Don Terrill’s Speed-Talk

Have you got pics of the S/Victor plenum porting? They are crap out of the box. Did a B to B on a ported and standard and was worth 39 HP and 35 ft lbs on a 422ci. That cam 290 / 302 @ .050" is too big and your comp is too low as a start.

How about a few more details ? Stock engine in a truck ? Supercharged in a boat ? RPM range. 4.530" bore, 4.375" stroke 4340 scat crank, Dart 325cc heads with minor porting, 822 HP @ 6700, 758 ftlbs @ 5300, pump gas street car. It is internal balance. Freind had it built recently and does give it a...

Any one experienced upper main bearings wearing a lot more than the lowers? This is on a BB Chev Dart block new build. 1 - 4 have excesive wear , # 5 still like new. Clearance 1 - 4 has .00275", # 5 has .0032".

Much appreciated Bill. The CHP12 do only have one hole and they seem to have measurements similar to standard SH616S clevite as they have 3&4 the same, 2&5 the same and 1 on its own. Wonder if the GMP12LT are the same. The bearings in GMP12LT sets have an O/D of 2.120 and they are all the same. Tom...

Much appreciated Bill. The CHP12 do only have one hole and they seem to have measurements similar to standard SH616S clevite as they have 3&4 the same, 2&5 the same and 1 on its own. Wonder if the GMP12LT are the same.

Thanks Bill, are the Dart 32210030 a direct replacement to the Durabond CHP12 ?

World BBC Merlin III block takes Durabond GMP12 cam bearings to suit 2.120" OD cam bore. What is the difference in the Dart 32210010 bearing set which they use for Dart SBC with BBC cam tunnel. Also whats the difference in the Dart cam bearings for the BBC 32210030 as I think they are also 2.120. Th...

Hey Mike, we got sidetracked off original topic, but all good. Your original cam you recommende was 273 - 283 @ .050" You think that will get 1000HP+? Why do you think GM engineers on the 10004HP pump gas 632ci came up with there deal in HR with 270 / 287 @ .050 and 780 / 782 valve lift. That has 17...

Can't believe that Mike, not 20,000. Well, you can lead a horse to water............... These lifters have 4 pressure-fed oiling ports to the axle. Oil to the rollers isn't a problem. We have multiple sets in circle track engines that are on their 5th season, and those applications are twice as har...

With good lifters, 20,000+ Being a 632ci engine, it's not going to see much time above 6,500rpm. 20,000 miles???? You serious??? What are you running over the nose, 350 - 400 lbs. :roll: Try 800lbs at max lift. Great thing about these big inch Big Blocks, they need a lot of duration, and don't turn...

Pro Power Engines , I dont think time frame realy cuts it for how long the lifters last, my Isky EZE Max have been in my BBC for 8 years and I run a solid roller with no wear at all.

CamKing wrote: ↑Wed May 04, 2022 9:46 am

bob460 wrote: ↑Tue May 03, 2022 7:56 pm

How many miles will lifters last with them spring pressure's?

With good lifters, 20,000+
Being a 632ci engine, it's not going to see much time above 6,500rpm.

20,000 miles???? You serious??? What are you running over the nose, 350 - 400 lbs.

bob460 wrote: ↑Tue May 03, 2022 7:56 pm

CamKing wrote: ↑Tue May 03, 2022 9:46 am
They're not real aggressive, but how mild can a .500" lobe be ?
You would need 275-300# on the seat, and 780-830 @ Max lift.

How many miles will lifters last with them spring pressure's?

I would think you would get between 2000-2500 miles with needles at best, maby if your lucky

bob460 wrote: ↑Mon May 02, 2022 11:41 pm This one peak's at 6400rpm on pump gas and 10.75 comp!!

https://www.shafiroff.com/chevy-pump-ga ... d-sr20.php

I believe everything I read on the net. Never the less they dont give out anything on the cam anyway.

I would recommend a 273/283@.050", .500"/.485" Lobe Lift, 115 LSA The reason for the longer exhaust durations, is that with an over-square 2-valve engine, you don't have enough exhaust valve area, so you need to add duration to evacuate the cylinder. Yeah, this is pretty close to what I'd use, I'm ...