-
04-16-2011 06:40 PM #1
low oil pressure, cam specs for 305?
Pressure seems okay when warming up but drops when it is fully warmed up. I can't hear any knocking, no metal in the oil, and the oil pressure gauge is good. My problem is when I bought the motor the guy said it was a 350 with maybe 9k miles (said it was a crate motor, but I'm not so sure now). I finally looked up the numbers on the block and it turns out to be a 305. I really don't care about that part but I put a beefier cam in it (thinking it was a 350) and am wondering if I have too much lift for stock 305 valves, rocker arms, push rods etc. Any ideas? I'm going to cut open the oil filter tomorrow and see what's inside.
I put a Mellings cam with the following specs:
Cam Lift
INT. .298
EXH. .298
Valve lift
INT.447
EXH. .447
Lobe CTR
INT. 110
EXH. 118
Lash Hot
INT. HYD
EXH. HYD
SAE Duration
291 INT.
291 EXH.
.50 Duration
223 INT.
223 EXH.
SAE Timing
BTC 30
-
Advertising
- Google Adsense
- REGISTERED USERS DO NOT SEE THIS AD
-
04-16-2011 07:14 PM #2
That's way more cam then a stock 350 could use....Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
-
04-16-2011 07:28 PM #3
My father in law used to race chevys and said it shouldn't be a problem... but I might be doing a cam swap again.
Is it a good chance the cam bearings are worn out now? Wouldn't I be able to hear any knocking or anything if it were the bearings?
-
04-16-2011 08:02 PM #4
Probably wouldn't be a problem....if it were a race engine, but it's just a wheezy little 305 with a long stroke and a peanut sized bore.... A stock 305 doesn't need near that much duration or lift.... Might want to check Comp Cams and download their Cam Quest program (it's free) then punch in the real information on your engine and see what they suggest....
A too big cam won't hurt cam bearings, if the valve springs haven't been in coil bind, or the valves haven't hit the pistons, a simple cam change would be in order. Guessing what the bearings look like would be just a guess...when you're changing cam and lifters, check the pushrods for straightness and all the other parts in the valve train for excessive wear...
If you want your new cam to last, make it a roller cam. Today's oil just isn't up to the task of lubricating flat tappet cams in a manner that will promote a long life!!!!!Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
-
04-16-2011 08:11 PM #5
Thanks for the response. I guess I'll just be swapping cams... That sure as hell beats pulling and overhauling the motor.
Thanks again.
-
04-16-2011 09:49 PM #6
You may be doing that also. Worn rod and main bearings contribute to low oil pressure.
I'm not trying to belittle you, but let this be a lesson to you. Never, never, never, never, never take anyone's word for the condition of a motor. Never. There are no honest people left on this rock. If you can't inspect and measure the individual parts for yourself, walk away.
The S.O.B who sold you this pig needs a blanket party.PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.
Welcome to Club Hot Rod! The premier site for
everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more.
- » Members from all over the US and the world!
- » Help from all over the world for your questions
- » Build logs for you and all members
- » Blogs
- » Image Gallery
- » Many thousands of members and hundreds of thousands of posts!
YES! I want to register an account for free right now! p.s.: For registered members this ad will NOT show
Merry Christmas ya'll
Merry Christmas