I was wondering if any of you who have had experience with the LT4 hot cam could answer a couple of questions. I'm curious to see how you feel the cam affects reliability. I'm speaking specifically about starting and idling (I.e. does it idle rough). Also, is there a noticeable "lope" to this cam?

Thanks!!!

Scott

 

I had that cam in my 95 6-speed LT1 car. You could just barely tell there was a cam in it. It idled nice only a slight lope if any. It started right up allways. I have the Hot cam kit to install in the GS already. It will go in over the winter. My times with the 95 are in my sig. I only got it to the track once.

 

You'll need to idle a couple hundred rpm higher and you'll need a reprogramed chip or PCM to make it run right.

 

Installed my in my Dad's LT4. It idles great. I did not have to do any reprogramming of the ECM. It has yet to set any trouble codes. Also did some full throttle datalogs and it showed good numbers for spark advance and O2 sensors.

I almost think that maybe the LT4 computer was designed with the hot cam in mind, as I did not experience any of the problems that LT1 guys have (rich idle, surging, etc).

 

RichS,
I am doing the mods listed in my signature under (in progress) and have the mods under (current) in my signature. my question to you is when you were turning those impressive numbers with your 95 which is what i have, were you similarly modded? i am really excited about this upgrade to my Vette and just wanted to speak with someone who has done it and you had the 95 like me and i figured hey i will ask Rich!! so is there any little hints you might be able to throw my way to help use the new cam and work im getting done? if so you can post it here or even send me an email at lcvette1@aol.com
I LOOK FORWARD TO TALKING WITH YOU!

THANKS,
CHRIS :D :D :D :D :D :D :D :D


[Modified by lcvette, 10:26 AM 8/7/2001]

 

Hmmm Maybe the LT1 ECM deals with change a bit better, but the 165 (86-89) definitely doesn't run right with a hotter cam - they are MAF systems also. I can guarantee that your stock fuel and timing curves won't be optimized.

 

i have/had this cam in my '94 lt1.. there is a little lope to it, basically your car will sound a little healthier than stock.. of course lope is pretty much only heard at idle, so it depends where you set your idle at too.. i changed my idle from 750 to 800rpm when i had it reprogrammed.. you won't need to go "a couple hundred rpm higher" or anything tho..
as with any performance mod to the engine, tuning is always crucial to extract the most power for your combination.. the car is plenty driveable without the tuning, but i still recommend it. no mail order programs tho.. take your car to the tuner..

 

how about Ed Wright? he seems to be a little more detailed about how he sets up the program for a modded car. i suppose maybe More Performanmce in Charlotte could do it on a dyno or if the new dyno in raleigh has reprogrammable capabilities i could take it there i suppose. i had alweays assumed i would use ED though. please give me more input on this subject as i am wating for one last email from Jeff on my hotcam kit before i place the total parts order, i need to start investigating where will be the best place to get it dialed in with the computer!

thanks guys,
chris :smash:

 

I will probably be going with the LT4 HOT cam when I rebuild. I will definitely be taking the vette to Ed Wright when I do it though. It's too bad his dyno tunes run like $500-600 though. I'd much rather do it for $350 (like his normal tunes), but I'd also rather let him work with the car as well rather than a template.

 

Chris, The car had Ported stock heads with bigger valves by Morgantini racing(flowed awsome!), Hot cam kit,LT4 extreem duty timing set, ported intake, Holley 52mm TB, DRM longtube headers with no cats to a Corsa system. Votex rammer, MSD box, MSD coil, taylor wires, NGK plugs, Ed Write reprogram, LT4 knock module, 4:10 rear, and a short shifter. All else was stock The runs were made on Drag radials. On street tires I ran 12.5 but forget the MPH then I got the GS. I plan on doing all the same things to the GS and am hoping for 11's in nice weather, low 12's normal weather. Any other questions just ask


[Modified by RichS, 5:37 PM 8/7/2001]

 

Rich,
sounds god, i am no far behind you on my mods, i wil most likely be caught up by christmas tme with what you had on your 95, those times look seet, i a geting very anxious! my dad is doing the same thing to his LT4, its going under the knife next thurday so i ill be able to give yu some numbers as well. gosh this forum is great isn't it! takes alot of poorly spent money from guess work out f the equation! ok, i do have a question or you, i am planning on going with the thinner head gaskets, did you take his route? if so were there any cearance concerns with te new lift geometry such as piston to valve clearance? or coil bind? i need somefirst had eperience with someone who has used te thinner gaskets with thi approach of the hot cam kit, i would hae to wipe out all this work due to bad planning. anyways i look forwardto your reply as alwas Rich! thanks a mllion!

Chris :smash:

 

Cartek did my PCM ON THE DYNO, they have the programing.
Its working for me, give Julio a call.

 

My heads were shaved just a little to make sure they were true. They cc'd about a 1/2cc less. I then used normal thickness Felpro gaskets.

 

thats a point i had not yet thought of! i am hoping my heads will not need to be milled, i am in design an i alo have my formal training as a Suzuki Mechanical technician, and while in school, we learned about squish area and how it effects combustion and cylinder temperature dynamics. the aount you shaved yours im sure was negligible im certain and of course they were done by highly experienced professionals. but just fyi, because i know itwas a big ordeal t have your heads milled in the past, as you depleat the squich area or lip of the cylindeer head, you take away an integral part of the combustion chambers ability to maintain consistent burn temperatures. by depleating them, the temps will raise considerably causing ideal conditions for detonation an loss of power. subsiquently your cylinder pressure will be substantially higher due not only to the extra generated heat but also to the fact that the compression ratio is higher, this is a double edged sword, done right you can draw fantastic gains, but after a certain point you will not only make less power but begin to destroy pistons, valves, etc.. yours i would say is an example of a job done right! anyways, just a tidbit that i thought of when i read the post. :D again im no that smart to have concieved that theaory i just remember what the tech instructors were saying very well :D ok, im off to find more info on this heads gasket mystery, and Rich thanks again for you experience and wisdom if you think of aything else i might use with this package let me know!! i am all ears :bigears :lol: i crack myself up sometimes!!

thnks aga
chris

 

One thing that hasn't been mentioned is that (I'm pretty sure) that the LT4 engine has a higher idle (mine idles at almost 1000rpm) than the LT1, so it idles better with the hotcam.

 

My LT1 idled at 950 with the Hot cam. The same as with the stock cam. My factory tach was off a little also.

 

David F and I played and tested numerous LT4 with the "hot cam". Most had a slight higher idle over the LT1/LT4 stock cars. So far reliability has been very good.

The "hot cam" itself was to be the original cam for the LT4 stock street model but due to the mileage requirement through the entire line of corvettes and Chevy cars, it was decided that this would not be the best way to go. The different maybe small to us (one to three mpg less depending on driving habits) but when measured into the entire production line mpg numbers helps to meet the required EPA numbers.

So far, no one has failed emission tests in any of the 50 states.

Horsepower gains vary from car to car but average range seen comes in between 28hp to 38hp on a stock LT4. The improvement is noticeable in the mid to upper rpm range.

Good option for the money......

Stan A :chevy