Question about "high performance" builds, in particular engine longevity. If you have a sleeved aluminum block, all the better to answer my ?

[biomedtechguy]

I'm asking here because I believe the "Resto-Mod" folks are more likely to drive in the ways I intend to vs the Racing Forum.
Although I am having a Bill Mitchell aluminum RB block make the foundation of my 572 stroker engine, I'm going that route to improve my chances of longevity, reliability, and relative ease of maintenence. Trick Flow 270 heads, and I realize that the 4.50 stroke means more piston speed and more "force" when it changes direction vs the 4.35" stroke I had originally planned, I believe that the power achieved from the extra displacement is allowing me to have a CR that won't ever give me problems with detonation on premium pump gas, and the cam specs don't have to be "crazy" either, again resulting in ease of maintenence.
The point of my post is to ask:
Do any of you have stroker motors, and what has been your experience regarding wear and tear on bearings, rings, etc? If you know someone who has this setup, how has it been?
A friend of mine has a BB Chevy and although he's had it built 16 years, he only uses it a quarter mile at a time, but his oil pressure is so low now he DEFINITELY has bearings that need replacement and it has just under 2,000 miles on it. This is a 10 second car (maybe) IF he ever figures out how to get it down the track. I absolutely FREAKED OUT because I may drive 2,000 miles in one year the way I want to use my car, and I definitely don't want to nor should I have to think about it wearing out that fast...RIGHT?

 

[bearman]

Bio, like anything hi performance it must be maintained at every level. So really consider how you will drive your car and then pick the right combo to do it. I seen big motors go a long ways before they tear into it. But also seen folks tear up 20 plus $$$ in a real hurry. Take in all the factors such as oil, coolant package and transmission. The pulley system will be very important and temp control will be everything. Good luck with your build and we're watching.

 

[biomedtechguy]

Thanks @bearman
Much of that is already in place or decided on.
I am transferring my CVF Wraptor serpentine belt and accessories system over, including AC.
I have a Cold Case radiator in use, but I don't know if it is doing the job or not.
I know that may seem ambiguous, but I had changed a lot of "things" all at once out of logical progression and I may just have a Dakota Digital temp sensor glitch. I don't see how the temp can spike off the high end and 30 seconds later be at 180. The Passon 855 is going to back up the 572. I will test its claimed "700 continuous Ft Lbs Torque capacity".
Thanks for the reply.

 

[70ChargerRT]

Thanks @bearman
Much of that is already in place or decided on.
I am transferring my CVF Wraptor serpentine belt and accessories system over, including AC.
I have a Cold Case radiator in use, but I don't know if it is doing the job or not.
I know that may seem ambiguous, but I had changed a lot of "things" all at once out of logical progression and I may just have a Dakota Digital temp sensor glitch. I don't see how the temp can spike off the high end and 30 seconds later be at 180. The Passon 855 is going to back up the 572. I will test its claimed "700 continuous Ft Lbs Torque capacity".
Thanks for the reply.

I think you need to do like bear man says. Build your cars motor for your driving style. I couldn’t imagine having a 572 aluminum stroker for a restomod. That would be absolutely awesome. I don’t know why you couldn’t get it dependable. Use the right parts and shouldn’t have any cap walk. Are you going full roller on the engine? My plans in the future is to do an aftermarket RB block build and for it to be a full roller like my current motor is now and play special attention to lifter bores for any additional work. I’ll probably keep my 240 heads and have them worked over. You may have get a separate gauge and check your temps compared to your Dakotas. My temp gauge on my Dakota just quit working. Im going to switch it over to my Sniper sensor gauge and see if it’s that the problem, hopefully it is. I’m running a AC Delco temp sensor for my sniper as they are known to be more accurate than the sniper and Dakota sensors.

 

[HawkRod]

I only have a 400 block that displaces 500 Cubic inches, AND I don't have many miles on it since I tore it apart to address low(er) oil pressure and some potential piston slap. Note that I bought the engine complete with about 5000 miles on it. Great, top notch parts, but I tore it apart due to the issues mentioned and I am now almost done the rebuild.

With that background, a couple of comments:

With a long stroke, the rods get very long so the pistons must get very short. Your pistons will have the pins encroach into the oil rings like this:

Overall, here are my pistons and rods:

You can see how long the rods are and how short the piston is. With a 4.5" stroke, you will get a lot of side load, and this will be with that short little piston partially out of the bottom of the bore. Bottom line is there is nothing you can do about that short of reducing the stroke.
Interestingly, I am assuming that my Eagle crank had lost about .001" size on the main journals in 5000 miles. I say assuming because my main journals are now almost .001" under minimum spec. Is this due to side loading? I don't know. I believe this was the cause of my low(er) oil pressure.
Best you can do for side loading is pay particular attention to engine specs when building it. Make sure your clearances are spot on. Don't guess, measure every one and I'd say to go for about .003" main clearance. Make sure oil gets to the mains and flows. High volume and high pressure are not necessarily always better. You want the crank to ride on a pressure wave of oil around it. Too little or too much flow is a bad thing. With pressure, more is not necessarily better. Pressure is a good indicator that you are pushing oil through the mains, but too much pressure isn't good either. What you want is excellent oil FLOW to and through the mains. Talk to your engine builder about optimizing that.

