[Skip Fix]

Got off the dyno with a 400 built with the plan of mainly extra parts laying around for the 65 GTO stick car so it moves on its own in place of the barely running original 389 4BBL.

Short block the 0.0303 400 557 block I had under the RAIV heads racing NMCA for years. TRW 2262s/pressed pin Crower billet rods. Clean up hone and tanked. Had to turn crank 0.020 to get some bearing close in clearances and not too loose . Still about 0.0028-0.003 mains and rods. 5/64 rings for the TRWs limit choices. Standard 0.030 Sealed power "drop in" were 0.028 top ting and 0.020 second ring. File to fits were way too much tension so went with the first set. one piston was 0.008 out another 0.005 so went with the thicker regular Butler head gaskets-added the "421 hole".

Heads some new "72" cc E heads Paul Knappen cleaned up , clearances for 1.65 rockers. Original "bathtub" chambers. Paul used the Comp 917 springs Polydyun coated I had bought years ago for my first E heads(on the IA now but were on the roller 455 years ago) they were tight on those pockets so those heads got some Lunati 1.500 springs). 1.65 Crower SS rockers I picked up here years ago. 9.300 Comp 5.16 pushrods.

Comp solid rollers I had ton the roller 455 years ago-non pin oiled. UD/Bullet solid roller from the .3707 lobe family to use the high ratio rockers. 242/249@ 0.050 112 LS 108 IC. Felt the 259/264 .3707 for the 455 would be too rowdy in a 400 even being a stick. Tim at Bullet and I talked a awhile and he agreed with my choice.

Intake an older Performer RPM I lended to Lee year ago to try on his Firebird vas a T2. Cut out the exhaust crossover and front part to water crossover to look like a tal HO intake. Ground off Edelbrock and bead blasted it.

Oil pan deep Moroso GTO pan that came with the 455 when I bought it. Braces and teflon coated full length factory windage tray originally on the RAIV motor.

Carbs to try:
1)HP 950 off the recent 455 Stump Puller since I new it worked. 83/89 jets
2)HP 750 body and new 750 DP metering blocks, bowls and baseplate I had extra 72/81 jets(out of 80s)
3) Demon that started out as an 850 Jeff "Shaker 455" machined for the demon changeable sleeves. Was run on the IA motor years ago with big sleeves I put in the "Red" ones between a 750 and a 850/950/1000(all the same size really) I must have tweaked something pulling the baseplate off and on for them as we could not get it to idle at all and gave up on it.
4) 73 SD SR Qjet first massged by Brad Urban with larger primary blades and replaceable secondly jets Then Cliff went through it a few years back. 71 rods/44 jets and DA secondary rods on a B hanger.

Headers -my trusty 2" Hooker 4202s and the tribal Tubes 1 3/4-1/78 tri Ys. Had some OBX 1 7/8 but just did not try them.

Weather cool and overcast for Houston summer high humidity and started drizzling mid day.

The RobbcMc starter used on the 455 did not sounds right -probably just needed shimming but threw on and extra McLeod but had to trim the pan rail for it some clearance where the bolts stick out.

results 950 HP Best TQ 478 @4100 HP 484 @5900 kind of fat BSFC.
750 HP TQ 477 @3800 HP 470 @6100
Qjet TQ 476 @4000,4400,4600 HP 474.9 @5800

Tri Y Qjet TQ 479 @4200-4300 HP467 @6000 and a 114% VE @4000. We only had the VE hat on for the Q jet pulls.

Best thing was no oil leaks!!!

[Skip Fix]

First graph was the 950 vs 750 . I could not find how to change colors for different runs.
Then Q jet with 2" then Tri Ys

[steve25]

Thanks for the results!
There good numbers for pistons with 5/64” top and second ring package, as I am sure they where eating up at least 15 hp above 5k rpm.

Do you have any of the average torque and hp numbers you could share from those dyno test?

[Half-Inch Stud]

Q-JET and Tri-Ys for the Sig Digits Street win.

[Skip Fix]

Steve I'll look tonight if I can figure out how to do that. I tried a bunch to figure in WinDyn how to change colors for the different test to see them better but could not.

[PAUL K]

Great job Skip!

Almost 1.2 HP/CID is getting it.

Interesting results on the testing. Thanks for sharing

[grivera]

Great numbers - big cojones with the 557 block!

[Skip Fix]

I figured it was sitting there(the short block) so what the heck! and a 400 will hit softer with a stick than a 428 or 455! And I have a 33 spline 12 bolt ready also.

I think Tom S has a 557 block dyno mule that has seen 500 HP+

[steve25]

A 500 hp motor set up with a correct tune is under less stress block wise then 350 hp motor that’s detonating!

[tom s]

My 557 engine was just a skosh short of 600.Tom

[Skip Fix]

This one may end up with the Bathtub if it will fit under a GTO Hood!

[Skip Fix]

Averages
1) 950 HP TQ 446 HP 437
2)750 HP TQ 442 HP 416
3) Qjet TQ 444 HP 421
4)Qjet Tri Y TQ 440 HP 411

[P@blo]

Looks like I need more 557 blocks so I can make 600+ish? Slap it togeher and Ricky Bobby it? Common man, give some details...

[70GS455]

My Qjet hated the hat (turbine). If we used the bigger one and taped it to the air cleaner base without the reducer it did better but still killed some hp. Using the O2 sensors was better for me

[70GS455]

Originally Posted by Skip Fix

Steve I'll look tonight if I can figure out how to do that. I tried a bunch to figure in WinDyn how to change colors for the different test to see them better but could not.

F12 changes colors

[Skip Fix]

Thanks. I'll try it. I can change colors on the parameters already up but then when I go to overlay it does not on the new test.

My Q jet did not have the choke so turbine fit OK. They don't have an O2 sensor . One motor a few years ago I brought my LM1 but it was a pain to coordinate on it and the pull. I think we had battery issues that time also.

[tom s]

585 HP and 601 TQ with the Bathtub and a pair of 750 NASCAR AFBs.455 CI.The thread is still on this site.Tom

[mchell]

Originally Posted by Skip Fix

Got off the dyno with a 400 built with the plan of mainly extra parts laying around for the 65 GTO stick car so it moves on its own in place of the barely running original 389 4BBL.

So what was your final Cubes and compression ratio?

[Skip Fix]

40002 950
40004 750
40007 Q jet
All with 2" headers
0.030 4400 4.151 3.75 stroke. Average deck pr0bably 0.003 out assume a 75cc chamber for a "72" cc E head 10.1 CR

[Skip Fix]

Here is Qjet with 2"(red) vs Tri Y 4008 Bluedifferent colors so easier to read.