Anyone have any knowledge of someone doing this to a crate ZZ502??
Would love to know the results, as I question how
well the stock heads flow.
Thanks In Advance

I have Procharged several small blocks and a couple of big blocks, but never a crate engine. What compression are they rated at? I'm positive that even the stock heads can make a lot of power with the blower.

What are your power goals?

Jody

Would like to see at least a 200-250hp increase if possible, just to justifie the cost of the charger. Stock compression is advertised at
9.6 to 1. Stock heads (edelbrock with larger intake valves) flow 299-210 cfm @ .600 with the
stock cam at about 224-234 on a 110 lsa.
Thanks
Hossman

I'm going to venture that a 200-250 hp gain should not be a problem.

The ZZ502 has all the stuff that's good to have for a blower; all the rotating assembly and pistons are forged. The 9.6:1 compression, while high for a roots blower is actually good for a centrifugal application. Aluminum heads are a plus as they will help supress detonation.

However, I would suggest changing the cam. A swap to something with a wider lobe center would do some good, building more boost earlier. I'm not saying the stock cam wouldn't work, but with a purpose-grind blower cam you'll make more power and the boost will "come in" earlier in the RPM range which is always a plus.

Are you thinking of going blow-thru carb or EFI? I was running my combo as blow-thru, and with the exception of it being on the rich side constantly it worked great. Very smooth and excellent driveability. While I was happy with it I am converting to EFI to eek out a bit more gas mileage, run cleaner & leaner at cruise, and also for the on-the-fly correction that a wideband system can do.

Troy

I agree with Troy, that won't be very tough to achieve. If you're going to do a blow through carb call Scott at SD Concept Engineering (401) 732-4047. He did one for me as well as Troys and they worked very well. The carb is a critical part to get the driveability good. He also is a ProCharger dealer and has very good pricing. He will also spec out a cam for you if you like. The cam change is a very good idea by the way.

Jody

I spoke with Scott last week and he basically advise me that with the current heads I have, I would be lucky to make 600hp with any unit. He suggested the Canfield 310's.

I am sure Scott knows what he is talking about, but I am having a hard time accepting this engine
cannot make 700hp with the blower, hence my reason for wanting to check around to see if it had been done before and the results.

With a cam and minor port work, I know of a few people making 475-490 rwhp which I would think would equal about 600+ at the crank in NA form.

Guess I just have blower fever??
Hossman

Well, for the first time in my life I'll disagree with Scott. No way that would only make 600 HP no matter the blower. No way. I can't believe he said that. I'm guessing there has to be a misunderstanding here somewhere.

Jody

Originally posted by camcojb:
Well, for the first time in my life I'll disagree with Scott. No way that would only make 600 HP no matter the blower. No way. I can't believe he said that. I'm guessing there has to be a misunderstanding here somewhere.

Jody I'm also for the first time in my life going to disagree with Scott. The man has NEVER sent me down a wrong path and has always been a wealth of knowledge, but either he's started smoking crack lately and it's gone to his head (hehe) or there was some misunderstanding during your phone call. There is no way you'll be limited to 600hp with a Procharger on a ZZ502 unless you swap the Procharger for one of those $59.99 "electric superchargers" off ebay.

I'd call him back and talk to him again. And if he still insists, ask him why, and then post his reasons here!

Troy

I know of one in a 87 Monte Carlo SS, I will look around to see if I can find some stats. It is Kevin Low over on the Monte Carlo SS.com site.

Okay, just spoke with Scott. Problem with that engine is in the heads. First off, I've seen many guys chassis dyno those crate motors and show 360 rwhp or so and wondered why if it makes 500 HP at the crank do they make only 360 at the rear wheels. Apparently they do NOT make anywhere near 500 HP. The exhaust port on those Edelbrock designed heads only flows 188 cfm! At least as he's tested them there on his bench. I believe Edelbrock claims just over 200 cfm at .650 lift. Those numbers aren't even good for a small block really, but severely limit a 502 cid engine. You need a monster cam and tight lobe centers to make any power at all. He has done a few and if you do a full port on the heads and get them in the 335 intake/ 260 exhaust area they start to be decent and you could make your 700 hp goal. He doesn't think minor porting will do it, they need a lot of work. He can get them there, but doesn't feel it's worth the effort and money as something like a Canfield will still blow it away.

So I have to agree with Scott on this one. He's done a couple in the past with blowers and all his customers have been very unhappy. The torque will come up but the HP will peak very early and will be low. If you want to make an honest 700 HP you will need to swap heads. They're actually not a real bad head on a smaller 396 engine, but are bad on a 502.

