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6800 rpm 421 SBC Combo

General engine tech -- Drag Racing to Circle Track

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Orr89rocz
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Re: 6800 rpm 421 SBC Combo

Post by Orr89rocz »

BLOCKMAN wrote: Wed Jan 08, 2020 1:16 pm
77cruiser wrote: Wed Jan 08, 2020 12:55 pm Eric & Chad both sell fully ported Profilers. I have a set that I got from Eric, nice heads but the D port Ex. makes header fitting a pain.
Check with Tom @ 3V Performance as Tom CNC machines his heads all in house Chad farms all his CNC work out BIG differance LOL

https://3vperformance.com/
Nothing wrong with that. Chad hand ports everything to develop the port then has it digitized and cnc profiles made. The heads work
n2omike
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Re: 6800 rpm 421 SBC Combo

Post by n2omike »

BLOCKMAN wrote: Wed Jan 08, 2020 1:16 pm
Check with Tom @ 3V Performance as Tom CNC machines his heads all in house Chad farms all his CNC work out BIG differance LOL

https://3vperformance.com/
Thanks... I clicked on the link, and the only heads I saw that he offered were Dart. I'm not a Chevy guy, so unless ProFiler uses a Dart casting, I don't see anything.
trmnatr wrote: I adjust them to zero lash just like a solid roller lifter, one cylinder at a time then fire it up and adjust them running. I have tall and short valve covers cut out. Adjust them with your fingers on the rocker body and as you loosen it you will feel it then hear it, tighten down adjustment nut slowly until you feel zero bumping in the rocker body = zero lash, then I tighten the adjuster from 12 O’clock to about 1:00 to 1:30 listening to the motor and lock it down
Thanks for the tip on adjusting HR lifters to keep them from floating. I assumed as much to keep them from floating... I guess they don't collapse too much with spring pressure and rpm? I did see some Johnson Short Travel HR lifters for SBC at the 3V site (sold out) for $510. I guess these are an attempt to be the best of both worlds.

Do you guys see much difference in power on similar engines with Hydraulic vs. Solid Roller lifters?
I'm on the fence, as I've always used solid lifters.

Thanks!
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67RS502
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Re: 6800 rpm 421 SBC Combo

Post by 67RS502 »

I did Johnson lifters on my last SBC, only on the dyno, but they are quiet.
If youre considering doing a HR, buy quality lifters, .135” P-rods, and spring pressure minimum 180/450,
and it should turn 7000 with not too aggressive of a lobe.
Preload ¼ turn minimum, but 1 turn is good.
Use correct oil for breakin.
If using different lifter types on the same lobe the HR lifter will make more power, (with a stable valvetrain),
since the SR lifter needs lash. You would have to add some duration to make up the diff, so 2 different cams are needed to compare.
Stick with a quality valvetrain on an HR and it will rev and make power on a street deal over 7000.
Watch the P-rod pinch on the afrs or do the profilers, but heads (and intake) need to be done by someone competent.
67 camaro
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
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