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Posted

This could be one for the experts...

 

I've recently fitted a new cam it's a works 76 high lift. Yesterday I fitted bigger lash pads to get a better wipe pattern, reset valve clearances and now the car won't start. Again. Lol.

 

The old 74 was very forgiving, I basically put that in with my eyes closed, never dialed in and it ran fantastic. This 76 seems to have a very very narrow window of operation.

 

Is there anything I can do with very basic tools to get it going so I can drive somewhere to get the cam timing done properly?

 

Posted

I did turn it over by hand after fitting the bigger lash pads, It was all free and nothing was hitting.

 

I'm only two mins away from Lou Mondello's shop, I could almost push it there!  ;D

Posted

It almost fires in the first 5secs of cranking. I'm thinking that the cam timing wasn't right before and now the bigger lash pads have changed the timing further, pads are 50thou bigger to get the pattern dead centre of the rocker.

 

I dont have a comp tester  :( Are the exspensive?

Posted

About $20 from super cheap. You'd be surprised how much you'll use it.

I compression check every motor I buy now.

Posted

Check the cam timing is close...you should be able to get it started. Double check your ignition timing, you may need to advance it some to get the car started, or you may be 180* out.

 

If the car is carburated, it sounds like you are flooding out...the cam can't handle that much fuel on cranking. Check the chokes to be sure they're shut. Rule this out by pumping the throttle...if it gets better and starts, it was too lean. If it gets worse and floods, it was already too rich and the problem got worse.

Posted

What change/increase in lft at valve?

What was valve to piston clearance prior?

 

A slow hand rotate may have been ok, just, but on a brief higher rpm start up, and if cam timing to crank isn't quite right,,,,,,,

You may, just may, have kissed valves to pistons,, only takes a couple thou to bend the heads!

Posted

:-[ Oh no, Here I was thinking I could just change them out. Insert massive face palm here!

 

Xnke, it did smell like it was flooding after a few seconds. The other problem is I run a small battery to save weight on track, this doesn't help with repeated cranking. I usually only get 3 long cranks before the voltage drops off a lot. Only a problem when the village idiot(me) has been tinkering.

 

Jason, A+B I have no idea  :-[ I find cam timing very difficult to understand, it may as well be written in a foreign language. With my limited tooling the intake was opening at 25btdc which is correct according to the spec sheet.

 

Pete, I'll give you a ring tomorrow.

Posted

It's Fixed. Runs smooth and pulls like a train  ;D I was very lucky that Pete came down to check it over and he had it going in no time at all. Thanks mate, without you it would've been completely stuffed!!!

 

Somehow I had managed to screw everything up, the cam timing was wrong, the lash pads didn't need to be changed and I had even stuffed up the valve lash

:-[

Posted

Gareth to call your self clueless is so harsh , your car is a real head turner and the way you have made it your own is stunning , top job man  8) 

keep trying and you will get the skills, it takes years to get the know how , you have done a better job than many pros .

Mya is hard, one day i may have the skills to be as good as her ... ::)

Posted

+ 1 for Peter . He knows you can't fix that one over the phone. Well done Peter . Gareth, you are one lucky man.

Posted

Check valve heads to stems, doesnt take much force to bend them a couple thou.

New valves now!

 

I have had valve heads "droop" a thou or two from shutting down a very hot engine, where a valve was open!

Posted

It's under a cover now, I turned off the lights, backed away slowly and was careful not to make eye contact!  ;D A mans got to know his limitations! 

 

Would it run ok with bent valves? it's smoother than the old cam down low, probably cause it was set up properly. Idle isn't lumpy at all.

 

I still owe you Pete!

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