Don Terrill’s Speed-Talk

PRH wrote: ↑Tue Oct 13, 2020 4:37 pm

The engine was pulled for another 500 rpm to see that power dropped calmly without hitting the wall

So they pulled it to like 6600?

Hp is dropping off at 6200 and it was pulled to 6500

F-BIRD'88 wrote: ↑Tue Oct 13, 2020 4:09 pm The 12" stock GM converter from a Th350 will show a max stall of 2500 rpm when behind a 454 BBC

Only thing I know is that transmission is a slightly beefed up 4L80

If lighter pushrods were indeed the cure...... that sure would seem to point towards the upper rpm problem being some sort of valvetrain control issue. That’s a good looking curve. I would have pulled it a little higher to see that it didn’t run into the wall right where it’s in the meat of the big...

Guys, thanks for all responses! Unfortunately I could attend today but the dyno guy arranged a pushrod swap to lighter .080" rods and also a bit shorter. The length puzzles me a bit since I'm only using mid lift method for pushrod length checking. However the engine is now running well pumping ...

- Air flow is unfortunately not measured. - EGT unfortunately not measured. - AFR is measured and drops clearly when power drops. does air flow start to drop before power drops? what s the afr before and after it starts to drop? The owner of the engine chose to go to this dyno guy because he's expe...

..Decision today was taken to replace the pushrods, currently .130" wall thickness, with .080" thickness. Maybe they were a little bit heavy for this combo however it was a balancing act together with increasing both seat load and spring rates from recommendations and today we went even f...

We had one with a solid roller do a similar thing years ago, but at 6500. It ended up being the nylon thrust button someone installed got mushroomed right over, and the cam would walk forward at 6500, retarding the timing a bunch. Replaced the nylon with a roller button and reset the thrust clearan...

and the right lobe Imo, that’s where it starts. If the lobe is too fast, it can be a big challenge to figure out a way to have the motor turn higher rpms with “regular” HR lifters and “normal” spring loads. Howards recommend 130 lb at seat and spring rate of 348 lb/in, we're now at ~165 lb at seat ...

Ok, time to follow up. The engine has been sitting over the weekend, today we continued testing. To answer some of the questions, please bare with me if I miss one or two ... - Air flow is unfortunately not measured. - EGT unfortunately not measured. - AFR is measured and drops clearly when power dr...

I had a BBC engine dynoed recently and did experience what seemed to be valve float when the curve went almost straight down at 6200 rpm. Up to 6000 the engine is running fine doing 1.35 hp/cu in. Engine has a .640" lift HR cam around 245°@.050", nothing extreme. Springs are set at 145 lb...

I had a BBC engine dynoed recently and did experience what seemed to be valve float when the curve went almost straight down at 6200 rpm. Up to 6000 the engine is running fine doing 1.35 hp/cu in. Engine has a .640" lift HR cam around 245°@.050", nothing extreme. Springs are set at 145 lb...

I had a BBC engine dynoed recently and did experience what seemed to be valve float when the curve went almost straight down at 6200 rpm. Up to 6000 the engine is running fine doing 1.35 hp/cu in. Engine has a .640" lift HR cam around 245°@.050", nothing extreme. Springs are set at 145 lb ...

Both Sealed Power H880CP (pressed pin) and H1134CP (floating pin) lists as 1.350 Comp height.
I have used the H880's without any issues.

i have some afr ported brodix -2 heads. 225 190. they flow 375 and 305 on the exhaust. the intake stalls at much over 700 lift. these were new in 1990 That's the kind of numbers I'd like to see! Did you have them sent to AFR for porting? Could they use an already existing AFR program on the BB-2 he...

Sorry, it's the BB-2 plus that flow more out of the box starting at a Intake flow level of about 340 if I once again recall right. The stock flow numbers are there on that site, just look for Brodix BB-1 26 deg and in the next column which is CCs it list 280. I'm just back from cc'ing the heads; in...