AlwaysCode390

I wrote down the numbers that were on my block/crank when I was in the engine a few years back. Well I want to add a 142 weiand blower and was wondering if the heads/crank I have are good enough .... or if I should upgrade (its all stock, but GOOD stock parts). How do I find my compression ratio....the pistons have been in there for 20 years, lol ( they have 4 divots on the top ).

*** #4577 (front ) and CMT (rear ) of crank = Forged Steel, SMALL journal, 3.25" stroke (arent the SMALL journals the best, and forged is great too?)

*** #3884520 , # gm26, #H1 6, # gm32, # G286 = 60cc chamber, 1.72" intake and 1.5" exhaust ( all the info I could find ).

Thanks , if I should upgrade, please offer advice ---

AlwaysCode390

The guys on Camaros.net are recommending I get a new crank, cam, and heads.....time for a rebuild!!! ---

ps, any suggestions on good heads? ---

confused327

those heads are awful. just about anything is better.

if your going to abuse this motor, i would put forged pistons in it and have the machine shop check out the rest of the rotating assembly

cplthomas

What are you using this motor for? The block is either a 283 or a 327. You will have poor low rpm torque but the 327 can rev and will scream torque at higher rpm's. I would go with some 'double hump' hi-po heads (gm). Get forged everything, like confused said and a new upper end (cam, lifters etc...) Go here for calculating the compresion ratio http://www.hotroddersauctions.com/Dy...Calculator.php Have fun.

AlwaysCode390

I guess I will go ported aluminum heads with large valves (suggestions?), a new cam ( right now I have the "l79" cam 222 222 .447 .447 @ 114 ... suggestions? ) , and a large journal stroker crank ( does it require block work to change from a small to a large journal crank? ), then go roller cam (with block work) and 4 bolt mains ( with block work) .

THANKS ---

ps. It will be a weekend cruiser/track runner ( I want 500hp out of it ) ---

MachinistOne

Sell the small journal block to someone who wants it for restoration work and start with a standard 350 block.

What I did for my street cruiser motor(10 years ago), is found a late model 4 bolt main block out of a 90's TBI truck - these are already set up for hydraulic roller cams and will be cheaper in the long run if you can find one. I used a Scat forged 3.750 crank, Scat h-beams, and some Wiseco pistons. The cam was a mild Isky hydraulic roller and the heads are AFR 195cc with an RPM air-gap manifold. Compression was pump gas friendly at 9.6....you can easily reach 500 with a bigger cam than I used and bump the compression to 10:1.

Don't use an Isky cam for hydraulic roller apps, the comp grinds are much better than they were 10 years ago and will make more power than the old design Isky's.

These questions will help:

How much can you spend?

500 RWHP or 500 Flywheel?

Do you really want to use that little blower?

Can you afford to upgrade drivetrain components to support the HP?

If you are only shooting for 500hp ditch the blower, because you will put the same amount of money into both motors - if you want to use the blower you might as well shoot for 600+

cplthomas

[QUOTE=MachinistOne;4454001]Sell the small journal block to someone who wants it for restoration work and start with a standard 350 block.

What I did for my street cruiser motor(10 years ago), is found a late model 4 bolt main block out of a 90's TBI truck - these are already set up for hydraulic roller cams and will be cheaper in the long run if you can find one. I used a Scat forged 3.750 crank, Scat h-beams, and some Wiseco pistons. The cam was a mild Isky hydraulic roller and the heads are AFR 195cc with an RPM air-gap manifold. Compression was pump gas friendly at 9.6....you can easily reach 500 with a bigger cam than I used and bump the compression to 10:1.

Don't use an Isky cam for hydraulic roller apps, the comp grinds are much better than they were 10 years ago and will make more power than the old design Isky's.

These questions will help:

How much can you spend?

500 RWHP or 500 Flywheel?

Do you really want to use that little blower?

Can you afford to upgrade drivetrain components to support the HP?

