440 w/TorqStorm SC - Boost Getting Into Crankcase?? Valley Pan BULGE

[yellow rose]

@yellow rose the blow through in this application will be the best case scenario. The latent heat of vaporization will give him an intercooling effect. It will be significant up to the point that the blower becomes inefficient. Which, with a torquestorm on 440 inches is a small window. I would say he’s pretty safe up to about 8lbs of boost. And it should have a rising boost curve through peak torque so he may only see 3-4 psi at that point. Anything more than that IMO this thing will stop making boost and become a giant heat pump and all the things you’re talking about will ring true. We need much more info from the op on machine work and set up. And what it took to get to his power level. We have no idea if he’s at 10:1.

All true. My point about the blow through carb is the narrow tune up window and limited tuning capabilities.

If he is at 10:1 he is treading on slick ground. Like I said...I don’t have the balls to do that on pump gas. At least not at my age now.

 

[RustyRatRod]

That’s true...we have no way of knowing what level of machining was done. I always hope that the machinist keeps up with current technology. It’s moving so fast right now (ring tech, oil tech and even piston skirt finish) that what was top of the mark 5 years ago is just passable today.

The other thing I forgot to mention is the high compression with no way to cool the inlet air is a recipe for serious detonation. The OP could be running into enough detonation it’s upsetting ring seal and that’s where the combustion pressure is coming from.

You know as well as I do how critical engine temp and inlet air temp is when running higher than orthodox compression ratios on pump gas.

The tune up window gets substantially smaller as the CR goes up. And what would be a small tuning error with a lower CR becomes a huge error with that CR and boost.

I agree with you 100%.....but the unfortunate fact is, a lot of machinists don't keep up with what is modern, PLUS a lot and I mean a LOT of machine shop customers don't give a **** and only want what's cheapest....not saying that's the case with the OP, just making an accurate statement. Thirdly, some machine shops will argue with you when you tell them how YOU want something done. That's when I move one. The one I am currently using is owned by a grumpy old fart older and grumpier than I am and he does it just like I ask.

 

[table30]

The LS engine guys running turbos all usually use crank case vents plumbed to puke tanks on their racing engines. I think it is pretty common to have some positive pressure in the crank case when hammering on a boosted engine. Those guys have a lot of aftermarket support made for dealing with this kind of application - maybe poke around on their forums to see if you can pick up some info.

Great advice....and I had already landed there before this post. The catch can with breather looks interesting. Maybe one for each bank?

Kevko K9085 Remote Breather Tank, with 1-1/2 Inch Filter

 

[table30]

@yellow rose the blow through in this application will be the best case scenario. The latent heat of vaporization will give him an intercooling effect. It will be significant up to the point that the blower becomes inefficient. Which, with a torquestorm on 440 inches is a small window. I would say he’s pretty safe up to about 8lbs of boost. And it should have a rising boost curve through peak torque so he may only see 3-4 psi at that point. Anything more than that IMO this thing will stop making boost and become a giant heat pump and all the things you’re talking about will ring true. We need much more info from the op on machine work and set up. And what it took to get to his power level. We have no idea if he’s at 10:1.

As far as I know, the static compression was at 10:1 when the engine was on the dyno. The re-re-build is underway now to reduce that to 8.5:1. And yes, I chose the blow-thru setup because I didn't want to plumb an intercooler for this car. And yes this was intended for pump gas. As I stated in the original post, I had questioned the engine builder on why he went with higher compression. He basically said 'it's done that way all the time'....problem is I think it is done on more modern engines with precise EFI control. The conventional wisdom (as I have always understood it) is that you want to start a boosted build with lower compression, esp. if it's an engine from 1974

 

[table30]

I agree with you 100%.....but the unfortunate fact is, a lot of machinists don't keep up with what is modern, PLUS a lot and I mean a LOT of machine shop customers don't give a **** and only want what's cheapest....not saying that's the case with the OP, just making an accurate statement. Thirdly, some machine shops will argue with you when you tell them how YOU want something done. That's when I move one. The one I am currently using is owned by a grumpy old fart older and grumpier than I am and he does it just like I ask.

