Jump to content
Sign in to follow this  
Thom

Cleveland oil supply mod

Recommended Posts

Ok here are a couple of photos of the oil supply mod you can do to any clevo ( except the new arrow blocks and blocks with a oil restrictor kit as they won't see any improvement ) to remedy the terrible factory oiling that supply the cam and top end first an leaves the crank to starve at higher rpm.

 

5asa5aqe.jpg

 

It's pretty simple all you do is remove the oil gallery plug next to the fuel pump boss and run a line ( can be hard ot flexible, i personally prefer hard line) to the oil pressure sender at the rear of the engine with a t piece so you can still run and oil pressure switch, what this does is prioritize oil supply to the crank first so you done end up with rocker covers full of oil and a starved bottom end.

Share this post


Link to post
Share on other sites

this works ok, i still like changing the pressure releif spring in the oil pump though.... 80psi spring makes it safe to roughly 7500rpm, anything above that is a bit of a guess, should be ok to 8, but yeah who knows.

Share this post


Link to post
Share on other sites

That's a great simple mod Thom. Is that 5/16 or 3/8 Bundy tube? And are they just compression fittings into the block? We sell all that stuff at work so I reckon I'll be doing this mod soon. Good idea.

Share this post


Link to post
Share on other sites

I ran this oiling mod on a 460 BBF that was in a drag car.  The engine ended up throwing a rod but the interesting thing was that the damage to the crank was limited only to the journal where the rod failed.  Even with the loss of oil pressure in the system the bypass line kept oil to the rear of the crank.  It demonstrated how the bypass line helped even the oiling out from front to rear.  On the down side, I reckon we would have picked up the failed rod earlier if the bypass wasn't there - we would have seen the drop in oil pressure.  The bypass line effectively masks an oil pressure drop because it plumbs into the back of the motor right at the point where the pressure sender is.

Share this post


Link to post
Share on other sites

I’m bringing a old thread to life here does any one know the thread where the oil line exits the block near the oil filter? Is it 3/8 npt? 
 

any help would be appreciated, thanks scott 

Share this post


Link to post
Share on other sites

I purchased a Aeroflow 3/8 npt to -4 fitting for a turbo oil feed line, I recently had to remove this fitting to upsize to a -6 oil supply fitting.

 

When I removed the Old fitting I noticed the thread on the fitting wasn’t in good shape. Instead of the thread Pitch going up to nice sharp points it looked blunt does that make sense?

 

so before I purchase the new fitting I just want to be certain that it is 3/8 npt.  The factory grub screw winds in and out fine so it not cross threaded.

Share this post


Link to post
Share on other sites

Anything American will be NPT. Anything British or older Jap stuff will be BSPT. There is a 1 TPI difference between the two on most sizes. You can tighten the shit out of it to seal but will mash the threads. Maybe the fitting you pulled out was BSP?

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

Yeah I’m going to do a bit more research I think. I’ll take the grub screw to a few places tonight Hopefully some one can match it.

 

  I do remember holding the old 3/8 npt fitting next to the grub screw and the thread looked exactly the same. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×