TorqStorm Supercharger build advice needed

[Jerry Miller]

Hi. I've been lurking on here for a while, but finally joined. I've searched for some of this but wasn't successful it what I specifically was looking for. So my son is working on a 1983 Dodge W150 pickup with the slant. He's decided to rebuild the engine and install a Torqstorm supercharger kit. I have Doug Dutra's book on order but figured I'd ask a few questions here.
1. For now, I think we are planning to plumb a boost line to the existing mechanical fuel pump's vent hole. I've seen this done before, but any issues I should be aware of? I know an electric pump and regulator would be the hot setup but we're trying to keep it as simple and reliable as possible.
2. Must we run an ignition system with boost reference to retard the timing or can I set the initial timing to ~10 BTDC and then do a lockout plate in the distributor to limit max advance to mid 20's or so? Once again, trying to keep it as simple as possible and honestly the $700 price tag for the MSD box is a bit much now.
3. He has the Carter BBD 2 bbl on a cast iron 2 bbl intake and stock exhaust manifold. He plans to keep the manifolds and maybe convert the BBD for blow through. Though we are looking at the Holley 350 and 500 2 bbls. Would like some input on this from people that have some experience with these.
4. His engine already has the head rebuilt with stock valves and the head is shaved .030" but we are looking at the CompCams High Energy cam package. I think its the 212 duration and .45" lift. He's planning to just run .030 flat top pistons from Sealed Power (cast) which I think will be fine for lower boost levels (input?) and not sure if we should deck the block at all.

This is a daily driver (he's in High School) and is a lifted truck with 35" tires and 4.56 gears with the NP435 4 speed manual. He plans to do some off-roading with it, but basically it needs to be a decent all condition type of engine build. I appreciate any info you guys can share and really appreciate being able to join. Sorry for such a wordy post (especially for the first one!)
Jerry

 

[Charrlie_S]

If you don't get the answers you need on this site, try over at slantsix.org. I know there are a few members over there that have bought that super charger for the slant. I don't know how many have completed an install at this point in time. I think member Dart270 has his running. He is also located in Va.

 

[Jerry Miller]

Thank you for that. I appreciate it!

 

[RustyRatRod]

All I have is this. If you use the lockout plate to limit timing, be very careful and VERIFY whatever slots you use are giving the correct limited timing. I tried one in a slant 6 distributor and even on the smallest slot, I was still getting 14-16 degrees of advance. Whether this is limited to just the slant 6 distributors or not, I don't know, but that was my experience. I ended up removing the plate and welding and filing the slots to end up with 10 degrees advance at the crank, since I run about 20 initial. So be warned. That plate may not limit mechanical advance enough.

 

[TT5.9mag]

You can lock the timing where you want it for max power on boost but it will be wrong for every other driving situation. If you care about drivability and or mileage, you need some kind of timing control to pull timing on boost and still have a decent curve the rest of the time. The MSD6BTM is the simplest way to get there.

MSD 6462 MSD 6-BTM Boost Timing Master

 

[RustyRatRod]

You can lock the timing where you want it for max power on boost but it will be wrong for every other driving situation. If you care about drivability and or mileage, you need some kind of timing control to pull timing on boost and still have a decent curve the rest of the time. The MSD6BTM is the simplest way to get there.

MSD 6462 MSD 6-BTM Boost Timing Master

Splain that to me. Is that an MSD ignition box TOO with the boost retard built in? The way I read it, it's the whole thing, right?

 

[TT5.9mag]

Converting the bbd will be a hassle at best. The Holley two barrel could be done much easier but really I’d look at one of quick fuels 450 4 barrels and convert that to blow through.

Quick Fuel HR-450 HR-Series Carburetor 450CFM

 

[TT5.9mag]

Splain that to me. Is that an MSD ignition box TOO with the boost retard built in? The way I read it, it's the whole thing, right?

Yessir. Just a MSD 6 box with an internal map sensor. And a remote mount rheostat to set the amount of timing pulled per pound of boost. I use one on my boat and it’s flawless.

 

[RustyRatRod]

Yessir. Just a MSD 6 box with an internal map sensor. And a remote mount rheostat to set the amount of timing pulled per pound of boost. I use one on my boat and it’s flawless.

Cool. That will make it a lot easier when I build my blown slant.

 

[TT5.9mag]

Cool. That will make it a lot easier when I build my blown slant.

It really does make it easy. I run 18 initial, 36 total (in pretty quick) and I pull 1 degree per pound on 9 psi on the twin turbo big block in the boat. Starts easy, idles easy, and gets much better cruise fuel economy than if I locked the timing at at 27 degrees.

 

[Jerry Miller]

Thanks guys. I will definitely reconsider the timing situation. How about cam selection and decking the block? Not really sure what the compression ratio should be for a supercharged scenario. It has to be streetable. Very curious what a mild build and the supercharger will look like for hp and torque.

 

[Charrlie_S]

No experience with a super charger, just a turbo. But if I were doing it, I would look at about 8.4 -8.6 CR (measured, and for real), so you have some low speed torque. But with a super charger you will still have some boost at low speed, unlike a turbo where there is almost no boost at low speed cruise.

 

[RustyRatRod]

Normally, blown engines respond more favorably to a wider LSA than a narrow one. Like maybe a 114 instead of a 108. I'm a big proponent of running a low static compression ratio with a blower. That way, you actually USE the blower. If I build one, and I might, I would get the static compression probably right at or even a little under 7:1.

 

[65 Dartman]

. . . . and decking the block?

