Glen,
The oil holes in the tappets are mostly to reduce the additional mass
from the oil in them. There shouldn't be any consequence as far as
oil drainage from the head. When filling the engine with oil the
first time, it took a VERY long time for the oil to reach the sump.
That is why I suspect the pushrod clearances in the block. The head
was opened up to accommodate them, but the block was not because Mike
made this decision after the bottom end was already built. In
addition, the pushrod holes in a sock setup are already smaller than
the ones in the head. Mike's pushrod diameter is .310 dia. and the
stock opening in the block is .397+ or -. That only leaves a space of
around .044 around the circumference. (about the space of a wide gap
spark plug. Is this enough clearance??? I'm not sure, but it seem
like very little to me. Vizard's book has a passage stating holes in
the block may need to be enlarged when using larger diameter
pushrods. Seems the easiest test solution is for Mike to change to
stock pushrods and see if the problem goes away. We didn't have a
chance to vent the aluminum valve cover so I'm thinking this might
exacerbate the problem once oil starts to accumulate in the valve
cover.
Gerard
At 10:21 AM -0700 9/3/04, Glen Byrns wrote:
>Mike,
>
>I'm running the 1.5 rollers with the stock pushrods and had no oil pooling
>problems. Then again, the flow of oil out of the rocker gear is not that
>great, amounting to a seep rather than a gush. I'm a bit concerned about
>the amount of oil that must be coming out of yours to fill up a rocker
>cover. Did you also change over to the chilled iron tappets that don't have
>the oil hole? Not that those eight little holes will make that much of a
>difference, but something isn't right. Have you watched the rocker gear
>with the cover off while the engine is running? (messy, but sometimes
>necessary)
>
>Glen
>
>
>> Bob,
>> I'm not sure even slender pushrods are going to help that much. I
>> talked to Gerard over the phone last night and we compared clearances in
>> a standard 1275 block he has at his house and the tubular pushrod
>> diameter. The hole in the block is only about 1/16 larger than the
>> tubular pushrod. Would this clearance slow 20W-50 Penrite Running In
>> Oil drainage back into the block? Gerard also mentioned that I am
>> probably building up pressure in the valve cover (not vented) because
>> the oil is not draining back into the motor, forcing oil to go the only
>> place it can, down the intake valve stem on the intake stroke. This is
>> why the blue smoke gets worse the longer the car is running. I can vent
>> the valve cover, but it does not solve the problem of the slow draining
>> oil and I will probably still get the blue smoke maybe just a little
>> less. The Tubular pushrod is 5/16ths diameter and the standard stock
>> solid 1275 pushrod is 1/4 inch diameter. Will 1/8th inch clearance
>> drain THAT much better than 1/16th? That does not sound like it is
>> enough to me, but this is what the stock pushrod runs in a stock block.
>> Maybe as oil pressure drops during run-in coupled with the pressure
>> relief of the valve cover it might get better, but why does the oil take
>> so long to drain when it is filled up after an oil change? I think
>> after all is said and done I will probably have to abandon the 1.5
>> rockers and the Isky Tubular Chrome Moly pushrods and go with a stock
>> 1.3 setup, not getting the full use of the 266 cam and ported head. Oil
>> pressure is pretty high in this new motor, but limiting the oil to the
>> rockers still does not address the drainage problem.
>> Mike MacLean
>> 60 Sprite
> > 56 BN2
--
One meets his destiny often in the road he takes to avoid it.
~French Proverb
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