If you are only shooting for 500hp ditch the blower, because you will put the same amount of money into both motors - if you want to use the blower you might as well shoot for 600+[/QUOTE]


I agree, a blown 327 is kind of like kissing your sister.

AlwaysCode390

HAHA you guys are funny. I wanted to keep with the 327 because I already have a 600hp lt1 (350) and was looking for something a lil' different....plus it IS a 327 and the matching block for my car, so thats different AND cool if you ask me

I was using nitrous on the lt1, turbo on the Sy, and thought a nice small blower under the hood on my 67 would add to the distinction. Now you guys are making me want to put the lt1 into my 67, buy a cheap used lt1 for my 96z ... sell my 96 z and call it a day!!!

Seriously money is not a problem ( I dont have much, but make decent), I put about $10gs into my lt1, and about to do the same to the Syclone. I am definately looking for QUALITY.

1. $10g's or less
2. 500 rear would make me happy, but more wouldnt hurt
3. I wanted a blower I could tuck under my l-88 cowl, but lately was pushing around using a pro blower (the turbo looking ones...forgot the name ), and this has the B&M superjection fuel injection blower setup that has been modded for 500hp (fuel rails, injectors, ect)
4. Yes, right now I have 4.10's, a custom length aluminum driveshaft, and a worked turbo 400....dreading a 12 bolt swap because thats a ton of cash on one peice....but if the 10 bolt wont work whats the other option, lol ( I have a ta rear peice with the main bolt supports ).

MachinistOne

Set of good heads and a blower cam will get you the number your after.

AlwaysCode390

Thanks for your time....I will search into the AFR 195cc heads since that was your recommendation

What is involved with changing my 67 block to a large journal crank, and a roller cam? $$$ and work wise.....Thanks ---

AlwaysCode390

I think I decided I will leave the crank since its forged, go .030 overbore w/ 4 bolt splayed main caps, go to a roller cam custom made for the smaller blower, 5.7 eagle h-beams, ported afr or dart heads (opinions?), 1.6 comp magnum rockers, the weiand 142 and that b&m superjection fuel injection setup I have for the blower with modified fuel rails and injectors. Finish it off with true duals and longtubes, beef up the th400 and get a stall....and replace the 10 bolt with a 12 bolt when it finally snaps. Sound good? Cost effective doesnt really matter. I just dont want another stroked 350 like my lt1....sorta going for something "different". That stock crank should be stong enough right....or should I get it nitrided too? Thanks---

Are there guys running meth injection setups on blowers like this or is it not worth the trouble? I plan on running a wideband for a decent idea on my tune too ---
__________________

confused327

i think the first gens have the 8.5" 10 bolt, they are much better than the 3rd and 4th gen 7.5" rears. a 12 bolt is 8.875.

everything sounds good, but a 177 would be more fun. meth/alky wouldn't be a bad idea with the heat roots blowers make

AlwaysCode390

Thank you very much. I think I have my setup figured out ---

Damon

I've got some experience with the "little" blowers. Enough that I'm on the 4th itteration of my engine with one, and I figured out how to make it belt out some power without grenading. Mine's on a 383 but there's no reason this wouldn't mostly translate over to a 327.

Crank.... stock forged is plenty good. I have a $199 Summit cheapie cast crank in my 383 and it's survived all 4 itterations of my combo without ANY problems.

Pistons.... choose something that will get you down under 8.5:1 (and I recommend forged slugs with the top ring gaps opened up about .004"). Preferrably 8:1 compression. I've learned from painful experience that dancing on the edge with compression is NOT what you want to do. Took forever to pound it through my head that 8:1 IS HIGH CMPRESSION with a roots blower on pump gas. This ain't anything like a centrifugal or nitrous- totally different animal. And no, you won't lose even a smidge of bottom end torque with the lower compression (becuase you'll be able to use the right amount of spark advance for optimum power).

