So, on a 472, are chp-VT61 rockers good ?

So, my old buddy LeeRoy was a machinist in the Navy, and now he does high performance engine machining on race cars. He says the cast iron caps on a cast iron block are sweet because all the iron expands at the same rate as the block heats up. He says Steel main caps can be a bitch because they expand at a different rate... If I have a guy copy a set of 472 main caps in 300M alloy, then heat treat, and then cryo-treat, I would have a fancy set of main caps to go with my ARP main studs on my new 472. Anyone know if the rate of expansion on 300M steel is close to the rate of thermal expansion on Caddy 5200 iron blocks?

Regards,
Roy who dances with 472

If he can do main caps from scratch, what about a complete block girdle similar to the 6.0 Powerstroke diesel block?
 
My bad bro D,
I didn’t even think about that. I guess my thoughts were focused on my specific application. I suppose there are quite a few others that could benifit from billet mains if they are in fact a solid solution.

I don’t know what the benifits of various metal billets are, just something that would resist cap flex better than the stock caps would be nice.
A strong billet cap would not be a good idea in my opinion. No flex=broken blocks.
Just sayin'.
 
If he can do main caps from scratch, what about a complete block girdle similar to the 6.0 Powerstroke diesel block?
And why doesn't he know or be able to get these temp. specs. A Navy machinist should have these things punch pressed into his head. I knew a Navy welder that could weld gum wrappers. Never forgot anything he learned in the service concerning his job.
 
A strong billet cap would not be a good idea in my opinion. No flex=broken blocks.
Just sayin'.

How do you figure? That’s an honest question. Haven’t guys at higher power levels been using straps and studs to reduce/eliminate flex in the caps for a while now? I’m not shooting for the same goals as cadman above, so I’d honestly like to know at what power level in your option the billet cap would become a danger to the block.

A lot of high power cads seem to burn up bearings badly on the mains due to flex in the caps. The crankshaft can get wasted pretty quickly this way.

If what you say is true...well considering how long it took me to get a crankshaft I’d be screwed either way and most likely purchasing a new long block regardless of what happens (crank vs block).
 
How do you figure? That’s an honest question. Haven’t guys at higher power levels been using straps and studs to reduce/eliminate flex in the caps for a while now? I’m not shooting for the same goals as cadman above, so I’d honestly like to know at what power level in your option the billet cap would become a danger to the block.

A lot of high power cads seem to burn up bearings badly on the mains due to flex in the caps. The crankshaft can get wasted pretty quickly this way.

If what you say is true...well considering how long it took me to get a crankshaft I’d be screwed either way and most likely purchasing a new long block regardless of what happens (crank vs block).
Just thinnin'. If the caps don't flex anymore something has to. I'm not a machinist or a metallurgist, But something has to flex. It's my Kraut heritage that starts asking questions. Over science crap.
 
1FB4AAF5-131D-4EEA-9B6E-DF7643CB759D.webp


Gentlemen:

300M is used in landing gear, and high-end u-Joints on the rubicon trail. In many ways, it is as strong or stronger than the best ARP Main Studs you can buy... The 472 J-20 used to break u-joints and then after I switched the joints out for 300M U-Joints, the U-Joints were no longer the Weakest link, and I started breaking a succession of Detroit Lockers and Ring Gears...

Not trying to start a total shit-storm here... Just thinking about Caddy Big Blocks and the best material for LeeRoy to use on new MainCaps for my 472...

Thanks for the ideas,
Roy
 
If he can do main caps from scratch, what about a complete block girdle similar to the 6.0 Powerstroke diesel block?


That is a great idea ! When I see LeeRoy on Saturday, I will ask him if we can go 6.0 PowerStroke style...

Here is one more thing from Bro. LeeRoy that makes me run thought experiments... We were looking at a 540 BBChevy that had scored the crank, and LeeRoy said feet per second of bearing speed can be a huge problem... The size of the bearing journal means you get X amount of bearing travel per crank rotation. The larger the journal size, the higher the feet per second at say 6,400 RPM, and at the manic number, even coated Clevite-77 bearings give up the Ghost. So, if you wanna make big power, and not spin it over 6,000 RPM, why not just go Turbo, boost it big, and save the bearings by not twisting the crank to the moon?
 
