[lhmurphy]

Originally Posted by panhandle

I just finished a 406 in Oct and had it dynoed on an engine dyno. Below are the parts used compression specs.

1978 400 509 block .030 over (406 ci)
Eagle crank 3.750
Scat 5.70 Rods
Probe 22.5 dish pistons (9.6 SCR, 8.3 DCR)
Howards HR Cam, .233/.241 at .050, .530/545 lift, 110 degree LSA
Fel-Pro .041 head gaskets
Trick Flow 23 degree heads, 195 cc runners, 64 cc chambers
Weiand Air Strick intake
Holley 770 Street Avenger
GMPP HEI ignition

Engine dynoed at 474 hp at 5700 rpm and 509 Torque at 4400 rpm

Very streetable engine on pump gas and should have no detination
problems. I'm using 91 octane right now but will try the 87 octane
when spring gets here. Only drawback of the build is the tires seem to
wear must faster.

I ended up goin with a comp 12-433-8 and I'm pretty happy with it...I'm just waiting on a hi torque starter now lol

[panhandle]

I have the dyno sheets but have no idea how to get it to show up on here. I had alot of help selecting the parts for the build from the group at Chevy Talk.

[vinniekq2]

Panhandle,dont worry about it.I was curious about A/F ratio for tuning,was it street tuned or race tuned? The SFC also tells us the efficiency of the engine.If the fuel burn is lower it will also last longer

[panhandle]

This build was done just for the street. I did have him run it up to 6200 to see how the HR cam would behave and it probably never see the RPM again. I do have some readings for BSFC if that is what your looking for, I can copy them over for you.

[vinniekq2]

That would be graet,same with air fuel ratio please.not all,just a few random if its too much trouble

[panhandle]

Here's what I have, hope it's what your looking for.

RPM Fuel/Gal/Hr BSFC

4000 25.13 .419
4100 26.02 .436
4200 26.71 .434
4300 27.31 .433
4400 27.82 .433
4500 28.45 .435
4600 28.94 .436
4700 29.43 .437
4800 29.80 .438
4900 32.49 .474
5000 37.80 .547
5100 43.10 .617
5200 46.20 .656
5300 47.60 .673
5400 48.20 .678
5500 48.50 .678
5600 48.60 .673
5700 48.70 .670
5800 48.70 .669
5900 48.70 .670
6000 48.70 .674

Now that I've copied these down, could you explain them to me?

Thanks

[vinniekq2]

deleted my post 1/2 way through writing,,,,,

[vinniekq2]

at 4400 rpm,you are burnig 43 pounds of fuel(7 gallons per hour) for every 100 horse power your engine makes.

at 6,000 rpm you are burning 67 pounds of fuel per 100 horse power your engine makes. much worse at higher rpm

I see dyno time could net more horse power and better throttle response,and less fuel burn.
sorry I lost the long post,I type slow and my hands hurt

[panhandle]

What else would you recommend?

[vinniekq2]

does your carb have replaceable air bleeds? did you move the timing around?did you do any jet changes? I see a few more pulls with detailed tuning(air bleeds and secondary jets)

[cdminter59]

Originally Posted by lhmurphy

My engine should be done Thursday and I hope to install it right after that and can let u guys know if there is signs of detonation...my machinists says there won't be detonation lol

Has your engine been finished yet? You know you caused all the problems with your thread. If you had took time to read the papers that came with your kit and provided the info in your post none of the arguments would have happened.
I took the time to search Ebay to find your kit. I should not have had to do this. I found all the info I needed to calculate your static compression and DCR. The first thing I did was get your parts stack height. 1.875+6.000+1.140=9.015. 9.025-9.015=.010 for piston to deck clearance. Using these figures your static compression is 10.373 and the DCR is 7.951 which runs on 91 octane gas. You asked for opinions on your build but did not have the information to make a logical opinion. The one major difference is the compression height of your piston versus most brands of 400 pistons which is 1.425. You have good parts and it sounds like this is going to be a powerful engine. Post how it runs when you get it in your car.

[panhandle]

Yes, we ran it through 11 pulls. We started with the shop 750 carb and shop ignition. He twicked the engine with his stuff then we switched to mine and we played with different jets and tried different timings. Looked back on some of the earlier pulls and they show more hp and torque but fuel comsumption was higher on the lower end where I would be driving most of the time. There was quite a bit of difference just between the 33 degree setting and the 34 degree setting. At 38 degrees, the chamber temp was too high so he dropped it down to 33 and then up to 34 where he said that it looked like that where I should run it. There was very little difference between the shop Holley 750 and my 770 Street Avenger Holley.

[lhmurphy]

Originally Posted by cdminter59

Has your engine been finished yet? You know you caused all the problems with your thread. If you had took time to read the papers that came with your kit and provided the info in your post none of the arguments would have happened.
I took the time to search Ebay to find your kit. I should not have had to do this. I found all the info I needed to calculate your static compression and DCR. The first thing I did was get your parts stack height. 1.875+6.000+1.140=9.015. 9.025-9.015=.010 for piston to deck clearance. Using these figures your static compression is 10.373 and the DCR is 7.951 which runs on 91 octane gas. You asked for opinions on your build but did not have the information to make a logical opinion. The one major difference is the compression height of your piston versus most brands of 400 pistons which is 1.425. You have good parts and it sounds like this is going to be a powerful engine. Post how it runs when you get it in your car.

Got it in Saturday and got my timing set and did some carb tuning and road testing and it runs very strong and I'm happy with it...also the build took longer to do bc I got a crankshaft the was machined wrong