Pseudo racing engine surprise

[rewguy]

any tips on the spring pressures or lifters used?

[Adger Smith]

Randy,
Pretty nice deal. That is real similar to the iron headed IHRA 300 HP crate engine I did. if my memory serves me correctly most of those stock Small Port vortec heads go flat on intake lift at just a little over .510 lift. That .380 intake lobe was getting nearly all the head had with the 1.3 RR @ .490 net lift. That new port work and VJ will make the increased RR shine!
There is another way to tighten the stall. You increased the flow into the converter, now Put a restriction in the cooler line dump (before the cooler or in the loop) Do away with the check valve in the pump body between the cooler in and out. Start with about a .070. This builds pressure in the converter. Back when Comp guys were running PG's I've seen them with a selector plumed in to tune the stall that way.

[randy331]

any tips on the spring pressures or lifters used?

The lifters are Renegade part # 11632-16. The springs are isky part #8005-A. I used just the outer spring originally and they were installed with 150LB seat pressure and 340 open. After the valve train trouble I added the inner to just the intakes and increased the installed height .050". That put the seat at 160lb and open 390lb. I'm a little surprised it need more pressure than what I started out with. The lifters may be part of the issue? I didn't expect it to MPH as good as it has, so I wasn't planning on 7000+ rpm at the finish line. Looking back, I also wish I'd have pulled it out to 7000 rpm with the 1.3s and 1.6 rockers when we had it on the dyno just to know what it does up there.

, now Put a restriction in the cooler line dump (before the cooler or in the loop) Do away with the check valve in the pump body between the cooler in and out. Start with about a .070. This builds pressure in the converter. Back when Comp guys were running PG's I've seen them with a selector plumed in to tune the stall that way.

Wouldn't doing the restrictor in the cooler by-pass restrict the flow to the lube circuit? I may look into doing that at some point, but I want to test my current modifications first. If it works like I think it will, I'll be able to increase converter charge circuit pressure with a switch in the car. I got gauges on the way so I can monitor what my changes do to converter charge pressure, so I can start seeing some stall/down track slip vs pressure relationships with different converters.

Randy

[Adger Smith]

The original circuit is .060 and most trans builders drill them to match the .125 hole in the converter dump that feeds the lube circuit.

[randy331]

Guess I need to learn something. Where is the plowerglide lube circuit restricted to .060"?

Randy

[Adger Smith]

In the front pump. you pull the stator support and there are 3 holes going through that pump half into the area where the stator seats. one of those holes is the dump restriction. I have been told it is there to cushion the converter hit when going from park to reverse or into drive from neutral. Drilling these 3 holes and installing a modified stator support (or drilling it) helps, too.

[ijames]

I know that on a TH400 with it's large input shaft and consequent large effective piston area you have to be careful not to go too high on the converter pressure or you start hurting the crankshaft thrust bearing. Any similar concerns with a Powerglide? If so, what's a safe maximum pressure to measure in the line from trans to trans cooler (converter exit pressure)? Thanks.

[randy331]

I know that on a TH400 with it's large input shaft and consequent large effective piston area you have to be careful not to go too high on the converter pressure or you start hurting the crankshaft thrust bearing. Any similar concerns with a Powerglide? If so, what's a safe maximum pressure to measure in the line from trans to trans cooler (converter exit pressure)? Thanks.

I think it is a similar concern on glides too. The only other one I know measuring converter charge pressure said he's not gone past 120psi and hasn't hurt a thrust bearing unless he damaged a converter. But, he runs a Mopar with a Torqueflite so they maybe different. I got mine back together and adjusted my primary converter charge pressure to #90 low side and #110 on high side. I'm gonna try and get a larger than 20 psi spread from low to high before I test at the track.

The Mopar guy said temp change the charge pressure 30Lbs or so on his and I've seen temp changing mine some from what little I've ran it sittin in the shop, so I'll need to run it more to see how much temp changes it on this set-up.

It'll be interesting to see what changes when it's under full power.

Randy

[ijames]

I didn't know how high you were planning to go, and didn't want you to have a bad surprise if you hadn't looked into it. Lots of guys have killed crankshafts when converting from 200-4R's to TH400's in the Buick turbo v6 world from excessive converter exit pressure. My fuzzy memory says up to about 100 psi is ok on a 200-4R with its smaller input shaft, and 50 or 75 psi is the limit on a TH400. Basically the input shaft diameter equates to a piston diameter trying to push the converter off of the input shaft, and pressure times cross section area of the shaft gives the force pushing on the end of the crankshaft, so what is the diameter of a glide input shaft vs. a TH400 and/or 200-4R? I've never worked with a glide but I thought that I had read (there's that fuzzy memory again ) that a glide and a th400 used the same converter, which is what made me suspicious. Anyway, didn't mean to hijack your thread, good luck with the project.

[wyrmrider]

looked like useful analysis and information not a hijack to me
thanks for the post

[randy331]

So,... at some point Pseudo will get some porting done on the heads/intake.
Been thinking about doing the porting in stages, just to attempt to learn something??

IF, one was going to do that,... how would you decide on what to do first?
Doing it in what order would give the most valuable info?

Would you do valve job only first??
Increase MCSA only first?
Port intake manifold only first?
Port Ex ports only first?

What information would you look at to determine the limit to VE? Or the limit to RPM??

AND,.. most importantly, WHY? would you do it in what order and what would you expect to learn from it??

Randy

[pamotorman]

here is the original head flow numbers I got from GM back in the day.

[englertracing]

Do you have enough carb

If I work out the metric sizes of barrel and choke, that = 43 / 37 mm Is that 1 x 4 barrel ?
When you think that C & D type Jaguars used 3 pair of 45 dcoe webers, I think the chokes varied from circuit to circuit, a guess would be 36 - 39 mm on a 3.8 lt & 4.2 6 cyl
I can't remember the cam timing, but not a lot more if any and max rpm was about 6800

I/R and plenums are different animals

[ItalianJohnny]

I thought you had to cut the Spring Seats and Such on Vortec heads to get a Decent Spring on them ???

[CGT]

I thought you had to cut the Spring Seats and Such on Vortec heads to get a Decent Spring on them ???

They are Bowtie Vortec heads, not production heads. They come with the spring seat work already done.