48austin: I understand what your saying as at a certain point something always has to give, I was just curious if you had ever experienced such a failure. Im shooting for a “modest” 750hp in boost at 5500 or so, and just trying to do anything possible to keep her alive.

Roy H.: no shit storm started IMO, I believe me and 48austin are having a nice discussion on the topic at hand. He is correct that at certain thresholds all mechanisms have a weak link, I am simply curious as to what the thresholds of the options available to my setup that may also reveal something potentially useful to others in a similar boat as me (limited pan clearance, extreme setbacks ect)
 
OK.

Here is the boat we all have to float within.

Go find a nice used Caddy Main Bearing in your garage. Next walk over to your Anvil, Bench Vice or Work bench.

Now, take a deep breath.

Next, grab your best Ball Peen hammer, and place your bearing insert on the best solid surface you have.

Now, take a very deep breath, and strike the center of the bearing as hard as you can while you say Detonation!

Repeat this 100 times, and then take a close look at your Super Crank Scraper bearing... LeeRoy says detonation from lack of computer controlled fuel injection just pounds the crap out of bearings. The main bearings close in at the ends, and scrape all the oil off the crank. Then, POW!!!!

The bearing shells and the bearings are way so softer that hi nickel cast iron, and when pounded, they Taco and scrape oil with bad consequences....

Thoughts?
 
Last edited:
48austin: I understand what your saying as at a certain point something always has to give, I was just curious if you had ever experienced such a failure. Im shooting for a “modest” 750hp in boost at 5500 or so, and just trying to do anything possible to keep her alive.

Roy H.: no shit storm started IMO, I believe me and 48austin are having a nice discussion on the topic at hand. He is correct that at certain thresholds all mechanisms have a weak link, I am simply curious as to what the thresholds of the options available to my setup that may also reveal something potentially useful to others in a similar boat as me (limited pan clearance, extreme setbacks ect)
Only once. And it may have been created from making to much power and tooooo much gear. Or old metal. 194 Poncho punched 120, ram air IV Head, forgot intake name, 950, Nash 5 speed, 6:14 gear, 30x10.5 M&H. Made a few passes. And then the crank broke in half 3/4 track. Was a mess. Things were not good. Blew the trans flywheel scatter shield out of the car. Cut the brake line at the master. Still used the single master on that little tempest. OOH but it came out of the hole REAL nice.
 
OK.

Here is the boat we all have to float within.

Go find a nice used Caddy Main Bearing in your garage. Next walk over to your Anvil, Bench Vice or Work bench.

Now, take a deep breath.

Next, grab your best Ball Peen hammer, and place your bearing insert on the best solid surface you have.

Now, take a very deep breath, and strike the center of the bearing as hard as you can while you say Detonation!

Repeat this 100 times, and then take a close look at your Super Crank Scraper bearing... LeeRoy says detonation from lack of computer controlled fuel injection just pounds the crap out of bearings. The main bearings close in at the ends, and scrape all the oil off the crank. Then, POW!!!!

The bearing shells and the bearings are way so softer that hi nickel cast iron, and when pounded, they Taco and scrape oil with bad consequences....

Thoughts?
Detonation? Why?
 
Sorry. I did not give the back story, so I apologize. Before I ran the 66 Lemans, I had a 64 Tempest with a 421 and ArmaSteel crank. It was silly fast. Now that I know my 472 crank is also the GM ArmaSteel style crankshaft, I just wonder how much power can be made... I will now switch to de-caf and try to stay out of the way.

