xdclevo

Here's me thinking along the same lines, but with 7400 which is where the limiter is set
I recon it'll see 7000 safely for years.

__________________
10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

 

xbgt74

The saga continues...had the manifold machined to suit the valley..tried again still oil in the manifold...i was told that because i have the restrictor kit and high volume pump fitted and because i have a big overlap cam 275@.050 that the rocker breathers aren't coping and pcv valve which could cause this....next question is for anyone with a similar set up what type of breathers have you fitted ?....or maybe the oil rings are the problem?

russxr67

Piss the PCV valve off and run a set of -12 lines from the covers to a tank/s. Do this first and see if there is any change.
I don't use hi volume pumps becuase they are not needed on clevo's

xbgt74

Thanks for the reply....I disconnected the PCV and run a line of the rockers and left them "hanging in mid air" run the engine for a while ...very little coming out of rockers..took dipstick out and put thumb over hole to see if any blowing or sucking...practically nothing...tried changing oil to heavier grade and took it out for a thrash...oil pressure 65lbs temp...60 deg.c still blowing smoke.Gave it a few runs up and down the rev range ...2500-5500rpm check breathers...nothing coming out(very slight)took carby off...looked down runners and oil sitting on top off closed inlet valves....it used over a litre of oil for about 60 kms....i just can't figure how oil can get into the inlet manifold?It's driving me crazy trying to figure this out...could the oil rings be passing that much the compression rings can't handle it?Could the head gasket allow oil to pass into the inlet side?

russxr67

Sounds to me like a ring issue or more precisely a ring installation cockup.
Your engine still makes good power by the sounds of it and I think you can discount the inlet manifold after resealing . I would be inclined to pull the motor and check to see that the rings have not been installed upside down especially the second ring which is more of a scraper than a compression ring. It looks like that particular ring is not doing it's job of keeping the oil on the bore to a minimum and in doing so is managing to get past into the bore.
Diagnosing stuff like this over the net is hard to do but from what you described that is where i would be looking next as the other scenario's that you described are verging on the impossible.

xbgt74

I think your probably right....it is making good horsepower...I guess you have to try all options before you pull it out and start stripping ...Thanks for your input.

russxr67

Just had a brainstorm XB.
I know for a fact that some of the AFD heads have the bottom of the rocker boss protruding into the intake port. Are yours like that???

Think about it for a minute..

Oil may be able to pass thru and make it's way into the port as you have described. Might be worth pulling the intake rocker studs out and use a sealing agent such as loctite to may sure NO oil can transgress ..

It's worth a shot..
cheers,russ

xdclevo

Read back 2nd post. You allready had that brainstom

__________________
10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

xbgt74

Thanks Guys.....I have used sealant on the rocker studs...which do protrude into the inlet port.Even thought about the crankshaft going into the oil as with the longer stroke and flicking it up into the bores....dropped the oil level down to as low as possible and still blowing heaps of oil out...I think it has to be the low tension oil rings just can't be sealing.So it'll be coming out and i'll be sourcing a higher tension oil ring.(or i'll put the gt with the original motor on ebay)..just out of curiosity xdclevo ...what type of rings has your 408?

russxr67

Low tension oil rings are usually used if you have a vacuum pump. I use Total Seal rings on my engines. CRS1001+.0035

This is with a 3mm oil ring though on Probe slugs. A 3/16 ring will be different.