top end rebuild....

[speedskills]

I just busted the timing chain on my 87 GN. Does anyone have info on a good streetable cam/head combo. I'm trying to retain the stock heads because of a tight budget right now. I'm looking for a budget build. Any help is greatly appreciated.

 

[chadly]

How many miles are on the car and what are your goals? If your on a budget it may be wise to just replace the chain for now and build what you want later. It sucks to do/pay for things twice.

 

[speedskills]

The car has 75k miles and I would like ot to run 11-12 second qtrs.

 

[chadly]

The car has 75k miles and I would like ot to run 11-12 second qtrs.

Add the alky and you've met your goal. On a budget you could get a chain and valve springs for close to a couple hundred bucks. Add the alky kit and you’re in the 11's. Chain, valve springs, and alky will be cheaper than just a roller cam.
If you’re going to do the heads and cam I would do the short block as well. I was on the board a few years ago with the same thoughts as you with doing the heads and cam. I ended up just doing the chain and adding alky as recommended. I run 7.6 in the 1/8 24 psi which is roughly 11.8 in the quarter. I saved my money that I would have spend on cam and heads and bought a long block to build on the side. Just my 2 cents.

 

[williambavila]

Add the alky and you've met your goal. On a budget you could get a chain and valve springs for close to a couple hundred bucks. Add the alky kit and you’re in the 11's. Chain, valve springs, and alky will be cheaper than just a roller cam.
If you’re going to do the heads and cam I would do the short block as well. I was on the board a few years ago with the same thoughts as you with doing the heads and cam. I ended up just doing the chain and adding alky as recommended. I run 7.6 in the 1/8 24 psi which is roughly 11.8 in the quarter. I saved my money that I would have spend on cam and heads and bought a long block to build on the side. Just my 2 cents.

x2

 

[speedskills]

I really appreciate your help, but I may have jumped the gun. I haven't tore the car down yet to be positive its the timing chain. What happened was about 3/4 way into the throttle there was a small pop then a loud backfire then no start. I pulled cam sensor cap last night and noticed cam sensor not turning. I have no spark. Engine sounds normal when I tried to turn it over. Am I on the right track?

 

[Nick Micale]

If you did break a timing chain, please e-mail me direct details about the chain set, cam, valve springs and and other info as we are working on a stronger chain set to help solve this problem.

So far all the broken chains have been on higher HP and RPM race engines.

Over the past few years I have trashed 4 chain sets, 2 of them broke chains that bent all the valves, and know of other racers having done the same.

 

[Nick Micale]

After reading your last post where the cam sensor is not turning, the roll pin on the cam sensor gear may have broken. Pull the cam sensor to verify first.

Loud backfire would do it - been there done that too!

 

[speedskills]

Thanks for the help yall. Time permitting I'm gonna pull the timing cover and cam sensor tonight and let you know what I find. If you break something there is always room to improve, right?

 

[chadly]

Do as Nick has sugested and just pull the cam sensor gear out. Just one bolt to pull. this will save you lots of time. Pulling the front cover takes some time. Atleast for me.

 

[speedskills]

Well guys, Nick hit it on the head. I have a sheared pin on the cam sensor and the cam sprocket lost all its teeth to the oil pan. Nick I think everything is stock(cam and timing chain). Hopefully that is the extent of the damage. Thanks for your help. Let me know if yall get a better timing chain set, Nick.