Thanks again and keep the faith,
Bro. R
 
Only once. And it may have been created from making to much power and tooooo much gear. Or old metal. 194 Poncho punched 120, ram air IV Head, forgot intake name, 950, Nash 5 speed, 6:14 gear, 30x10.5 M&H. Made a few passes. And then the crank broke in half 3/4 track. Was a mess. Things were not good. Blew the trans flywheel scatter shield out of the car. Cut the brake line at the master. Still used the single master on that little tempest. OOH but it came out of the hole REAL nice.
Sorry. I did not give the back story, so I apologize. Before I ran the 66 Lemans, I had a 64 Tempest with a 421 and ArmaSteel crank. It was silly fast. Now that I know my 472 crank is also the GM ArmaSteel style crankshaft, I just wonder how much power can be made... I will now switch to de-caf and try to stay out of the way.

Thanks again and keep the faith,
Bro. R
Huh?
 
Detonation? Why?


Detonation is abnormal combustion and LeeRoy says it is the real killer. If you have a carb and jets and that old school stuff, it is real easy to get too lean, have too much spark advantage or advance, and go into Detonation. The force goes down the rod, and hammers the thin little bearings. I say when you run a turbo setup and fuel injection, you can tune it all to the edge, and yet stay out of Detonation.

This saves the bearings, make peak torturous torque at a lower RPM, reduces Detonation, saves head gaskets, keeps the main caps from getting all shiny and walking all over the place.

Bottom line- Cad Man May be correct with Turbo Power and Fuel Injection...
 
48austin: I understand what your saying as at a certain point something always has to give, I was just curious if you had ever experienced such a failure. Im shooting for a “modest” 750hp in boost at 5500 or so, and just trying to do anything possible to keep her alive.

I would still go with Cadman and Cadco on recommendations. Cadco has been in business for many years. You don't stay in business this long by giving wrong info. And Cadman has the "screwed up" numbers in his brain to come up with any profile you might need.
 
The reason I wouldn’t be able to run traditional cap straps and long studs is due to running a 425 transmission I have to measure clearance to the “hump” in the trans pan to figure out what I have to work with.

As for power cadman has already given me some insight on the cam to go with , and I already have my turbo maths worked up for proper sizing ect. Power wouldn’t necessarily be my issue...keeping the bottom end alive is. The power numbers posted above are to just a guideline as to what the bottom end would have to live through. I already have a fairly solid plan, however I worry about cap walk as it has plagued others in the past.

Roy: i am well aware of detonation....as that was what destroyed my first turbo car (didn’t understand AFR yet and turned the wick up) I have no need to hammer bearings on a vice lol my current engine when I bought it was sufficiently hammered. Yes detonation is a danger, but is manageable and no mysteries to stopping it. Even when running blowthrough carb
 
A machinist handbook has coefficient of expansion tables for all metals .

I dont see that being a problem. If it were aluminum yes but it ain't..

I would stay away from tri metal mains


Bi Metal .. 4906MA

A series

Sealed Power® A-Series® aluminum-silicon bi-metal alloy engine bearings deliver greater seizure resistance than tri-metal materials, dramatically reducing or eliminating bearing wear in a wide range of automotive and truck engines. A-Series bearings are manufactured with silicon, which provides greater surface hardness for increased wear resistance. In addition, the silicon particles help polish the crank surfaces and bearing journals during engine operation, further reducing friction and related wear. ©2008 Federal-Mogul Corporation. Sealed Power, A-Series and Contoured Flange are registered trademarks of Federal-Mogul Corporation. All rights reserved. Engine Bearings sealed power ® A-Series ® Bored Micro-Groove Design A-Series bored, “micro-groove” design provide hundreds of oil-filled channels that flush away debris, improves oil retention, and increases fatigue strength

From Cadco's catalog

Cad Company recommends the standard Clevite rod and main bearings for almost all applications for which they are available, and coated standard Clevite rod and main bearings for most other applciations. While there are other breands of bearings out there (and we do carry them), the bottom line is that the standard Clevite bearing is still the best choice in most cases.


I think they are saying this mainly due to typical careless reckless assembly habits

Sealed power has changed the makeup of the bearings. Much improved
You just cant leave dirt in the parts

I would consider getting coated bearings Cant hurt and may help
 
Last edited:
Back
Top