Won't rev past 3000rpm.

Anonymous · Post by **Anonymous** » Wed Jul 15, 09 8:25 pm

That's a nice grind you have there Gringo.

That cam is ground with a 110* lobe sep , install 4* advanced (106* intake centre line)

Before you remove the cam set the degree wheel up & find out exactly where the cam is degreed @ the moment , could be a bad grind but i doubt it , or possibly the cam has slipped a tooth or a mistake was made when it was installed.

For a quick check pull the valve cover & get #1 piston @ TDC ex stroke , #1 intake/ex rockers should be around the same lift bearing in mind the opening/closing point with 4* advance , this will give you an indication the cam has been installed somewhere near the mark.

Gringo · Post by **Gringo** » Wed Jul 15, 09 8:44 pm

Brutus, it's most likely I've made a mistake on install. However, the Summit timing gear had some extra markings on it that caused some confusion. I lined up what appeared to be the 'dots', but I was dubious about the markings on the crank sprocket. The crank sprocket could be fitted in several positions on the woodruff key (that's the word I was looking for earlier

), and I'm not convinced the marking I chose was correct. It would all make sense though...

Anyone local who can degree a cam??? I ain't got a clue...

Anonymous · Post by **Anonymous** » Wed Jul 15, 09 8:52 pm

The crank sprocket will have three different positions , any one of those positions should not make the motor act as you are describing , as it only advances/retards valve timing a few degrees.

Good luck Mark , hope you sort it.

Gringo · Post by **Gringo** » Wed Jul 15, 09 9:03 pm

Thanks Adam. And thanks for the help and advice...

Guy · Post by **Guy** » Wed Jul 15, 09 9:04 pm

Isnt Kiwi nr you Mark??

Gringo · Post by **Gringo** » Wed Jul 15, 09 9:10 pm

Guy wrote:Isnt Kiwi nr you Mark??

He is, but I spoke to him earlier and he didn't seem to be much more knowledgable than me (no offence Kiwi), when it comes to degreeing a cam.

Anonymous · Post by **Anonymous** » Thu Jul 16, 09 1:27 am

Gringo wrote:
Guy wrote:Isnt Kiwi nr you Mark??
He is, but I spoke to him earlier and he didn't seem to be much more knowledgable than me (no offence Kiwi), when it comes to degreeing a cam.

Dave-R · Post by **Dave-R** » Thu Jul 16, 09 9:16 am

I would seriously doubt it has anything to do with the cam. If it was THAT far out you wouldn't need a degree wheel to see.

Take the #1 cylinder up to TDC on the EXHAUST stroke. Then rock the crank a few degrees either side of TDC and look at the lifters. You should see the exhaust closing and the intake opening points with some overlap at TDC i.e. the exhaust is not quite completely closed and the intake slightly open.

With hydraulic lifters you will have to look at the lifters themselves to see this so you will have to remove the intake. With solid lifters you can just watch the rockers.

The point where the lifters are equally just off the bottom should be TDC within 3 degrees.

But like I say. I doubt it is the cam. You will probably find it is something daft that will make you kick yourself. Like the carb not opening fully or something stupid like that.

Dave-R · Post by **Dave-R** » Thu Jul 16, 09 9:18 am

Sorry Adam. Just realised you already covered this.

Gringo · Post by **Gringo** » Fri Jul 17, 09 8:24 pm

Ok, on further investigation, as I've installed a new cam, it would appear that I should've checked the pre-load on the lifters...

Funnily enough, it says in the literature that too much pre-load will cause very low manifold vacuum...

I'm off to check tomorrow. I'm guessing if the pre-load is too great, I'm going to have to source some shorter push rods?

Does this make sense to anyone who has followed this thread?

challenger · Post by **challenger** » Fri Jul 17, 09 8:32 pm

or go adjustable rocker route, i brought some isky iron adjustable off dunc and aint looked back since, or another way is adjustable pushrods, think hauser might stock them

Cannonball · Post by **Cannonball** » Fri Jul 17, 09 9:37 pm

got another set for sale as well jim,

Dave-R · Post by **Dave-R** » Fri Jul 17, 09 9:37 pm

You have about a half inch of lift with that cam. Adjustable rockers are needed from this size cam and over. Highly recommended below this point.

Gringo · Post by **Gringo** » Tue Aug 11, 09 8:13 pm

YEEHAW! Finally got the problem sussed out. It's all down to Kiwi mind you. He suspected cam timing, after doing a couple of tests. Stripping down revealed the timing out by 4 teeth. My fault. Although in my defence, it wasn't clear as to how the crank sprocket mounted. I lined the '0' up with the keyway, whereas it should have been off set. Oh well, you live and learn. At least now if someone comes up with the same problem, we know what it is...

The good news is I should make the Hot Rod Drags, and get to run it up the strip for the first time.

And Jim, forget the 3.91's, and give us a chance! Oh, and don't forget the two second head start...

challenger · Post by **challenger** » Tue Aug 11, 09 8:21 pm

that old charger should pick its feet up now mate, dont forget to put the jetting back to how it was, glad its getting sorted its damn frustrating when things dont go right, as for the strip you never know i might just pull a cherry

so you wont need any headstart