need tuning help !!!!!
Thread Starter
Pro
Joined: Jan 2003
Posts: 669
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From: memphis tn
need tuning help !!!!!
heres what i have.
performer rpm intake
eps 800 carb
performer rpm cam
specs:
.308 int .318 ex @ .050
.490ish int .510 ex lift
new hei distributor
max timing @ 37*
vortec heads.
ok, my problem is i cant get a stable idle to save my life. i can have it set perfectly, walk away and it'll either die or crawl up to 1500rpm's. i have the lowest vacuum metering plunger spring in the carb. my idle timing is not stable either. ( could it be getting into advance and messing w/ the idle?)
another thing that has me worried. i just changed my post cam break in oil. noticed a lot of metal in it( looked like fine glitter in the sun). its been so long since i've used a flat tappet cam. is this normal ? i would think not, but what do i know.
performer rpm intake
eps 800 carb
performer rpm cam
specs:
.308 int .318 ex @ .050
.490ish int .510 ex lift
new hei distributor
max timing @ 37*
vortec heads.
ok, my problem is i cant get a stable idle to save my life. i can have it set perfectly, walk away and it'll either die or crawl up to 1500rpm's. i have the lowest vacuum metering plunger spring in the carb. my idle timing is not stable either. ( could it be getting into advance and messing w/ the idle?)
another thing that has me worried. i just changed my post cam break in oil. noticed a lot of metal in it( looked like fine glitter in the sun). its been so long since i've used a flat tappet cam. is this normal ? i would think not, but what do i know.
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: need tuning help !!!!! (neverendingproject)
I'm sure someone with substantially more experience will chime in soon, but the first time I had them, my wandering idle problems with a Performer 600 cfm were caused by a vacuum leak. A new carb gasket cured the problem.
The next time I had them (after misreading a stamping on a primary jet), the engine would idle high, then slowly drop until it almost died, then as it started to sputter, it would suddenly jump back to 1500 rpm and start the cycle again. I found that the jet/rod combo was way too lean, causing the engine to lose speed, until it could no longer stay running. Just as the engine was dying, the vacuum would drop so much that the weak step-up springs pushed the metering rods into the power (narrow diameter) position, giving the engine a drink of fuel, causing the RPMs to jump, starting the process over.
Good luck with the cam issue-- I can't help you there, other than to say that I don't remember any metal shavings in my oil after I swapped mine.
:cheers:
The next time I had them (after misreading a stamping on a primary jet), the engine would idle high, then slowly drop until it almost died, then as it started to sputter, it would suddenly jump back to 1500 rpm and start the cycle again. I found that the jet/rod combo was way too lean, causing the engine to lose speed, until it could no longer stay running. Just as the engine was dying, the vacuum would drop so much that the weak step-up springs pushed the metering rods into the power (narrow diameter) position, giving the engine a drink of fuel, causing the RPMs to jump, starting the process over.
Good luck with the cam issue-- I can't help you there, other than to say that I don't remember any metal shavings in my oil after I swapped mine.
:cheers:
Thread Starter
Pro
Joined: Jan 2003
Posts: 669
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From: memphis tn
Re: need tuning help !!!!! (neverendingproject)
as i was typing my post, i answered my own question. the new distributor had very light advance springs in it. since it needs to idle around 800-850 rpms, it was advancing and raising the idle speed. when i adjusted it back down, it would come off the advance and idle down till it died. :crazy: i knew better than that.
as far as the metal shavings, i dont know if you could call them that. if you didn't look at the oil in direct sunlight you couldn't see it. some people may not recognize it then. i guess i'll know in a few more oil changes.
as far as the metal shavings, i dont know if you could call them that. if you didn't look at the oil in direct sunlight you couldn't see it. some people may not recognize it then. i guess i'll know in a few more oil changes.
Advanced
Joined: Sep 2003
Posts: 59
Likes: 0
From: McKinney TX
Re: need tuning help !!!!! (neverendingproject)
Fine Glitter is usually bearing material. It depends on where it comes from on whether you have a problem. Sometimes when an engine is assembeled the Rods are not perfectly square in the bore and the sides of adject rods rub together for a little while until they straigthen themselves out in the bore. I used to run 20 thou clearence between rods on my race engines and would keep a 20 though feller gauge between the two rods and rod caps while I tightened the rod bolts. This would keep the rods square. If its a matter of the sides of the rods on the big end rubbing together this will soon stop and the glitter will stop. If its not the sides, then I'm afraid you have a bearing that did not have enough clearance or lubrication. Both of these conditions can also clear after a a few minutes of engine run. If the problem persists, you need to drop the pan and check the bearings.
