Raced the barn find Merlyn at Blackhawk

[Velodrome Racer]

I raced this past weekend at Blackhawk Farms with VSCDA in my first open wheel event and the first time the 1972 Merlyn 20A has seen a track in 23 years. What a blast! Stayed safe-ran well-got faster each session. Final race-started 18th of 30 and finished 12th, which was 5th in class. A few questions that I was seeking answers all weekend.

What is expected of low oil pressure when you are idling as you come off track? I saw 5-10 psi, but at race revs-had 50-60psi and could rev it and get 10-15 while coming off track. I am running an oil cooler and Valvoline SR1 20/50 wt I am going to replace the gauge and the SS line that serves it just in case too.

What oil weight? Some say 20/50 and others say 30 wt or 10/30?

We pulled the pan drain plug, saw no metal at all-the 1/2 qt of oil we checked had no metal in it at all-I am going to pull and cut the oil filter to check as well.

Is there a secret in replacing the scavenge oil line from the pan to the Pace pump? I should-but that thing is next to impossible to change-the Pegasus one is stiff-I get it, but how do you get it to fit both the pan fitting and the oil pump fitting?

What is the secret to keep the valve cover from leaking too?

Anything else I should do to make sure I am ok to race and have no engine damage?

Help..I want to race at Indy in August-but not if I have an engine issue.

[Peter Olivola]

I seem to recall issues with oil pressure relief valves. If you've got good pressure at operating revs but low hot idle pressure I'd start there.

[2fast2stop]

Make sure the valve cover is vented............

[Velodrome Racer]

I seem to recall issues with oil pressure relief valves. If you've got good pressure at operating revs but low hot idle pressure I'd start there.

Thanks-That is a great idea. I assume I can replace the spring/ball/plunger (Like i have on my Sprite racer) with what Pegasus sells or is the Pace so different? It seems they sell Titan parts and not Pace.
We did get 20 psi at idle after the car sat for a couple of hours and I had turned in the adjuster screw one full turn.

[Garey Guzman]

I've been using 20-50 VR1 for many years now. I have found my idling oil pressure at the end of a hot race to drop into the 10-15 psi range and I have not had an oil-related failure. This weight has been the suggestion of my engine builders based on my desire for maximum durability. I'm not planning on doing the Runoffs so I'll gladly sacrifice that last couple % for more weekends between rebuilds. As long as it pops up past 30 psi when I rev, I'm confortable.

I had an engine drop to 10-15 psi during a race, in fact, the last half of the race. It didn't blow up but I pulled the motor after finishing the race in 2nd. I don't know how many hours that engine had but it was likely a lot.

All that said, I would plan on an engine rebuild at some point soon for an engine I didn't know anything about prior to purchase!

[TimH]

My understanding is that VR1 (the racing stuff) has plenty of lead for our flat tappets.

That sort of behavior hot/cold pressures has been seen by many of us without a problem being found. A few have gone to thinner weights to minimally increase horsepower and have indeed paid a price.

[Allan31]

My understanding is that VR1 (the racing stuff) has plenty of lead for our flat tappets.

That sort of behavior hot/cold pressures has been seen by many of us without a problem being found. A few have gone to thinner weights to minimally increase horsepower and have indeed paid a price.

You're racing in Historic class with steel wheels and low technology. This is about the most fun you can have with your pants on.....Congratulations on your barn find, I'm sure there will many more fun weekends ahead for you !!

[problemchild]

This may be an over-simplified answer, but don't idle it when its hot off the track. Keep enough throttle to keep oil pressure, then shut it down as quickly as possible. Follow your engine builder's recommendations for oil. You can likely boost hot oil pressure at idle by using heavier oil or overcooling it, but you will just reduce ontrack performance.

Nice car!

[Westroc]

It's pretty common to have that pressure after a race. Actually that's a heavier oil than I would prefer personally but then I've always been a Redline guy. The "problem" I have w/heavy oils is it takes way too long to get to the wrist pins. An area most guys don't even think about. A good suggestion is: We always wired up a oil warning light for low pressure. Set it no lower than say 10-15lbs and it should flicker in pit lane off and no where else! Gives you a warm fuzzy.

[EricP]

First off, that is a really cool car. Classic FF.

Next, is there anything for support directly behind the middle/base of your head? It LOOKS like your head “rest” is high and in a rearward impact your shoulders and neck/lower head could sort thrust under the head rest. Again, it could just be optics and I’m no engineer but God forbid I’m right, you might want to check into that. Or hopefully someone else here can say it is a non-concern...