Jody

I am thinking "Scott" was having a bad day when I called.

His first comment was something like the manufactures make all the bucks, but the guys
that make it work, don't make enough.

Been there myself.

He did say if I did put a charger on the stock
502, it would build great torque up to about
3500-4000 and then fall on it's face due to lack
of head flow. Hopefully the blower cam will help
that situation to some extent.
Hossman

In case you were typing the same time as I was, read my post just above your last post.

Jody

I need to order a blower this week for a 496.
What`s the best blow-thru set up? What brand?

Call Dan at Procharger, they've done a 454 and 502 crate engines for a Nova they race. These were written up in Super Chevy. Each in the 1200 HP range is I remember correctly.

Gary

Originally posted by Gary at GMPP:
Call Dan at Procharger, they've done a 454 and 502 crate engines for a Nova they race. These were written up in Super Chevy. Each in the 1200 HP range is I remember correctly.

Gary Gary, what kind of power do those ZZ502's really make? I've been told they're actually closer to 430/440 HP on an engine dyno. You can make a ton of power with a Procharged 454/502 but the problem here seems to be in the heads that come on that particular crate engine. Those 1200 HP examples would not be using those heads, and are purpose built race engines.

Jody

188 cfm on the exhaust?!?!? No wonder Scott said 600hp would be tough. I guess I was wrong to doubt him. Heck, my Dart Pro-1's flow that much on the exhaust side and I haven't done much more than lightly touch them up! That number is truely terrible for a BB head and given the cubic inches exhaling, 188 cfm is a SEVERE limitation.

If that exhaust flow number is correct (and I have nothing but faith in Scott) then I'm going to have to agree with him. The heads have to go if you expect to make decent power.

Troy

The 4545 used GM rectangular port heads and the 502 used 502 heads. The 502's make about 500 on a dyno. The key to 1200+ HP on these engines is really in the intercooler. The Procharger Nova uses an ice water to air unit the size of a big beer cooler mounted in the trunk. They blew through two 4bbl carbs on a low rise dual quad intake. The engines were suprisingly stock, although they did de-stroke the 454HO engine to 427, not sure what they hoped to gain in doing so.
We have built 8-71 blown 502's that make 750 HP on pump gas at 6-7 pounds of boost, with no cooler.Even built one at 620 hp at 3-4 lbs. that ran on 89 octane.

Gary's right...the factory aluminum GM (ie Edelbrock made) ZZ502 heads will support alot ponies under forced induction. The only head work I had done was to have the intake runners port matched to the blowers' intake. With a roots style 8-71, it made 791hp on pump gas with 6.5lbs of boost. The cam I use is a bit bigger grind than the stock ZZ502 profile.

That's good news, but if Scott is correct on his flow numbers I don't see how you're doing it. Have the heads used on these engines changed? The flow numbers he's seen for these heads on the exhaust side are pitiful and would be a huge bottleneck.

Jody

Just a guess, but maybe he's thinking of the "tow" version of the 502 crate motor? Not even sure if they still make that one, but remember it was low on hp (like 340), but made up in lowend torque...

I was under the impression that the ZZ-502 was a cam change away from 600 h.p. :(

I was hoping a procharger, would produce silly horsepower, you know the kind you can't really use, but makes you laugh and giggle like a 6 year old hopped up on pixie stix, and a Sponge Bob marathon.

I think Scott is confused, In Chevy Hi performance, NOvember 2001, they tore down and rebuilt a crate 502 and kept it all stock except for a few things(listed here), they did a flow comparsion between the heads stock,and a port job stock was
lift int exh
200 146 129
300 210 159
400 258 187
500 293 213
600 317 236
after only a simple bowl job they increase CFM with a max of 18 CFM on intakes and the same with the exhaust at different lifts. They picked up a lot of CFM on the exhaust from 300 lift all the way up to 600, the intake picked up the most lift from 250-400 lift.
HEads seem decent to me, I bought a set, but then sent them back and went with the AFR's. These numbers were from a superflow600
everything else was stock except for an 830CFM HP holley carb, and an HEI dist. 1 3/4 headers and a full exhaust;
607 torque@ 3600rpm
527horse@ 5400 rpm
they tried open exhaust with 2 1/8 headers and gained 26 horse and torque stayed the same.

Just would like to thank everyone for the input, as it was very helpful in my decision.

I will throw the Procharger on this winter with the stock heads, and if I don't make 750-800hp,
I will buy the Canfields.
Thanks
Hossman

There you go, problem solved! I made 800+ rwhp with both a 468 and a 540 with ported Canfields; the heads flat-out work!

Jody