I happen to be following a machine shop in CO . They recommend taking only enought on the deck AND the head so that they’re flat for best sealing. Likely sny decent machine shop would recommend the same

 

[TT5.9mag]

There are two schools of thought here, more compression and less boost or less compression and more boost. The fuel you use will be the determining factor for ALL of this. Pick that first. On street stuff I prefer more static compression and less boost. That keeps the drivability in a happy spot. I’d aim for 9:1 compression (measured) and keep boost conservative like 6-8psi and it’ll be snappy and make good usable power. Especially if you’re not trying to rotate the earth. I’ve not used a torquestorm but everything I’ve seen/read says they are happy in that 6-10 psi range.

 

[TT5.9mag]

I happen to be following a machine shop in CO . They recommend taking only enought on the deck AND the head so that they’re flat for best sealing. Likely sny decent machine shop would recommend the same

Depends on what you’re trying to do. Basic rebuild? That’s absolutely true.

 

[Jerry Miller]

Looks like we are going to shoot for 9:1 on the compression. So his head already has been shaved .030”. Rough numbers show that .090 off the head is usually around 9:1. Not sure if we should take another .060 off it or just take .060 off the block. Based on the shape of head chambers it looks like either will basically yield the same numbers. This is also assuming the use of a felpro head gasket. Let me know if I’m way off here please.
So 9:1 with 6-8psi of boost. Is this practical with 91 octane fuel or should we leave the head at .030 and not touch deck height?

 

[TT5.9mag]

I would take material off the deck to get your compression number. You’ll have to know what piston you’re using and rod but you mock it up and measure how far down in hole the piston is, then you know what you can cut.

 

[RustyRatRod]

Is this supposed to be a pump gas motor?

 

[Jerry Miller]

Is this supposed to be a pump gas motor?

Yes. I know we went about things backwards. Originally he was just going to have a normally aspirated engine. When he got the truck, it was low on compression in one cylinder and none in another. We popped the head off and found some bad valves. Cylinder walls looked decent. His budget was much lower at the time (and we had body work and a lot of other stuff on the truck going on) So we gambled and just redid the head. He had no intention of forced induction at the time so we figured let's shave the head a bit. I'm glad he didn't do the full .090 that he was originally planning. Anyway, once the truck was back together it became clear that the bottom end, indeed needed attention. After playing with some online calculators (and stepping back and looking at the big picture) I realize 9:1 is is probably a bad idea once I figure in 6-7psi of boost. I think that puts the effective compression ratio close to 12:1 if I remember correctly. With .030 off the head and the felpro head gasket I believe he'll be around 8.25:1 (I have to check after it's apart) assuming my numbers are even close. This will be the safe bet for the supercharger I guess. Sorry, it's been a learning curve for me. I have not messed with this stuff in 20 years or so and certainly not on this engine.
I really appreciate the input. Another thing I was worried about it gapping the rings. At such a low boost, can we gap the rings to factory specs (maybe just on the higher side of the range) My concern is if he changes his mind about supercharging it half way through the build. This project has been a love/hate type of thing with him, LOL
Jerry

 

[Charrlie_S]

Measure everything as you're taking it apart. Then you will know what to machine, and how much. Don't guess, measure.

 

[Jerry Miller]

Measure everything as you're taking it apart. Then you will know what to machine, and how much. Don't guess, measure.

Agreed. I'm not planning to guess. Just trying to determine what my end numbers should be and develop a plan to get there. As the father I'm expected to have all the answers (and I don't always!) so I'm trying to get ahead of the curve on this as I can.

 

[Charrlie_S]

As the father I'm expected to have all the answers (and I don't always!) .

Boy, that's a novelty. Most youngsters, today, think they have all the answers, and we don't know anything.

 

[Jerry Miller]

Boy, that's a novelty. Most youngsters, today, think they have all the answers, and we don't know anything.

LOL, I have both issues. He's got all the answers until he doesn't and then I damn well better have one for him! LOL! All jokes aside, he's a good kid and very talented with welding and some other things. If he sees this post, I'm sure I'll get yelled at! LOL

 

[TT5.9mag]

Yes. I know we went about things backwards. Originally he was just going to have a normally aspirated engine. When he got the truck, it was low on compression in one cylinder and none in another. We popped the head off and found some bad valves. Cylinder walls looked decent. His budget was much lower at the time (and we had body work and a lot of other stuff on the truck going on) So we gambled and just redid the head. He had no intention of forced induction at the time so we figured let's shave the head a bit. I'm glad he didn't do the full .090 that he was originally planning. Anyway, once the truck was back together it became clear that the bottom end, indeed needed attention. After playing with some online calculators (and stepping back and looking at the big picture) I realize 9:1 is is probably a bad idea once I figure in 6-7psi of boost. I think that puts the effective compression ratio close to 12:1 if I remember correctly. With .030 off the head and the felpro head gasket I believe he'll be around 8.25:1 (I have to check after it's apart) assuming my numbers are even close. This will be the safe bet for the supercharger I guess. Sorry, it's been a learning curve for me. I have not messed with this stuff in 20 years or so and certainly not on this engine.
I really appreciate the input. Another thing I was worried about it gapping the rings. At such a low boost, can we gap the rings to factory specs (maybe just on the higher side of the range) My concern is if he changes his mind about supercharging it half way through the build. This project has been a love/hate type of thing with him, LOL
Jerry

9:1 on 6-8psi can be just fine on 91 octane. You will have to be diligent on tuning it, and very careful with timing. Starting out conservative with timing and rich on the afr, and work up to the perfect tune up. I currently have two engines running, both turbocharged, my daily driver is dead nuts on 9:1 comp and 9 psi and the engine in my boat is 9.2:1 and 11 psi. Both run on junk 91 octane California gas and make big power. I don’t know your tuning abilities but if your at all concerned about understanding how to manipulate timing around peak torque, and after that, or finite carburetor tuning for wot, then I would be a little more conservative with compression ratio.