Winter Project: I'm currently replacing my Opticrap and since I've got the front of my engine ripped apart I thought I would go with an electric water pump, underdrive pulley, and a new cam. I don't want to have to mess with anything up there again.

What kind of cam would you guys recomend? I really need the midrange power with my 2.59Auto. I was thinking of going with the ZZ-9 from TPIS. I need a cam that will work with my stock Opti since I just bought a new one. I don't think the Lt4 Hotcam makes that requirement, please correct me if I'm wrong.

What else do I have to replace to get the cam to function properly? Rocker arms, springs, anything else?


Thanks guys--MN_Vette
'93 auto Polo Green Vette
The FIRST and ONLY car I've ever owned!

 

Get the hot cam! It'll work with either style opti, you'll just have to tap in the opti drive pin a little bit, the instructions should explain it. With the electric water pump on my car with the hot cam and 1.6 roller rockers I picked up 44 horsepower, completely stock exhaust and heads. Your pulleys should be good for a few more. 50 extra horses is real nice. The hot cam won't give up any low torque but it really comes alive in the upper range and pulls like crazy all the way up to the red line.

The ZZ cam might do the same, but it won't be as cheap as the hot cam.

You can check out all my dyno stuff here and see if it'll help you make your choice. http://24.17.202.123/htmls/dyno_corvette.html

If you do get the hot cam, be sure and add my "Hot Cam" graphic to your sig and join my club ;)

 

go get the hotcam

 

If you're doing the cam, you may want to also replace the lifters, pushrods, and valve springs (adding roller rockers certainly wouldn't hurt either). You can use the original lifters, etc. but you may just want to replace them anyway. For the cam, you may want to contact Chris at http://www.speeddemonmotorsports.com. He's been very helpful with my cam selection and you may find a different cam given the fact that you're running an auto vs. a 6-speed. Hope this helps. :)

 

I just got a copy of Summit Racing Catalog in the mail and in the new products section they show 4 LT1 specific cams from Comp. Cams. I to have always heard that the Hot Cam would loose low end torque and was not recomnended for autos. But looking at Nathens Graphs it sure dosnt look like it did. I wonder if anyone on here has put it in a auto (350 cid) and how it worked? Good luck with your decision.

 

When you say upper range are you refering to 4,000+ rpm's? My biggest problem is when i shift into second and the rpm's drop to 3,000 at ~55mph. It takes a while to get out of that range and I don't see redline again until just over 100mph.

 

It's all really gonna depend on the gear ratios in the tranny. In my case I effectively raised the redline from 5700 to 6300, meaning that when I shift I'm already higher in the revs for the next gear.

Let me give you an example in my case. If I hold out first gear to the top that's something like 52 mph. Then if I put it in second the same 50 mph is right around 4000 rpms. In stock form I could only hold 1st until around 48 mph, that puts me around 3900 when I shift. As you can see it's not too much of a difference. What it sounds like is that your auto has too steep a step between gears, which is understandable considering you have less of them. I'm not sure how much difference it will make, but it certainly won't hurt. The hot cam really pulls hard everywhere, but it pulls harder after you cross the 4000 rpm range. If I'm drifting along in first and slowly push it up to 4000 rpms, 6000 will come up in about half a second if I nail it.

There isn't really a dead zone with this cam, it starts to drop power after around 6300 or so I have been told, but I don't push mine past that anyway, so it's really nice. Every one of my available revs is usuable power, it doesn't peak early and then fall away.

 

With the gear you're running, I would recommend the LPE #74211 cam. The specs are 211/219@.050, .503/.525 w/1.5, 112 lsa. The cam will work well even if you upgrade the gear. This is the cam that LPE uses in it's LT1 motors.

 

Was that the Jan-Feb 2002 catalog your talking about, with the mercury cougar on the cover? If so which page was that on, I looked through it and couldn't find it. Maybe I'm just up too early and can't see strait. Thanks

MN_Vette

 

Yes, it is page 7 bottom right hand corner. Also I just noticed that someone has a ZZ-9 cam for sale in the C-4 used parts for sale.

 

I think with 2:59s the Hot cam will have no bottom end power. A 6-speed is even doggy without the 4:10s.

 

I think you going to want some more gear and a looser converter to use the LT4 hot cam. The cam is pretty big jump in duration for 2.59 gear.