Four bolt mains

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SWED67barracuda

SWED67barracuda

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Hi . Have anyone with any success used these milodon main caps . I think i asked once before what the pro`s thought about them and the general idea was that one should get a race block if that kind of power is to come out of it, or cut off the outer parts of them and use them as two bolt caps and I`m fine with that. But it really did not answer the above question . Have they been used with any success.Best regards Ubbe
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SWED67barracuda said:
Hi . Have anyone with any success used these milodon main caps . I think i asked once before what the pro`s thought about them and the general idea was that one should get a race block if that kind of power is to come out of it, or cut off the outer parts of them and use them as two bolt caps and I`m fine with that. But it really did not answer the above question . Have they been used with any success.Best regards UbbeView attachment 1715449443
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I have a 1967 340 block I got from a friend of mine that has them installed. I am not crazy about the angled bolts, and where they go into the block. Not a lot of surface for the bolts, and can only drill and tap a minimum depth. I didn't see it necessary for this application, but they are on now. Unless you are missing some main caps, I don't think I would do it. I think the better option is the Mopar Performance caps that Rocket has for sale . I am reassembling the engine now. It has a set of W-2 heads on that leaked, so it had very little run time and never raced. So the main and rod bearings looked fine. But I can't testify if it will last yet.
 
Sterling said:
I have a 1967 340 block I got from a friend of mine that has them installed. I am not crazy about the angled bolts, and where they go into the block. Not a lot of surface for the bolts, and can only drill and tap a minimum depth. I didn't see it necessary for this application, but they are on now. Unless you are missing some main caps, I don't think I would do it. I think the better option is the Mopar Performance caps that Rocket has for sale . I am reassembling the engine now. It has a set of W-2 heads on that leaked, so it had very little run time and never raced. So the main and rod bearings looked fine. But I can't testify if it will last yet.
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Ok thanks for input . I also think there is very little material for the outer bolts , and how much stronger can it make the bottom . Might be a little risky perhaps even if one has a good machinist to do the job. I also have a 67 block and a 71 one . Any how , you got them installed and it works . Good to hear .
 
What is "that kind of power"? People have made 600 plus HP with Chrysler's stock two bolt block. At what point to you go to big block?
 
RustyRatRod said:
What is "that kind of power"? People have made 600 plus HP with Chrysler's stock two bolt block. At what point to you go to big block?
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As I said . Everyone says two bolt caps is enough . I just asked if anybody uses them and what is their experience is with them .
 
SWED67barracuda said:
As I said . Everyone says two bolt caps is enough . I just asked if anybody uses them and what is their experience is with them .
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I think two bolt mains are plenty sufficient. I do know that the block has to be made a certain way regarding the main webbing. Not all of them are created equal in that area. If the block you have does not have the "extra meat" in the main web area, installing 4 bolt caps is pretty much a moot point.

I would just let the Chevy guys keep thinkin it's a good thing. LOL
 
RustyRatRod said:
I think two bolt mains are plenty sufficient. I do know that the block has to be made a certain way regarding the main webbing. Not all of them are created equal in that area. If the block you have does not have the "extra meat" in the main web area, installing 4 bolt caps is pretty much a moot point.

I would just let the Chevy guys keep thinkin it's a good thing. LOL
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I think Chevys might really need them . Machinists I´ve talked to says mopar blocks take more effort to machine . mopars are harder . And L Shepard says mopar blocks are made from the good stuff in comparison to others . I am aiming for 500+Hp. So I´m Ok . Just like to hear folks input on those Milodon ones.
 
There is a reason why the outer bolts are 3/8 on those caps (and they are offset) and on the T/A, X and R blocks the caps have 1/2 inch in line bolts that aren't splayed.

When you stick that bolt out there like that, you better have the main caps on and torqued when you hone the block or it will pull the bottom of the bores out of round (caps should be on an torqued anyway, but I've seen many guys that leave them off).

There isn't much materiel out there. Any hole you put there will eventually fracture. Always.

If you keep the RPM's down, and keep it out of detonation it will probably live. But...the block is inherently weak right there, and the threads and hole there are just as likely to form a fracture as not.

That cap with studs and cutting off the outboard bolts would be better than using the outboard bolts.
 
SWED67barracuda said:
I think Chevys might really need them . Machinists I´ve talked to says mopar blocks take more effort to machine . mopars are harder . And L Shepard says mopar blocks are made from the good stuff in comparison to others . I am aiming for 500+Hp. So I´m Ok . Just like to hear folks input on those Milodon ones.
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I agree. Although there are a FEW Chevy casting numbers that are considered high nickle content, most all the Mopar stuff was.
 
