Guest kc6wfs Posted August 7, 2001 Share Posted August 7, 2001 Well I'm biting the bullet and ordering the Hot Cam from Sallee Chevrolet. Tom over there says there will be enough piston/valve clearance, a good thing. All i have to do is replace the cam,springs,rockers. old ones are 1.5 new are 1.6 ... Question. The motor is 9.4:1 compression. How much will I have to shave off the heads to get 10:1 ?????? Specs on the cam are Dur@Lash Point I:279 E:287 Dur@.050 I:218 E:230 Lift w/1.6 rockers I:.525 E:.525 The heads I have are the 64CC Vortec heads. Running a thiner headgasket is out of the question. I was told not to on cast heads. Tom at Sallee says it will take it from 250hp to 385hp at the flywheel. Sure seems like a big bump just from a cam. Does that sound right??? Thanks.. Dave Quote Link to comment Share on other sites More sharing options...
Guest Night_rider_383 Posted August 7, 2001 Share Posted August 7, 2001 Bud, To me that just seems alittle much form 250 to 385hp out of a cam swap, 1.6 ratio roller rockers at best will give 25 hp. So with that as the baseline that would mean the camshaft will give you 110 hp. I just can't see that much power out of that cam. I would look into the thiner gaskests too. I dont what year engine you got or some of the specs on it but if its like the say mid 70's engine or atleast the same deck hight i cant see why the thiner head gaskets would give you probs. Stock or rebuilt if the block aint been decked then your pistons will be .020-.035'' down in the bore and with .525'' lift cam i cant see where in valve to piston probs will be with a gasket .010'' or so thiner than stock. Quote Link to comment Share on other sites More sharing options...
Ray Posted August 7, 2001 Share Posted August 7, 2001 I know 100 hp from a cam swap sounds like alot but look at the specs for the cam on the 250hp motor. they have a lift like 398 and a short duration... It was designed to work in trucks and heavy vehicles.. I had one in my one ton they fall flat on their face at about 4500 rpm.. and go into valve float soon after.. with a Hot cam kit you can rev the motor to almost 6k. This makes the motor perform like it should.... Good luck great choice.. WARNING you have to lower the valve guides on the vortec heads to run this cam....the max cam a stock vortec head will take is .475 with out the retainer hitting he guide. There is a tool sold by powerhouse that will shorten the guide and enlarge the spring pearch all at once.. if you are using the LT4 springs that come with the Hot Cam kit you will need to cut them down... BTW Scrogin and Dicky had the GM version of the performer RPM available as a take off for 120$. They do alot of custom crate motors and have alot of new parts that were pulled off to install aftermarket stuff....you just have to call and ask... Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 7, 2001 Share Posted August 7, 2001 I've seen Ross C say that the Hot cam is nice but not the best way to go. Ross? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 8, 2001 Share Posted August 8, 2001 I thought the ZZ3 was more like 330 hp or so not 250? My motor was listed at 250 hp and its just a jive universal 350. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 8, 2001 Share Posted August 8, 2001 The ZZ3 has been gone for nearly 10 years. The new ZZ4 is 355 horse and they also have the ZZ430, 430hp but it is twice as expensive as the 355. They also have a motor they call the fast burn 385. As far as power gain, it just depends. If you move the torque band up enough, you could conceivably get 100hp with a decent perfroming set of heads, heads and suitable intake. With a 250hp motor with stock manifolds, intake and exhaust, it wouldn't happen. But if you already have higher flowing intake and headers and your restriction is in the valvetrain, it could. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted August 8, 2001 Share Posted August 8, 2001 Dave, your valves with stock keepers won't clear that lift AFAIK (quite certain!). ZZ4 cam/motor at 355hp can hit 400+ flywheel hp&tq with 1.6 rockers with vortec or 90's Lt1 heads/v. common Impala mod if they've bumped all else to support it (ie. fuel/exhaust/intake etc). The ZZ4 has the old-tech/lazy L98 heads which are it's main inhibitor/that's why the ZZ4 cam is so staggered at .509/.521 or similar... to make up for the lazy L98 exhaust ports. bump to 1.6's on intake and use 1.5's or 1.52's on exhaust and it's almost a dual pattern cam which is fine IF you have great heads like vortecs or Lt1's etc which flow to match that new 'profile'. Dave's stock vortec cam is v. mild and a great setup to make the power it does/100+hp from a sub .400 lift cam to a .520+ lift cam is easily done assuming all else supports it (your heads are great/just make sure you have the valve lift/spring bind issues clear). Generally Sallee is v. good at technical info. PS I'd be leary of bumping compression on your iron-headed vortec too high Dave. 9.4:1 on iron is pretty good.....ZZ4 likes that and I saw the dyno from an impala with both corrected at 400+flywheel. HOT cam has a nice attitude if you like that aspect Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 8, 2001 Share Posted August 8, 2001 I think you mean the fast burn heads as the reverse cooled LT1 heads won't work on a ZZ crate motor. I agree that the money is better spent on different heads rather than the cam swap. AFR. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted August 8, 2001 Share Posted August 8, 2001 quote: Originally posted by Mike C: I agree that the money is better spent on different heads rather than the cam swap. AFR. Dave's motor is a 2000 model Vortec so his heads are fine, just needs room for the lift, Ray's got the ticket above/offset keepers can gain you room as well (I think that info I sent you a while back Dave detailed that). I agree on most older OEM heads that new heads are a great spot for an upgrade. Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted August 8, 2001 Share Posted August 8, 2001 Hi Ross and all, Yes it is a newer 2000 model Vortec. It's a plain jane truck motor i'm finding out. But there is the cam that is holding it way back. The lower end is used in the ZZ# motors and it is a 4 bolt main block. A good thing. The Vortec heads a great heads. I agree with you Ross on not shaving the heads, they are the weak link I guess. As far as the keepers new ones come with the kit that Tom will make up for me. He says I'll not need to remove the heads. P.S. Ross, I just sent out your MO for the brackets. Thanks. Dave Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted August 9, 2001 Share Posted August 9, 2001 Dave, that explains why your motor seemed like such a stump puller! LOL. Sounds good buddy, going to pull on the dyno again after the cam swap etc? later bud- Evan Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted August 9, 2001 Share Posted August 9, 2001 Hi Evan, Ya.. Will do the dyno again!!! It will be several weeks though. Dave Quote Link to comment Share on other sites More sharing options...
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