Moparts

HELP needed

Posted By: sixpakx

HELP needed - 08/24/15 06:51 PM

sorry so long, not as sharp as i use to be, my son n law bought a 71 rr 383, big big can and no coverter(dies when put in gear)heads shaved with shims under rockers, so we ordered a 284 cam, bought a set of rebuit 906 heads from indy( i know).yesterday i took it apart and sure enough shimmed, pass side rocker shaft holes was at the top(upside down), and i noticed 15 0f the push rods have holes thru them like chevys, motor was very clean, got it back together and set the rpm,s @ 3500 for 15 minutes, then dropped it to 950. noticed it had 10 psi oil pressure(aftermarket mech gauge) don,t know what it was before we took it apart, racing eng it moves very little, would these open push rods cause this? and what kelp it from blowing up? i,ve only saw solid push rods in stock eng, again sorry but any help needed
Posted By: Supercuda

Re: HELP needed - 08/25/15 01:26 AM

Unless the lifters have oiling holes too, then it's not an issue.

If the lifters do, then possibly that is your issue. 10 Psi is on the low side, but still above spec, barely. What weight oil are you running?

I prefer to run 10w30 myself.
Posted By: sixpakx

Re: HELP needed - 08/25/15 03:39 AM

we put in a new hyd mp 284 cam, it came with lifters, we used castrol gtx 20w50 oil, I know it can,t live long on that pressure, thanks for your reply, anyone else got any ideas, 70 something lookers, think this might have ppl scratching there head
Posted By: Supercuda

Re: HELP needed - 08/25/15 04:51 AM

At 20w50 I'd expect to see more pressure at idle, unless you have some real loose bearing clearances. Sorry I can't offer more.
Posted By: sixpakx

Re: HELP needed - 08/25/15 05:15 AM

thanks, im going to change the push rods to the solid ones, I never watched the oil pressure during cam break in, don,t see how it stayed together
Posted By: calrobb2000

Re: HELP needed - 08/25/15 05:18 AM

hi
any chance the fuel pump is putting gas in the oil ?

bad diaphram ?
Posted By: poorboy

Re: HELP needed - 08/25/15 07:09 AM

Mopar always stated the 10 lbs oil pressure per 1,000 rpm was enough. I've had some motors live a lot of miles on 10 psi when they were at hot idle. That said, it usually left me being a bit nervous.

A lot of low oil pressure problems were caused by excessive cam & rod side clearance. Gene
Posted By: sixpakx

Re: HELP needed - 08/25/15 03:53 PM

we changed the oil before we fired it up after the cam change, understand the clearances, this engine looks new inside, all the gaskets was reusable except we did replace the head gaskets and valley pan, anyone ever have push rods with holes in a 383?
Posted By: feets

Re: HELP needed - 08/25/15 03:59 PM

Start the engine again. Does the oil pressure go up with rpm?

If so, hop in and hit the road.

If not, dig into it to find the problem.
Posted By: sixpakx

Re: HELP needed - 08/25/15 04:25 PM

yes to about 15 lbs @ 3500 rpms
Posted By: RapidRobert

Re: HELP needed - 08/25/15 05:06 PM

What Feets said & 15 (confirmed with a good gauge) ain't gonna cut it. not sure where the prob is but I would definitely dig in. not sure if the additional flow from the oil thru pushrods is the cause or not (I'm thinking not) but that (might) be the first thing I'd swap & check further on that situation (& check preload while you are at it but that is unrelated to the psi).
Posted By: sixpakx

Re: HELP needed - 08/26/15 02:51 PM

changed push rods, now got 50 psi @ idle cold, thanks for the help
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