Any input on what shaft mounted rockers to use?

[Caprimaniac]

Well.

The racing season is now over and it ended somehow not good.

The valvetrain have been behaving very nice, and engine power was very good.

Last weekend rod bearing on cylinder 2 failed, and the reason might be known....

First one question: The rod bearing on cylinder 2 was completely gone, the rod cap was blackened and the rod bore is not round anymore. How long does it take to make such a damage? Two minutes or 10 minutes of high RPM driving?

Needless to say I need a rod replaced and a crank reground/ checked.

But now to what caused this. There was a modified dual sump on this engine. I HAD BEEN ANXIOUS ALL YEAR because the oil pressure reading was going down low in the tight ends of LH and especially RH corners at the track. As it was returning to 4 bar in a straight, I didn't take much notice of it. At this very last run, I noticed low pressure for a longer time; at both the start, the ight & the end of bends. After 10 laps it started to make alot of noice....

It was not the bad rod I hear knocking, but the rods hitting the windage tray (customized & welded to the bottom og the oil sump).



As I did have the dip stick in the front sump, and the oil level at "max" was at just below rod/ crank - which means about level with the upper floor of the pan, this is the explanation I'd bet for: Oil level in front sump OK, but much too low at the rear- caused by the oil getting trapped in the front, not showing actual oil level. Another piece of the cause might be one of the trap doors had broke loose. (At the bottom of the picture.)

Here's a nice painting:



What I should have done: Made a connection between front and rear sump... Thought of it, but never happened.

Now I'm installing a Canton roadrace pan.

Oh well; the engine lasted 3 years and with 8000 rpm redline & an amature builder, what more can you expect?

RS

[RICK LAKE]

Caprimanic Your theory question numbers are wrong. .068" is the clearance TOTAL for spring coil bind. This tightness may cause the coils to hit each other on full open. IMO and possibly wrong, I want to match the whole valvetrain to an rpm range. I want a low seat pressure but a spring rate in the 4-500 pound reading for a solid roller to turn 7,500 -8,000 rpms and hold float control. I don't want 400 pounds banging the valve into the valve seat, close it without hammering Camshaft profile has alot to do also with this control issue.
Oiling of motor, Since you have the track bug, going dry sump would be alot better way to go. If the cost is too high then add an accusump (3 quart) to the oiling system to help control oiling pressure on high "g" turns. This way you will always have 30-40 psi going to the motor. The only problem again with this is, the oiling pressure at the gauge IS NOT what you are getting at the other end of the motor. THere are oiling modes like a supply line from the main galley to the back of the block and tie into the lifter galley to help oil the front or back of a motor. 1.5 extra quarts of oil helps. The canton pan is better than nothing but you will still get the same problem you have now. I have a Canton on my FE motor and have had no low oil pressure going around long turns, reason for accusump. Have to make sure you reload the tank before turning off motor. On cool down lap make sure to fill and turn off. Sticker on dash help to remind you. I would also grind smooth the inside of the block or any oil returns to the pan to help get the oil back to oil pan and pickup. I don't beleive in painting inside of motor, tryed it with Gyptal and flakes over time, clogged up and almost killed motor from oil problem.
#2 rod bearing, last to get oil? question answered, if first to get oil bearing clearance too large, metal to metal rubbing. Should hear rod knock about this time. Good luck Rick

[Jac Mac]

Bite the bullet & go dry sump, I have seen videos of some tracks in your area & they are fairly 'busy', lots of rise & fall, long sweepers & not a lot of camber... An accusump might not get time to refill/recharge in between points where the wet sump is picking up air & that can lead to the accusump being recharged with an aeriated oil mix & since the time frame is short, that is what gets fed straight back to your motor...

Dry Sump, .... looks like you have a world products block, has that got priority oiling?, if so when you fit up the dry sump, split the outlet from your remote filter & plumb it into both front & rear fittings...... Oh and check your crank for a bend, not often you get away with that much heat without tweaking the crank, especially since you kept on driving with the bearing toasted.