anesthes

I've been doing a lot of reading lately. I have a 400 block on the stand all done up ready to go. Bored .060" over, forged crank, eagle rods, forged reverse dome pistons (-16.2cc), etc. No heads or camshaft yet, no torque converter. In another pile, I have some 1 3/4" long tube headers, a performer 750 carb, a performer intake, accessories, water pump. And on a trailer I have the car, a new TH350. I had been thinking of a few different things. 1) I was thinking of some RHS 72cc heads (9.5:1 comp), a hyd-roller cam (280XFI - 230/236 on 113/109 degrees), and a Weiand 177 blower. However reading documentation on the forum here, and on Weiand's website the 177 can support about 475hp, and is meant more for hot 350 engines. 2) Looked at running the same cam and heads (9.5:1 comp), with a blow-through S-trim blower. (carb). Camquest seems to think the combo will make 510hp, 536 foot lbs. 3) Looked at running some RHS 64cc heads (10.2:1 comp), a hyd-roller cam (XR286HR 230/230 on 110/106 degrees), naturally aspirated. Camquest seems to think the combo will make 500hp, 516 foot lbs. Based on these scenarios, the Weiand is pretty much off the table, and the blow through S-trim seems to not be worth the additional cost over NA. For another scenario, which would cost something between a Naturally aspirated RHS head setup, and a S-trim we can exchange the RHS heads for a pair of AFR 195 eliminators 4) AFR 195cc 'eliminator' 65cc port (10.1:1 comp), a hyd-roller cam (XR282HR 230/236 on 110/106 degrees), naturally aspirated. Camquest seems to think the combo will make 511hp, 513 foot lbs. The XR282HR has faster ramps than the XR286, but a little less lift. Given the choice, I'd probably run the XR282 with 1.6 rockers vs the XR286 with 1.5 rockers. But anyhow. The point here is, I can't seem to find an economical justification of going with a blower on this 412 combo.. I was kind of expecting to see the simulators peg 550+hp out of a S-trim.. I chose an S-trim in these scenarios because of cost. S-trims can be had for $800-1000 used all day. Brackets are easy to fabricate, and carb hats are $100. $1200 or so for a blow through setup, vs $1200 or so for a used weiand supercharger. If we play with a weiand 671 for example, we can make close to 600hp however between the cost ($2500 or so) of a 671 setup, and the fact that it sticks about 11" out of the hood is a turn off. -- Joe

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1979 Z28 "412" - 400 Block, .060 reverse domes, eagle SIR rods, forged crank, XR288HR cam, AFR 195 heads, 10.9:1 compression.

TPl383

hp/tr all beiing close n/a vs an s trim. Id say it comes down to what do you want.
As you said you can make the brackets and stuff. why not spend a little more and go ysi/d1/novi 2000, or something along those lines.

then again a 6or871 always looks bad a$$ sticking out the hood of anything.

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anesthes

Been doing a lot more reading, and blow through carb seems to be a tuning nightmare.

Is there a smaller blower than a 671 (roots) that will make close to 600hp?

Like I said, I was looking at the weiand 177s but it seems they target the 500hp range and I can do that naturally aspirated..

I kind of figured this thread would get a few more hits.


If I was going EFI with the car I'd probably go with a bigger centrifigul blower for sure, but when you consider the cost involved with a full EFI swap on a carbed car (1979) it kind of puts me into the "I cant justify this" category.


-- Joe

TPl383

Ya, Im shocked this gedding get more hits either.

As for blow thru carbed. Never messed with carbed motors So I dono. I know there are people who swear its just as easy to tune a blowthru over on yellowbullet .com

I dono know of anything between a 177 and 671

tequilaboy

Whipple has some blowers capable of big HP. W200R 300-900 HP. W305R 800-1500 HP.

http://www.whipplesuperchargers.com/...sp?ProdID=1229

Here's an interesting article with some details and pricing info:
http://www.chevyhiperformance.com/te...ild/index.html

Confuzed1

I guess that's all I was getting at.

You're saying 400 plus foot pounds of torque at 5500?? That's pretty darn good. Maybe it's because I'm a rookie, but I've never had much success making the kind of "real world" numbers those programs claim "you should" be making.

Personally, I have found that with my 400, I never seem to make the HP I want, but end up making more torque than I ever expect. For instance, with only 5 pounds of boost, I manage 492 ft. pounds of torque at less than 2800 rpm's to the wheels. But my HP was weaker than I had hoped ...376 RWHP which peaked at 5000 RPM's. So.....it's far from optimal, and most likely due to my smallish 650 carb, and I still run a CAT....(I'm working that out lol)

-But even with so little HP, it's a hand full on the street as it is due to the torque!! -That's really the magic of these roots blowers.

And yes, the cam is a retro-roller cut on a small base circle. PM or email me if your really interested.

EDIT: btw, Thnx for the reply on my other post.

flrtin1

Holley has the 250.....it is the old B&M like my 420..... http://www.holley.com/77-250CSBP-1.asp