On my engine on tear down, you could see that my rings were worn at an angle - almost definitely from short pistons rocking back and forth. A coating to minimize piston to bore clearance would also be helpful to reduce this.

That brings me to comments about the mains in the bock. Make sure they are maybe .0001" - .0003" above minimum spec, but most importantly, with less than .0002" taper. Taper can kill bearings! Be sure your block is blueprinted and that your mains are spot on.

To achieve these measurements, you need a builder that can do this and you need your engine blueprinted. I'd suggest you make sure the builder provide you with specs and values as he goes along. For example, when you block is ready, have the builder provide you all the measurements from your mains. If they are not where they need to be, then fix them.

Good luck!

Hawk

 

[Hemirunner]

The bore length in a 572 is long enough to allow for a 6.76 or 6.80 rod as opposed to the 7.10 rod frequently used. This combo may need some crank work depending on the counterweight diameter, but I prefer the longer piston skirt that it provides for a more stable piston and better ring seal. My old 572 ran for many years in this configuration.

 

[biomedtechguy]

Good info. Keep it coming!! Thanks to all of you!

 

[fbs63]

Put the longest connecting rod in that fits the combo. The longer the rod the less rod angle so less side load. The pistons in new Hemi's and Ls, Lt engines are 1.200 or less compression height and they go 200,000.

 

[Rebelrouser]

I'm asking here because I believe the "Resto-Mod" folks are more likely to drive in the ways I intend to vs the Racing Forum.
Although I am having a Bill Mitchell aluminum RB block make the foundation of my 572 stroker engine, I'm going that route to improve my chances of longevity, reliability, and relative ease of maintenence. Trick Flow 270 heads, and I realize that the 4.50 stroke means more piston speed and more "force" when it changes direction vs the 4.35" stroke I had originally planned, I believe that the power achieved from the extra displacement is allowing me to have a CR that won't ever give me problems with detonation on premium pump gas, and the cam specs don't have to be "crazy" either, again resulting in ease of maintenence.
The point of my post is to ask:
Do any of you have stroker motors, and what has been your experience regarding wear and tear on bearings, rings, etc? If you know someone who has this setup, how has it been?
A friend of mine has a BB Chevy and although he's had it built 16 years, he only uses it a quarter mile at a time, but his oil pressure is so low now he DEFINITELY has bearings that need replacement and it has just under 2,000 miles on it. This is a 10 second car (maybe) IF he ever figures out how to get it down the track. I absolutely FREAKED OUT because I may drive 2,000 miles in one year the way I want to use my car, and I definitely don't want to nor should I have to think about it wearing out that fast...RIGHT?

Never ran an aluminum block on the street but did run one on the track. ON the oil pressure, first the Mitchel block has what is called priority oiling, the oil goes to the mains and rods first, then lifter galleries second, so they do not require near the oil pressure as a stock Chrysler block. When the engine is hot at idle the oil pressure will drop, as long as it snaps back when you touch the throttle all is good. After a hard run on a hot day my oil pressure would drop to 30 lbs at idle from 80 lbs cold. I had 600 runs on the engine and bearings looked like new when I pulled it down to check it out. Aluminum expands when it gets hot clearances will grow.

Short rod long stroke will load pistons and cylinders harder than a better rod stroke ratio. A 540 with a long rod would be a better choice in my opinion for street duty, and I doubt you would miss the HP. I used an Ohio Crankshaft kit 7.1 length rod 4.5 bore 4.25 stroke the rod stroke ratio is almost as good as a stock 440. 540 is 1.67 ratio stock 440 is 1.8
The heads you are using are good, but I don't think they will feed the extra inches, you will get more torque down low with the 572 but I would bet the HP is about the same.

Other issue with the aluminum block, from the heat expansion the sleeves will distort, and you will lose ring seal over time, again I don't think there is a way around that, so it is not going to be a 1000,000 mile engine. At least on my engine when if started losing a little power it was a ring seal issue every time. Driving easy on the street it may not be an issue don't know.

 

[biomedtechguy]

I'm not certain, but I believe a 7.1" rod was specced by my builder. I definitely have a 4.50 bore and stroke. I'm leaving the details to my builder, but I have been emphatic about what I'm looking for, and I was insistent about EDM roller lifters and employing Michael Beachel's (B3E) valvetrain geometry correction kit and the T&D rockers he uses for my application.