I just learned that I have a Summit 8600 cam

[AwesomeJ10]

I'm in the process of a GM TBI 7747 conversion on the J10 Honcho. It's been built, rode hard and put up very wet. AMC 360.

Got the TBI installed, started out with a BIN from Scott (thanks sroberts!). Did a little data logging.

Still idles like crap. Run great.

Did a little searching and kept reading threads about how bad the summit 8600 cams are.

Ouray is just over a month away. I'm driving it. Not towing.

What should I do?

[AwesomeJ10]

I bought this engine from a guy on Craigslist. He built the engine and ended up moving. Sold the engine to me before completing the build. He even came over and personally got it running. Great guy and seemed to know A LOT about AMC engines. I found the receipt from when he bought the cam.

I've never been able to get a good idle....

[ScottsMojo]

Admitting you have a problem is the first step of recovery...

Now you know, and you understand that its just not right to continue to let that half-breed cam bump valves! [-x

[Stuka]

So it has never idled well even with the Truck Avenger? Just want to make sure its not an issue with the TBI itself, but rather with something in the engine.

I have never had a K8600 before, my old Cherokee still had a stocker cam in it. But from what I have read over the years is that at one time, people loved the K8600. At then at some point, people started to have more and more issues with them. But the issue was typically with them going flat. I think this was about the time that Crane Cams went under. Crane used to make Summits cams (The packaging, specs cards, everything was identical). I am not sure who makes them now. But it seemed there was some point in there where lots of people were getting cams that either were not ground right, or went flat. Whether that has any bearing on yours or not, who knows. But thats probably where you hear that their cams suck.

If you suspect its the cam, it could mean the grind is a bit more aggressive than it should be, is simply wrong, or the cam was degreed wrong and/or too advanced. Does it sound like the engine has a lope at idle, or does it actually sound rough and/or misses?

[AwesomeJ10]

I was able to get a 'decent' idle when the motor was still very freshly built using the Holley TA 670.

But then, right about the time it took a swim in the lake, it's never been the same. I went through the carb several times and I'm 100% sure all the passages were clean and clear.

So then I decided to put the TBI on there. It idles rough. Very rough. Sounds bad.

Tonight, I was sitting there playing with the BIN using tuner pro and added some idle timing, messed with the closed loop idle settings, etc. burnt a chip and started it up. Idled much more smoothly. Only ran it for a few seconds, then shut it off.

Now it won't start! WTF.

I'll mess with it tomorrow....

[AwesomeJ10]

Does anyone on here know how to 'tune out' a bad idle with a summit 8600 cam?

[Stuka]

What RPM do you idle at? The Summit cam does have a bit of a lope at idle, more noticeable with manuals since they idle lower than autos.

[AustinAubinoe]

sorry to hyjack, but who makes "crane cams" now????? I always thought of them as the best! What I planned to buy for my future all out non original rig.

[Stuka]

sorry to hyjack, but who makes "crane cams" now????? I always thought of them as the best! What I planned to buy for my future all out non original rig.

S&S Cycle bought up the majority of Cranes assets, including the name, some patents, and so on. From what I had heard at the time it was for the better. Cranes manufacturing plant was pretty out dated, which is why they were not as competitive. Their cost were higher.

[jaber]

There have been several guys that have had great success with the Lunati Voodoo cam. I have been running a Comp Cam for 10 years with great results. \:D/

[lindel]

I believe that S&S is making the Summit cam. I've had a couple and had decent results out of them, but that was many years ago.