear the 177 is about where it should be ! I compared the gauge to the gauge on my air compressor at 120 psi and there was only 2 psi difference so I guess the gauge is accurate.
My fuel system isnt much,,stock 3/8 line , fuel tank and a mechanical carter fuel pump thats been there since the 90's.Years ago with a temporary iron headed 455 and auto trans transplanted it did 11.7 at 115 mph in full street trim with the same fuel system ,,weighing in at 3950 with me in it.. I was probably pushing the limits of that fuel setup.

[DaleO]

Originally Posted by scott70

My fuel system isnt much,,stock 3/8 line , fuel tank and a mechanical carter fuel pump thats been there since the 90's.Years ago with a temporary iron headed 455 and auto trans transplanted it did 11.7 at 115 mph in full street trim with the same fuel system ,,weighing in at 3950 with me in it.. I was probably pushing the limits of that fuel setup.

Cool, thanks for the datapoint. It looks like I'll be fine, I am nowhere near the power you have.

[P@blo]

Looks like another 11 second "truck motor" that really needs aluminum heads to perform.

I plan to somewhat replicate what you have done so well on a 455 so thanks for posting this information. Mantra around here is using Pontiac iron d-port heads have held the community back but I see it as not true for a street car. Race is a different story but a efficient port 455 on the street does not seem like a bad idea at all.

Has your block been zero decked?

[scott70]

When I had the motor freshened I ordered some pistons from Paul K that had a custom CH of 1.50. The pistons that were in it had a 1.47 CH and were around .035 in the hole. So now I'm around .005 in the hole so close to zero deck and didn't cut the block. Figured while in there I'd tighten up the quench...with prior head gasket thickness it was about 063 and now is around 041.

[scott70]

If that was a little lean on the upper rpms could I try a little richer secondary rod?It's a 7040267. I'm not sure at the moment what they are but I see it has a G hanger. Probably the only way to see would be to take it to the track to compare numbers,,,should of tried it when it was on the dyno.

Yeah,,a thread I started over a year ago.