Good heads pay dividends on a roots motor just like they do a N/A one. You want good exhaust ports, though. Now you won't make much more power DIRECTLY becuase of the better heads but you WILL do it with less boost showing in the intake (assuming same blower pulley ratio in both cases). Again with the detonation issue- more intake boost equals more heat and that means less power and greater chances of detonation. And believe me, detonation is always just around the corner with these little blowers. If you can make the same power showing 1-2 PSI less boost on the gague, believe me, that's the way you want to do it! Good heads will do that for you.

Cam- SMALL. You don't need a lot of duration. The blower is all done around 5500-6000 RPMs. No point in camming it to go any higher. Bigger cams DO NOT HELP! The blower is so small you need to use what little it can deliver EFFICIENTLY. You don't want to be blowing precious boost right out the exhaust. 210-220* on the intake is PLENTY. About 10* more on the exhaust. And a wide LSA- 112* minimum, 114* preferred. My cam is a flat tappet hydraulic with 214/224* on a 112* LSA and I am finally satisfied with my choice (having tried larger cams with mediocre results). Never ran a roller but I would think you could go even smaller than I did but get the same amount of air through the motor.

There's a million little tips and tricks I could probably give you on the combo, but that covers the basics on the hard engine components. Feel free to email me if you like.

My combo:

383, cast drank, stock 5.7 rods with upgraded rod bolts
-28cc d-dished pistons for true compression right at 8:1 with the rest of the bombo, below
74cc AFR 190 heads
GMPP .028" thick composite head gaskets (cheap and effective at $35 a set)
Weiand 142 blower
larger 7" bottom pulley, stock 3.07" top pulley (one pulley change from fully maxed out)
Hydraulic flat tappet cam with 214/224* on 112* LSA with cheap stamped 1.6 rockers
Home-tweaked QJet carb. Yes, a QJet. But you're going FI, so who's really the crazyest here?
Home tweaked HEI distributor. Recurved by yours truly to work with the blower and fortified with vitamin MSD (module and coil combo only- NO BOX!)
28* total timing, all in by 2800. Yes, I run vacuum advance but that's a whole other subject
Cheap longtube headers and dual exhaust. And I do mean cheap.

As such, it was showing 5 PSI of boost and belted out 390HP to the rear wheels at only 5500 with a torque curve that looks like no N/A small block ever built (more torque the lower you go, to the point of rediculousness). And all the boost is there RIGH NOW- as low as you care to stab it it goes instantly to 4.5-5 PSI and stays there up through the entire gear. Stock 450HP Vipers were laying the same number down on the same dyno the same day I was there. So I figure a LEGIT 450+ HP and more torque than I could ever use coming out of the hole. Driving it on street tires, even with my old TH-350 trans and 2.73 rear gears is absolutely stupid. First gear is useless. I can punch it at 35 MPH and spin it off into the ditch if I stay in it too long. On street tires, just like I drive it on the street, a high 12 at 113-114 is no problem, if I can launch good and not spin through 1st. I've done better with it (12.69), but it's tough to reliably lay down a mind-blowing ET number on street tires.

It won't drive anything like a 600HP N/A LT-1 spinning out to probably 7000 or more. It just don't work like that with these little blowers. But it's very entertaining to drive. And you don't need anything exotic to make it work- it's totally drivable and docile like a stock motor. I dare say you could even get good mileage with it if you set it up right and tune it sharp. It just makes a ton more torque than a stock motor. Like having a mild big block instead of a small block under the hood.

AlwaysCode390

Wow Damon BEST POST EVER..... you seriously just taught me SO much.

I wish I knew what pistons I had in my car , because then I would just skip the rebuild and bore....throw on some AFR Eliminator heads with 195 runners, 74cc chambers and big valves .... port the blower's manifold to the heads; install the FI and start tuning!!! Right now I have the l79 cam which is .447/.447 222/222 @ 114 so it wouldnt be worth swapping it out (very close to your cam and it only has 3k miles on it). I have forged stock rods.....and it would be nice to go h-beams but if the crank is strong enough I am sure the rods will be fine. The engine has 84,000 miles on it and has been rebuilt once already.

What lift are you running and what size stall do you recommend for my th400 and 4.10 gears?

Once again thanks SO much ---