Opinions for a 440 based race only engine

Well the maiden trip to the track did not turn out well. So, I am looking into options. The current combo is a 440 based 500" with a 4.15 stroke.
I am afraid that it is going into the junk pile. So what I would like to know is a 4.15 or a 4.25 stroke better for a drag engine? I have TF 270 heads, a super Victor and 1050 ultra dominator. The cam is a comp cams solid roller @.050 Int 280* Ehx 284* lift is .672 and .642 with 1.6 roller rockers. The converter is an 8" that flashes to 5500. The rear is a Dana 60 with 4.30 gears. The rear tires are 14 x 32. The car is a 70 Road Runner that is as light as I could make it. With me it weighs 2850.
So What would you recommend for stroke?

Thanks,
Digger73 (Mike)

What is the problem with current engine? If the crank isn't broken then why not use it?

At this point I am not sure what is wrong. The engine died after the first burn out and will not turn over. I haven't gotten very far on the tear down. I just got the engine out and the heads off. The cylinder walls that I can see have vertical marks. The heads look good and the piston tops are still clean. The engine would turn over very slow with the starter but no dice with a breaker bar. So I am expecting the worst case of massive bearing failure.

Digger72 (Mike)

Why are you suspecting bearing failure when you see vertical scoring of the cylinder walls???

Just a hunch. I am thinking that there may have been an oil issue due to the vacuum pump? Like I said I am thinking worst case right now.

Digger73 (Mike)

I've been happy with the 4.15 stroke, I ran it for years with the comp 650 mechanical FT cam to 7000 rpm even 7200 for awhile. And this was with polished, shotpined stock rods.
I do like the lightweight 4.25 crank out there now but it's been a long time since I've looked at rod/stroke ratios.

Pick a pin height your happy to use
Work back to the lightest bobwieght you can with a chev journal rod on either stroke

Aside from the intake, does it have to be a rb block?
In a 400 block a 537 gram Diamond 1.32 piston, one of their custom 130g pins and a 712g k1 6.535 2.1 rod on a 4.25 crank will get you a target bobwieght of around 1870 grams - it would take some exotic components to get a rb down to that, at that stroke

Not enough performance change to go to the 4.25 stroke, unless you can't salvage the 4.15 combo.

I’d get it apart, see what you have to work with....... and go from there.

Keep digging on the autopsy to determine what actually killed the motor? Instinct is oil pressure/bearings problem. Put the crankshaft 'stroke' concerns on the back burner. Your motor configuration sounds fine, get together with Cab (He'll see this and should contact You thru IM) over there in Bend, OR and make a durable motor. This 'racing' stuff is painful some days. Remind Yourself: It's only money.

Thanks for all the kind words and suggestions.
As I stated before I am asking only in anticipation for the worst.
I am a realist in the fact that this is not good no matter what or why.
I am sort of stuck in the RB mode as everything I own is RB based.
I will keep the post mortum going this next weekend. This thing called work keeps getting in the way of my racing.

Digger73 (Mike)

With your combination you're pushing your luck with a stock block. Be it B or RB. With vertical lines I would say something that shouldn't be there is floating around. If you don't have a good oil pan with baffles and good windage tray. That contains the oil around the pickup. I would predict spun bearing.

I have a main girdle and windage tray. the oil pan is a milodon 7 quart with baffles. As for the the pick up, it is a swinging single line external pick up. When warm I had 70 - 80 psi. The vertical lines are not deep just that I can see them. That was my thought also that I have a bearing that has failed. The oil came out as clean as when I poured it into the engine. I even filtered it as it was drained out. Nothing in the filter either.

Digger73 (Mike)

I had the same oil pan and windage tray. With .003 clearance on rods and mains. As I was turning onto return road oil pressure dropped to 10 lbs. The next pass spun two bearings, windowed both sides of the block. I did high tech testing with same pan and windage tray. Strapped oil pan with 7 quarts of water on front of my quad on concrete. Launched it, dang that water was cold! What water didn't come out on launch. Came out when I braked. I fabbed two baffles with BMW style rubber flaps. And welded in covers on both ends of windage tray. Then did the same test, hardly lost any water. It is worth the time and trouble to trap that oil where you need it. Oil drain back is fine too. Have you taken the motor apart yet?

Thanks for the tips.
I have done as much as I could for the oil drain back. I used epoxy to fill in the low places next to the cam. Then I painted the inside of the block. As for the dis assembly, I only got as far as pulling the top end apart then ran out of time. I work 12 hour days so time for the car is limited to the weekends. I will be back out in the shop in a couple of days.

Digger73 (Mike)

What’s our performance goal? Et/mph.

440Source 543 with girdle and ARP 2000 bolts...

Will easily put your car in the 9's on pump gas..

I would like to have the car run low 10's maybe high 9's with the MPH to support the ET.

Digger73 (Mike)

I have a girdle and the ARP 2000 bolts with the combo I have now.
It is running Sunoco purple fuel.

Digger73 (Mike)

I'm betting insufficient ring gap and/or insufficient piston clearance. I'd fix it and run with the 4.15 crank. S/F....Ken M

As i reread this post it sounds to me like your oiling system may be inadequate. What ever you do, set up some form of warning system for oil pressure below 30 psi or HIGHER. With what you have discribed as an engine package, i would think you need a ten quart well baffled pan, and maybe an acusump system with another couple of quarts to stay out of trouble when braking!