The general consensus from the guys I've talked to over the years is that they weaken the block and are more of a determent than help. The web where the outer bolts go is pretty thin there anyway.
 
Ok , it´s to risky a business to use these as they are. Better to cut outboard parts off and use a girdle with studs . Thank´s for input.
 
pittsburghracer said:
So does a stock Mopar windage tray keep oil in or oil out of the crank area.
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Both unless you modify it.
You know the answer.
The oil level is so close to the crank, it keeps it from getting whipped up into it.
I Swiss cheesed one with a million holes, to help with the oil that gets trapped.
A crank scraper is probably a better option, along with a properly baffled pan, as that’s what I put on the last 340 I built for a customer. Made by Kevco.
 
I’m going to bet it’s been 12-15 years since I stopped using them. I’m kinda happy with a milidon oil pan but wish we had some other fancier options like the Chevy guys. I bought a Canton pan after using one on a friends chevy I build but it’s a piece of scrap.
 
12swinger said:
Both unless you modify it.
You know the answer.
The oil level is so close to the crank, it keeps it from getting whipped up into it.
I Swiss cheesed one with a million holes, to help with the oil that gets trapped.
A crank scraper is probably a better option, along with a properly baffled pan, as that’s what I put on the last 340 I built for a customer. Made by Kevco.
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I have also been thinking about this with oil splash in the rear cylinders . when i downshift from fourth to third and give wot, i get detonation from what i believe is excessive oil . So you say oil also gets trapped on the "wrong" side of the W.tray. Hmm...of course. I have been looking for scrapers , not found any . I have just dropped the pan to baffle it , guess there is more to look at .
 
I've been running two bolt main blocks as long as I've been running small block Mopars. My engines have ranged from a basic stock motor to the 416 stroker motor I'm running now. My 416 dynoed 623 hp, 511 lb/ft torque @ 6400 RPM. I've had no problems, other than one thin cylinder wall due to .060 over bore & that was due to not having the block sonic tested. But being as my current set up is race only, I did a full fill of HardBlok just for stabilization.










m
 
Demonracer said:
I've been running two bolt main blocks as long as I've been running small block Mopars. My engines have ranged from a basic stock motor to the 416 stroker motor I'm running now. My 416 dynoed 623 hp, 511 lb/ft torque @ 6400 RPM. I've had no problems, other than one thin cylinder wall due to .060 over bore & that was due to not having the block sonic tested. But being as my current set up is race only, I did a full fill of HardBlok just for stabilization.










m
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Did you fill the block since its .60 over?

Jake
 
Jake,

Yep, it a full fill up to the bottom of the water pump holes of the block. So all I'm actually cooling is the top of the block & through the cooling passages of the heads.

Bill S.
 
SWED67barracuda said:
I have also been thinking about this with oil splash in the rear cylinders . when i downshift from fourth to third and give wot, i get detonation from what i believe is excessive oil . So you say oil also gets trapped on the "wrong" side of the W.tray. Hmm...of course. I have been looking for scrapers , not found any . I have just dropped the pan to baffle it , guess there is more to look at .
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This pan won’t break the bank and has crank scraper, along with some baffling.
No need to run a windage tray. I wish I had taken some pics of inside of pan, as it’s easy to duplicate what they’ve done.
Still a nice pan for the money

525C91BE-5DDB-4793-8DBB-27F3C09039B2.jpeg
 
12swinger said:
This pan won’t break the bank and has crank scraper, along with some baffling.
No need to run a windage tray. I wish I had taken some pics of inside of pan, as it’s easy to duplicate what they’ve done.
Still a nice pan for the money

View attachment 1715449524
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Yes Thank´s . I checked their website and there are some good pic´s. i´ve got work to do . Pic of current engine . Guess i must make a better oilpickup to.

IMG_20170608_163248.jpg


IMG_20190911_213947.jpg
 
SWED67barracuda said:
Yes Thank´s . I checked their website and there are some good pic´s. i´ve got work to do . Pic of current engine . Guess i must make a better oilpickup to.

View attachment 1715449564

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If you use that pickup, makes sure it's touching the bottom of the pan when it goes together. Don't leave it off the floor of the pan.

It's an interference fit. You shouldn't need to pull the pan down with a 3/4 inch impact, but you should have the pickup touching the pan floor.
 
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