"Lil Alky", the epic build thread

[alkygto]

They've had drilled blower rotors for a while. Unless your full out racing, it's not recommended as the rotors will warp and have to be replaced often.

Yeah, they have had drilled rotors for a while, my 6-71 has them, as do all 71 series GMC blowers for the past 60+ years. Where do you get your information on "warped" rotors? If the rotors "warp" they'd lock up in the case, I have'nt seen that and I've seen quite a few of these with over 100,000 miles on them.

[matt5112]

what sort of blower speeds though?

6-71's are hardly spinning on a small block IIRC.

[alkygto]

True, mine's 12% overdriven on a BIG block so thats roughly half the speed some eatons spin but with much more mass. I'd still like to see a case of bored rotors warping. I think it would also depend on the amount of material removed and even the method of boring/drilling.

Regardless, I'll be going this route and I can't wait to hear it scream it's ass off. Should rev pretty quick if I'm spinning half the mass in the eaton.

[matt5112]

3.4 pulley results in a 2.1 drive ratio. 12 000+ rpm. still quiet imo.

looking forward to results.

[alkygto]

The Cobra guys are spinning theirs to 18,000 + and they use the same bearings and thier rotors being longer have more mass. By that time though they are on the downside of adiabatic efficiancy and the heat is the killer, reducing bearing clearances and thinning the viscocity of the oil and grease. Bob's Venom Cooler is reportedly reducing case temps by 100 deg.

[matt5112]

I'm sure efficiency was going down after 10-13 K

Edit:

Looking at my temp log from july, it seems there was about a 10* difference between the snout and the case.

Note this was with a 3.4 pulley and an intercooler.

For most I'd suggest looking into the current temps before investing in something like this.

[alkygto]

Well..... not according to the blower dyno I built. It actually started a huge upswing around 12K on it's way to flowing way over 1000 cfm. 825 cfm at 14K.

[matt5112]

volumetric increases yes, but not adiabatic

[alkygto]

It's not linear.

Heat soak is the main issue. Controlling charge air temps is critical of course. What temps were you recording? I've never checked mine but I know the Cobras are seeing 200+ deg on the supercharger case. The Venom cooler was reducing that by 100 deg. Now sure, the intercooler is cooling the air charge but that air has to pass through the hot supercharger case and is not only being heated by compression but by convection from the case. Now you have cooler air before it hits the intercooler improving it's efficiancy. The VC would be great for you because you just plumb it into your existing intercooler.

Bob's not touting it's power improving merits, he's only saying that it improves the longevity of bearings and seals for guys that are really spinning the **** out of these Eatons. But I know he's seen better #'s with it than without.

Edit:

KB has started liquid cooling their superchargers and Eaton has applied for patents on it's own system for the OEM's, this I know for sure.

[matt5112]

How would that improve the efficiency of the intercooler?

If anything it'd reduce the overall efficiency by resulting in an overall higher intercooler fluid temp.

I measured the surface temperatures of the snout, case among other things.

I have no dispute with the claims of longevity. Until I see a larger delta between the case and the snout I'll focus my efforts elsewhere.

Good to know this is an option though.

Also very interested in the drilled rotors.

[alkygto]

How would that improve the efficiency of the intercooler?

If anything it'd reduce the overall efficiency by resulting in an overall higher intercooler fluid temp.

I measured the surface temperatures of the snout, case among other things.

I have no dispute with the claims of longevity. Until I see a larger delta between the case and the snout I'll focus my efforts elsewhere.

Good to know this is an option though.

Also very interested in the drilled rotors.

The air charge is'nt as hot when it gets to the intercooler because it has'nt been subjected to latent heat in the supercharger. We're not seeing higher intercooler fluid temps, they're basically the same. Case and snout temps are eaqually reduced, same phenomena you are seeing, about 5-10 deg difference between the two, only 100 deg less than without the VC.

Did'nt go by Stiege's today, spent the day organizing my junk to go to the machine shop Monday and on porting my heads. I'm about done and I'll save the rest for tomarrow.

It's Miller time. Well, maybe Jose' Quervo Black and Dos XX's time..........

[matt5112]

The air charge is'nt as hot when it gets to the intercooler because it has'nt been subjected to latent heat in the supercharger. We're not seeing higher intercooler fluid temps, they're basically the same. Case and snout temps are eaqually reduced, same phenomena you are seeing, about 5-10 deg difference between the two, only 100 deg less than without the VC.

Looks like this might be more efficient than it initially appeared.

Will need to solve the stock head/valvetrain issue first of course.

[alkygto]

Well.........my frustrations have already started. Yesterday I "organized" all my shiz and today when I'm loading up to go to the machine shop I get a hair and open up the box of ARP mainstuds. Eight mainstuds and hardware. No side bolts?!?!?!? ? Well, then I start looking for the six side bolts and I can't find the old ones. Main bolts are in the block. Are'nt the original sidebolts TTY? I could steal the ones out of my spair motor but if they are TTY then I can't use em anywho. Dealer item? ZZP? Other source? I'm assuming I'll need these when they hone the mains so I'll need em quick! Help me out peoples!


Guess I should'nt have hit the Jose' last night.

[alkygto]

Okay, liberated the needed bolts from my parts motor to get to the machine shop. Ordered all new standard bearings and rings from ZZ perf as well as some gaskets and other ancillary items.

Finished up porting the heads and took them by Stiegemeiers for a valve job and seals. Guides were in excellent shape so I'll save a few bucks there. He's also gonna set me up with some LS valve springs and look at valve options.

Talked to him about the Venom Cooler and some lightwieght rotors. I'm on the list but we'll have to see how time goes. I might put it together with the Snake Bite (starting with a stock size or 3.6 Billetflow pulley) and he's gonna prototype the Venom Cooler for GTP M90's on my car. He's working on a separate heat exhanger and pump setup to work without an intercooler just to see what it does.

Liquid cooled supercharger. Mmmmmmmm. Sounds sexy. Later on, when I step up to an intercooler I'll be ready.

[matt5112]

smaller valves might be more ideal here.

[blueguy]

The main's side bolts aren't TTY...

Just for future reference...

[alkygto]

smaller valves might be more ideal here.

Huh?

[alkygto]

The main's side bolts aren't TTY...

Just for future reference...

Good to know sir, thank you. I'll have a lil more peace of mind.

[Bio248]

pictures of the heads after you ported them?

[matt5112]

larger that stock, but not as large as say IS3 heads.