Hello to everyone.New to the forum.Want to say this is the best one i've seen.Done a search first but had no luck.I've got a fresh 383 in my 89.Got the cc305 cam in it.Can someone tell me were to start with intial timing on this cam?

 

6* is stock for a TPI, that would be a good starting point until you get everything right. I have seen people run as much a 10* but you have to run higher octaine gas and watch out for knock.


Brian Felts

 

I'm running hsr,slp 25lb injectors,slp 1-3/4 headers,@10.8.1 comp.,l98 ported alum.heads,cust.chip to get me started,stock 48mm tb,1.5 comp roller tip rockers.

 

I have one word for you TORQUE! Yeah I think you will have a good combo. The timing I run on my LT4 305 is about 8* with a stock chip. I run 16* on my carb 355. The alum heads will allow you to run with a little more timing than the cast heads. I think I would start out at 6 and get the motor up and running and then see how far you can go before you get knock then bring it back 2* and you will be safe.



Brian Felts

 

Thanks for the reply,i'll see if i can get it set this weekend.hoping for some good #'s at the track this spring

 

I run a CC XR276HR-12 in my 385, 224/230 .535/.540

22*@idle, the base timing is 6* and the rest of timing is brought in through the ECM. The motor idles fine with 22*, it runs within range of the ECMs correction capability. I will be remapping the spark tables to to give 24* total a try, just for kicks.

Factory spark tables suck!!! If you dont have a custom PROM the car will not run to potential.

 

I was assuming he was running a stock chip with my suggestions.



Brian

 

Just run the stock timing and make your changes in the chip.

 

Right now i have a custom chip from pcmforless.I will be looking into getting all the stuff to do my own.I just needed one to get started.My timng is jumping all over the place right now.Will prob. have to pull timing cover to put a cam button in.Engine builder fail to put one in.I believe i'm getting some cam walk.does anyone how i can check to see if this is the problem?alot of work to do for nothing.

 

The only way I know of to check it involves more work than pulling the timing chain cover.

It involves pulling the intake manifold, removing the lifters and using a soft tipped probe to see how much the camshaft can be moved forward and rearward.

If you decide to pull the cover, use the roller bearing type, not the solid type. I've seen solid types drill into the timing chain cover.

Hope this helps.

Jake

 

What year is the block? If it was a factory roller block you should be running a thrust plate.

 

It's a 88 model corvette block.It has a thrust plate.I ran through the rockers and it smooth the timing out.Strange what happens when you have a few to tight.I'm glad i don't have to open the motor up.I've got the timing at about 12* and it's runs pretty good right now.Going to have to do some more tuning.It just doesn't seem to have enough a** for what i have in it.Thanks for the replys.

 

Chances are that if the chip is not setup to recognize 12* as base timing you are going to be getting alot of detonation and then the knock sensor will be performing alot of timing retard under WOT, and everywhere else for that matter.

 

Thanks for the info ominous.I'll have to wait until i get my chip burner and software.