96vette 110,000 miles thinking about hot cam, rebuild first or install cam with high miles best et 13.17 @ 104mph [mods cold air & prog III]. buying 2800 stall soon trying for 12.80's this year :U

 

110k is nothin, install the cam

 

I would rebuild first....but thats just me. :D

 

A friend and I are putting a Hot Cam in his 94 right now.. he has 117K.

You can still see hone marks on the cylinder walls...

 

I think that it is a lot of work to install a cam.. I would pull the engine and at the very least check all clearances replace what is necessary and then port the heads and install and degree in the cam. You also run the risk of getting foreign material in the engine when pulling it apart in the car. That is just my opinion. Good luck either way.

 

I really wouldn't go with the Hot Cam in the auto. I really love this cam but it just doesn't seem to do nearly as well in an auto.

 

Nathan's right, the hot cam has been known to cause slight loss of low end which effects throttle feel in autos. Take a look at this thread:
http://forums.corvetteforum.com/zerothread?id=485467

particularly the posts by STL94LT1 and LUVMY92. The cam route they took looks best for an auto.


[Modified by Lone Ranger, 8:13 PM 2/9/2003]

 

Is this still true with 3.73 gears?

Bummer to hear this now. I thought I researched the subject fairly well before going with the LT4 Hot Cam, but now I am worried. I'll be adding full length headers as well.

What do you guys think?

 

What do i think? I think you had a lot of cleaning to do after that little joy ride on the beach :p:

Seriously, with 3.73's I would guess you'd be okay since the rpm's climb quicker. I am by know means an expert, and take anything that issues forth from my tongue with a grain of salt :D Nathan and Vader should be able to advise.

 

Actually I did get nailed, but I pled ignorance and the officer was nice enough to let me go with a verbal warning. Being able to drive on the beach was new for me, finding out it counted as a state road with all the same regulations was also new!

 

I have a 96 Auto.. with 3.73 STOCK cam & 1.6 GM Roller Rockers, 2800 Vigilante I ran 12.28 @ 110mph in very good air, normal in July is 12.5 @107mph..

I had run a best of 12.48 & JUST the 1.6 RR gave me .2 tenth improvement.. I never did anything to my computer except reprogram for 160 thermostat & correct for gear change..

 

Dayuuum! :thumbs:

 

John what kind of tires was that run on? Front/Rear.. Also, if you used slicks how many runs have you put on that Dana 36 and what is its condition? I would like to duplicate your success!! :yesnod:

 

Im Front I'm running Weld Pro Star 3.5 x15 in the rear I tun Weld Pro Stars 10"x15" I use 325 /1515BFG tirs// The dana 36 lasted 6 months before I had to switch to a 44.

The car takes the front wheels off the ground, & I 60' in 1.65- 1.70 Thats about it.. Remove the front sway bar (15lb) remove mufflers 35 lb. Pro Star wheels save you 100 lb total.. usa a 160 state, 1.6 RR & you will be deep in the 12s :D

 

I just finished an LT1/LT4 Hotcam conversion. My engine had 105K and I did pull it to re-ring and replace all bearings (as well as waterpump, Opti rebuild, Extreme roller timing set, oil pump, lifters, LT4 injectors etc.). Original wear on the engine was impressively nominal. I almost felt like I was wasting my money replacing the original parts. But since I plan on spinning it to 6200-6300 rpm I thought it would be wise.

I am running 2.59's for the moment and an Edge Racing 9.5" 2800 stall converter. Overall, the combination runs terrific. Right now I've got the tranny shifting at 5850rpm while doing tuning in the lower rpm ranges and the power difference (even with several hundred rpm untapped) is quite noticeable compared to a stock LT1. The 100-140mph pull in 3rd gear (with converter locked) is much stronger. The more generous stall converter matches up well with the cam and minor stabs of the throttle produce a lot of wheelspin (any time you want) in 1st gear. Even with the 2.59's.

Since you have a '96 with an auto this next item is pretty important. The '96's have a crank position sensor required by the OBDII standards. It is supposed to detect misfires (for emission purposes) and is quite sensitive.
So sensitive that even in a stock car, a smaller diameter stall converter or a slightly unbalanced aftermarket pulley can trigger it since the "misfire" is actually a computed angular velocity discrepancy. Add in a cam with high valve overlap (like the Hotcam) and you'll defintely trigger P0300 codes (Random Engine Misfires) at manifold pressures under 40-45kPa (at least on my logs).

What does this mean to you? We'll if you happened to have an M6 tranny, all it would do is set off a code. It wouldn't affect anything else.

But if you have an A4 then the misfire detection, when triggered enough, will keep the torque converter from locking up until the PCM has seen a period of time with no more misfires. I'm currently working on trying to rid myself of this problem.

There are a couple of options to eliminate the misfire detection. One is to send the PCM off to reprogrammer such as Ed Wright and have him delete the misfire detection programming. The other would be to purchase some reprogramming software and do it yourself (such as LT1 Edit). Unfortunately, LT1 Edit cannot do this at the moment. It can defeat a P0300 Misfire Detection Test and the associated SES but it doesn't affect the actual MisFire Detection.

LS1 Edit does have a feature to alter when MisFire detection will begin to function (through temperature settings). And I've requested the makers of LT1 Edit to include this feature. They (LT1 Edit fellows) have not responded yet.

The last and most tedious route is to tune the engine well enough at idle/low MAP values to reduce the misfire counts. That's what I'm working on now.

The main point is that a Hotcam and a '96 A4 will most likely experience some torque converter lockup issues. You can end up learning how to "drive around it" but it's still an annoyance.

 

John... if I dont plan to run full on drag slicks... only steert tires would you recommend changing the 2.56 gears in the dana 36 or spenf the extra 700 and installing a dana 44?