Crate engine cam timing off?

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mguner

mguner

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I am working on a friends 68 Barracuda with a Jegs 408 magum with a 274/474 cam. It sounds pretty salty but is an under performer. It been to a couple of shops and they haven't figured it out. Aside from it having a loud rattle in the heads, to get it to run decent the timing shows 45 degrees initial! This is with my old Snap On dial light. Stock type electronic ignition conversion with the single ballast. Is 45 degrees an indication of it being a tooth off? Rattle may be pistons chasing valves closed?
 
Degree the cam, we are all human including the line workers. As for the head rattle...? Yeah, I'd be looking into that too.
 
you cant assume anything....start from scratch if you have to...degree the cam and check the mark on the damper {or make your own} so you can time it correctly. I even check the cam firing order, some cams have a 4 and 7 swap in the firing order. {mostly relegated to chevy though}. You would think that you wouldn't have issues with a crate engine but....yes make sure the cam is lined up correctly with the crankshaft,{gears line up, crank to cam} mistakes can be made...
 
First, throw that dial back POS in the ditch. Get an old NON dial back inductive timing light and take another reading. Unless that light is a digital dial back, there are WAY too many variables that can make it read incorrectly. Yes, even with Snap On. instead of being fancy, just let the engine be its own dial back. It's the most accurate in any case.

Secondly, as others have said, degree the cam. Nothing like makin SURE the cam is installed correctly.

Once that is done, give it a good hot ignition timing curve. "around" 20* initial and all in by "around" 2500. All that will wake it slap the hell up.
 
Howard1784 said:
Jegs 408 is a Blueprint motor if I am not mistaken. Problems, problems and more problems.
Click to expand...

i know plenty of folks running BP motors with zero problems. One my brother, and one my neighbor running a bbc in his boat. Its a BEAST.
Please elaborate.
 
So why hasn't it been returned?
If I bought a motor that rattle and didn't run right it would go back so fast it would probably still be warm when the got it back.
 
skizzo said:
i know plenty of folks running BP motors with zero problems. One my brother, and one my neighbor running a bbc in his boat. Its a BEAST.
Please elaborate.
Click to expand...
Not 100% fail. Neither are 100% balanced perfectly, degreed perfectly or blueprinted perfectly. I dont mean to poke a stick at ya, but there is a difference between a builder and an assembler. There is a reason that engine costs as little as it does.
 
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Find true TDC, then degree the cam to see where it's at. Compression test??? Go from there...
 
Check to make sure the pick up coil is not reversed . The timing suggests it. I jus had to reverse the wiring on mine.
Sounds like the exact same problem I was having.
 
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