cyl pressure quench piston and oiling questions

[lyonsy]

ok a couple of quick questions
what do you all think are safe cyl pressures to run on the 1v/2v heads
and canted valve designs like the xflow and clevland which are det and knock prone.
is quench affected by having the pistons poping out of the bore by 5thou or so
will this rising out of the bore by 5thou or so affect the pistons rings or sealing of the combustion chamber?
when ive been running the xflow ivebeen having drama's keeping the bearings up to it
the oil i use is penzoil penzane 5w/50
ive been told that the clevland v8's ave simerlar drama and when installing a soild cam they fit some plugs to restrict oil flow to the cam so the mains and bigends recieve more oil.
i was told they have a camshaft piroty oiling system?
thanks again
mark

 

[Lazy JW]

The pistons in my 81 300 come about .005" out of the block with no problems whatsoever. This is a mild, daily driven street engine built for reliability and low-speed torque, quite the opposite of your application.

As for the oiling problem, doesn't the oil just naturally flow to the head in the land down under? j/k Sorry, couldn't help myself. I have no legitimate answer for that problem.
Joe

 

[addo]

I know the roller rocker setups used to pump excess oil to the head. Some guys would restrict the flow a little with pipe cleaners fed inside the pushrods.

If you weren't running rollers on a 2V head, then unless there was a major bleed-off for the oil, you should have plenty of pressure for the mains and big ends.

 

[rmt]

My father smoked a pipe. I grew up with pipe cleaners always around, using them for a multitude of uses and to this day I always have a pack in one of the drawers of my tool box. My arsenal is not complete without them.

I now have yet another use for them, and a clever one. Even if I never use the idea, I'm ready.

 

[StrangeRanger]

There's a hotrodders' trick with the Cleveland of running an external oil line from the galley just above the filter back to the galley at the rear main, supplying oil to the main galley from both ends and sort of duplicating the oiling pattern of the old FE Side-oiler 427. That way good flow and pressure is guaranteed for the entire crank ass'y without restricting flow to the top end. I have no idea if this is applicable to the X-flow 6 or not.

Addo or Deano will be heard from shortly.

 

[xctasy]

Yep (. .)

Lee Morse was part of the Martel reworks of the Lima big block in 1968, the 1969 Boss and the 1970 Cleveland and 351M/400 Ford. Priority oiling systems were changed to give the lifters the oil first, then to the mains.

In hard run race engines, the problem then became too much oil from the oil through pushrods, effectively drowning the rocker covers at 7000 rpm onwards, often runnig bearings. TransAm guys with the 302 Boss and NASCAR guys with the 429 Shot Gun used external drains, then, finally external oiling systems like the side oiler 427's.

Problem then was very short life of valve springs. Lee Morse did some tests, the spring life unstrangled was way higher than the strangled supply. If you repace the springs often, or have a way of testing them insitu against the seat and fully open pressure specs, you can restrict oil and gain full supply to the main bearings.

The second reason for reworking the oil system by lifter restriction was that the 351c had cavitation in the oil pump at 7200 rpm. Since the 351C was Fords all out NASCAR and drag race engine for many years, that was a major problem. By restricting oil supply to the lifters, this reduced caviation untill 8500 rpm, and added supply to the main bearings, whic were always over worked becasue of there huge size, and the vibration of the canted valve heads.

On an X-flow six, restriction of the priority lifter delivery supplys more oil to the main bearings, and will help your engine live longer. According to an ex SVE engineer, the 250 I6 is safe to 7500 RPM if you can get it rev that far.

 

[lyonsy]

thanks for that deno much much much appreicated i havent grabed a bearing yet but its been close and there ant much bearing material left.
i can also attest to the fact a 250 will live to 7500 and beyond 7800 is the highest ive maxed out on.
that is on slow rolling starts where ill use 2nd gear to get a jump some time you caught up and cant shift till the back straght by which time iam hitting 7500/7800 with a flat shift peaking rpm's to over 8.
it dont happen often about twice a season.
when the my father raced he had a restricted class stock engine iron head 250 stromberg and spun that out to 7500 every race untill he could get the gearing he wanted.
its not getting them to rev hard just to make power there 200's are being spun to 8000+ in speedway use but the 250 just seems to max power out at around 6500 with a max ported head.