Does anyone have the lift info for the GM "hot cam" :cool: that one can purchase for the zz4 motor. I'm looking to improve the performance of my zz4. The cam in it has .475/.525 lift. Anyone have suggustions? smile.gif

http://www.sdpc2000.com/catalog/540/products/1087/LT4-HOT-Cam-218-228-Duration-0_050-Hydraulic-Roller-Camshaft.htm

Sorry the lift was wrong. .474/.510.

Hot cam is 218/228 with .525 lift on 1.6 rockers. I have a brand new one that I'm not going to use if you're interested. Email me at 81vette4speed@cox.net. HTH

Here are some measured specs. A different cam might measure a bit different, factory tolerances, you know.

Chevy Hot Cam:
Hydraulic Roller
adv--dur________279/287
.050___________119.1/229.3
.100___________187.7/197
.200___________135.8/143.1
LSA___________112

Pat -

What lobe lift did you use as the "advertised" points?

The SDPC site didn't mention that the lift it advertises requires 1.6 rockers. They really should put that on there. That cam was originally released as part of a complete kit, that included a set of 1.6 rockers. With 1.5 rockers, the theoretical valve lift is about .492".

That cam is optimized for FI motors, and specifically for the LT1/LT4 motor. As such, it has several compromises in its design, that are unnecessary if used with a carb. IMO you can do alot better by using a cam that doesn't suffer from that shortcoming.

I have this cam and have used it both with a 670 avenger now I have tune port F1. I haven't had the FI long enough to make a seat of the pant's comparison. I can tell you the cam is pretty mild.
Here are some numbers courtesy of Pat Kelly I had saved on my computer. These represent a 383 with
vortec heads someone had asked about in the past.


DCR1 (http://home.hot.rr.com/importtech/chevelle/383engine/hotcam_dcr.doc)

DCR2 (http://home.hot.rr.com/importtech/chevelle/383engine/hotcam_dcr2.doc)

I don't know what lift was used for adv dur. I didn't measure it. It must be close to what the factory used. Here are some more specs. (http://www.sallee-chevrolet.com/Cam_Specs/GMPP_Small_Block.html)

Maybe this helps.....

http://img.photobucket.com/albums/v61/gort69/hotcamcard.jpg

Well, does anyone want to make a suggustions as to a certain cam or company to replace the original cam in the zz4. I thought the "hot cam" would be a good choice, but this is my first built so I'm still learning.

Originally posted by Aaron:
Well, does anyone want to make a suggustions as to a certain cam or company to replace the original cam in the zz4. I thought the "hot cam" would be a good choice, but this is my first built so I'm still learning. The Hot cam is a great choice. No, it's it's not the biggest, baddest, rumpity rump cam you can find for sure, but with 1.6 rockers it should wake your ZZ4 up to the tune of about 40hp, while retaining about 15" of idle vacuum. Plus, anything with more than the hot cam's .525 lift will require a spring change. As it is, the stock ZZ4 springs are the same as the recommended hot cam springs.

A couple of other nice choices, which don't require the expense of new rockers and allow you to keep your current springs are the Comp xr276hr or the xr282hr. These are considerably more aggressive than the hot cam, and would drop your idle vac a fair amount.

PS The hot cam doesn't "require" 1.6 rockers, but to get the .525 lift that's what you need. .492 lift with 1.5's.

I love it!!

He, He!!

Right around the 268/270/272 advertized degrees intake duration for max. midrange grunt production TOO!!!!

They've just using roller lifters to get the lift up there is all....

That's what you need to do it, imho...

pdq67

Thanks, guys. I probably will go with the "hot cam". I would like to get a great sounding small block as well. Does the "hot cam" has some lope to it. The zz4 is not bad, but everyone likes that sweet sounding small block. MyBoTy I interested and will email you.

Originally posted by Aaron:
Does the "hot cam" has some lope to it. Some, but not a lot! I've heard referred to a "stealth" cam - silent but deadly. Great street cam - makes lots of torque lower in the RPM range. Remember - it's really designed to be used with 1.6 ratio rockers.

The 276hr or 282hr will have a lopier idle for sure, and will make their peak torque higher up.

I built a ZZ4 short block, the complete Hot Cam kit, and Vortec heads for my '80 Camaro.
A very strong street motor! ;)
Slight lope at idle...ran lowest 13s.

I have the kit sitting on my workbench waiting to go into my ZZ4. I found this graph a while back from CHP. It compares the ZZ4 cam to the HOTCAM with 1.6 rockers. A little porting to the ZZ4's L98 heads, an RPM intake and it'll be closer to 420 HP. Not bad for an engine that idles smoothly, has good vacuum, and can be driven every day without a second thought.

http://www.chevelles.com/showroom/ZZ69chevelle/HotcamGraph.jpg

DP

FYI, you can get a hot cam kit which includes cam, rockers, springs, retainers, spring shims and keepers for $500.

Peter

It seems the "hot cam" is a good value for the buck. I have been research this some more and have found this info. What is your opinion of it.

The "stock" zz4 valve spring is weak in the long run since the .525 is the MAX recommend for the spring. Which is what the "Hot Cam" produces.

Comp Cams offers there new "beehive" spring which will fit the stock spring seat and a MAX lift of .625.

If this is the case, would you be better off running the Comp Cams XE276HR-10.

Motor would be running the 1.6 rockers. I figure since I would not have to machine the heads then you might as well run a more aggressive cam. If power is you game. I plan on porting the heads anyway.

I check up at lt1tech.com every now and then and there are people there that don't like the beehive springs much. They just don't seem right to me either.

Peter