I'm trying to understand why he would need all that when I've been running a basic 8 qt. Moroso pan usually with 6 qts. in it and a windage tray street driving the hell outta my car forever and zero issues past 7000 rpms..........

The difference is street driving vs drag racing. G-forces!

Check out Tech talk written by David Reher article #74. He has a lot of really good tech articles. Good read.

Ok, I got the bottom end taken apart. I am thinking that the bearings that were coated with a friction reducing powder coating made the clearances too tight. The black on the Thrust bearing is the remains of the coating.
So, is the crank worth saving? Can the rods be safely ran after they got this hot? Moral of this story is don't listen to someone that is trying to sell powder coating and has no idea about engine clearance.

Digger73 (Mike)

They only sell the coating. The engine builder is responsible for checking and setting engine clearances

I would be more worried about all that blue silicone!

Haul the whole thing down to Grays Automotive in McMinnville and let him set it up for you. Looks to me like you have some good parts but it wasn't set up properly. Now you probably need to have the crank ground and buy new bearings. Might need to hone the cylinders too. Looks like the clearances were too tight everywhere in that engine?

Have Grays assemble the engine for you and then do a dyno test before you put it back in the car. That way you'll know it is good and ready to run.

Sadly, the one I have to blame for this is myself. I assembled the engine.
When it was going together the clearance on the bearings was in spec but on the tight side. I should have stopped and bought new bearings at that time.

Digger73 (Mike)

I know there is alot but that was what I was told to use to seal the block to the main griddle. There was no leak and the Oberg showed no signs of silicone so no harm there.

Digger73 (Mike)

Thank you Andy. I am still sort of new to this area and had no idea what shop to trust.
Do you think the rods are salvageable? They have hot spots from the bearings.

Digger73 (Mike)

You need to get it to a good shop who has experience setting up race engines so they can check everything out. The stuff that got hot needs to be checked for cracks, size and straightness. I can't tell from the pictures what is good and what isn't but I've torn enough of that stuff down over the years to know that it all needs to be carefully cleaned and inspected. Box it all up and take it over to Grays or you could go to King and Larsen down in Wilsonville. Both shops do a lot of race engines.

Load the stuff up and take it to a reputable machine shop. By the pictures, the crank doesn’t really look that bad to me. Most of the stroker cranks I’ve installed have had the bearing clearances way on the tight side. I’m betting that’s what has happened here. Heck, you might just be able to inspect the crank for cracks and excessive wear and if all checks ok, and give it a polish and install new bearings that provide proper clearance and go.

Well I know it has been a long time but I finally got my engine back together. The rods and Crank were redone by the same machinist that Andy F suggested.
I have to give him two thumbs way up to him. He did a first rate job in fact maybe too good! I just got back from Woodburn. They told me not to come back until I am ready to license!
The car is a 1970 Plymouth Road Runner. Please ignore the Reaction times... Thanks to all that made suggestions and gave me input.
BTW this is the first time the car has ever been on the track.

Digger73 (Mike)

That car is honking for a '70 RR. Looks like you're making really good power and the car is hooking up pretty well too. Are you taking the car to Woodburn tomorrow for the Mopar Nats? Paul and I will be there in the swap meet area.

Well I will be there with the car but I was told I can't run it until I am ready to license.
I would love for you and Paul to stop by and take a look at my car.
I will be running my daily driver a 2018 Challenger Scat Pack.
My Challenger is white with blue strips.
Hope to see you there.

Digger73 (Mike)

Take some timing out of it or disconnect the secondaries. Promise you slowed it down and they should let you run.

There are many ways to slow a car down at the track, short shift it by 500 to 800 RPM, over rev it several hundred RPM above the best shift point, let off the off the throttle on the other end or on the starting line 30 to 50 ft. from the starting line. Put weight in it, put more air in the rear tires, deep stage the same every run, lots of options to slow the car down

The next option is that I am going to see if I can start my licensing tomorrow.

Digger73 (Mike)

I'll be glad to watch and sign off on your runs if you can make some of them tomorrow
I'm bringing my B5 1970 Cuda S/P #678C car to try and find a new owner for that rascal

Thanks Cab! That is something I was sort of worried about.
See you there.

Digger73 (Mike)

The car's legal for 9.xxx ETs, but the driver isn't?

The licence proceedure is a breeze.Thet told me 2 half passes.2 in the 10's and 2 in the 9's. First few times in the high 9's they just said to slow it down.
After being licenced I had a great weekend at LVR and after going 147 mph a tech came to me at the end of the day to thank us for coming,,,,then put his hand on my shoulder and said " don'y come back without a parachute"

Yes I built the car to be 9.99 or faster. The lesson to be learned is to never let your license expire.
I had a license when I ran my dragster but when I sold the car I let the license expire.

Digger73 (Mike)

Yes it is! I found out today.
I made my passes and Forest and a friend at the track signed my runs.
As soon as I get the paperwork to NHRA and they send my license time to make the car fast!

Digger73 (Mike)