The block was bored .030 over with a torque plate, line honed and decked. 1974 RB smogger.

 

[RustyRatRod]

The block was bored .030 over with a torque plate, line honed and decked. 1974 RB smogger.

Then you may well simply have too much static compression with a blower. I didn't read word for word the whole thread, but I didn't see how much boost? With that much compression it doesn't need to be much to over come ring seal. Just one opinion of course.

 

[table30]

Then you may well simply have too much static compression with a blower. I didn't read word for word the whole thread, but I didn't see how much boost? With that much compression it doesn't need to be much to over come ring seal. Just one opinion of course.

I don't think a Torque Storm can produce anything over 5-6 lbs without pulley mods.

 

[RustyRatRod]

I don't think a Torque Storm can produce anything over 5-6 lbs without pulley mods.

But you have over 10:1 static compression. That's a lot for a forced induction engine.

 

[RAMM]

I don't think a Torque Storm can produce anything over 5-6 lbs without pulley mods.

This thread is of particular interest for me--just finished testing a 461BBC Marine with a TQ-Storm and Sniper EFI/Hyper-Spark Distributor. I didn't build it or sell one part for it--just tested it. I was surprised when it produced 6psi @ 5500 rpm too considering the large 360cc rectangle port heads and Brodix single plane intake. Power was nothing to write home about but the compression ratio was supposed to be 7.5-1 and I have no reason to disbelieve that.

Have you physically looked at the pistons? An engine can still leakdown and compression test fine with missing ring lands--I've done it and seen it. If all of your pistons tops are intact then maybe you are experiencing cylinder wall distortion under load? I saw another poster ask about the dipstick not blowing out--Did it? If so-I understand If not--I don't understand why it wouldn't. J.Rob

 

[table30]

This thread is of particular interest for me--just finished testing a 461BBC Marine with a TQ-Storm and Sniper EFI/Hyper-Spark Distributor. I didn't build it or sell one part for it--just tested it. I was surprised when it produced 6psi @ 5500 rpm too considering the large 360cc rectangle port heads and Brodix single plane intake. Power was nothing to write home about but the compression ratio was supposed to be 7.5-1 and I have no reason to disbelieve that.

Have you physically looked at the pistons? An engine can still leakdown and compression test fine with missing ring lands--I've done it and seen it. If all of your pistons tops are intact then maybe you are experiencing cylinder wall distortion under load? I saw another poster ask about the dipstick not blowing out--Did it? If so-I understand If not--I don't understand why it wouldn't. J.Rob

My engine builder torn the engine back down after the dyno test. He said everything looked normal.

 

[TT5.9mag]

I was surprised when it produced 6psi @ 5500 rpm too considering the large 360cc rectangle port heads and Brodix single plane intake.

As you know @RAMM boost is only a measure of restriction to flow. The combo you tested was likely too efficient to make use of an entry level supercharger like a torque storm.

 

[RAMM]

As you know @RAMM boost is only a measure of restriction to flow. The combo you tested was likely too efficient to make use of an entry level supercharger like a torque storm.

Making 540hp/560tI wouldn't use too efficient I would use big port , high flow, low port speed resulting in lower than expected boost--I figured 3-4 psi max. As I understand it the customer had TQstorm machine the crank pulley a custom size to spin the supercharger at max speeds knowing it is undersized to begin with. J.Rob

 

[TT5.9mag]

Yea efficient was probably the wrong word to use. But 461 inches with 360cc heads and a big single plane even at 7.5:1 I’m gonna guess you’d have to spin the guts out of the torquestorm to get it to make a big boost number. I wonder what a procharger F1 would do on that combo. I just finished an engine very similar for my boat. 468 inch BBC at 9.2:1 with 360cc cnc ported aluminum heads, roller cam, single plane and a blow through CSU 750. It’s getting an F1A-94 over the winter. I’m hoping for 900.

 

[PRH]

just finished testing a 461BBC Marine with a TQ-Storm and Sniper EFI/Hyper-Spark Distributor.......

.........Making 540hp/560t

Wow........that sure sounds like an expensive way to end up with those numbers.