Billet Main Caps

[Danny Bellmore]

I've been looking around at what's available for billet main caps, and all I seem to come across are 4-bolt splayed designs. I'm not sure if that's the best route to go, so I'm reaching out to see what others think. Is this a solid option, or are there downsides I should be aware of? Just trying to get a better understanding before I make any decisions.

 

[NC Engine Builder]

I've been looking around at what's available for billet main caps, and all I seem to come across are 4-bolt splayed designs. I'm not sure if that's the best route to go, so I'm reaching out to see what others think. Is this a solid option, or are there downsides I should be aware of? Just trying to get a better understanding before I make any decisions.

My opinion is that if you think you need better caps, then you probably should be looking for a better block. Aka....X, R3 or ritter

 

[GTX JOHN]

I agree.

However, some classes in NHRA do not allow aftermarket stuff.

 

[Danny Bellmore]

My opinion is that if you think you need better caps, then you probably should be looking for a better

I think Ritter may be the better option or roll the dice and run it with studs and stock caps.

 

[TT5.9mag]

There are a lot of arguments made towards the splayed 4 bolt caps weakening the factory block at a critical point. Those arguments say the stock two bolt caps are stronger. Some also say to use the 4 bolt caps and not drill the splayed outer holes. What are you trying to do? How much power do you anticipate making?

 

[Danny Bellmore]

There are a lot of arguments made towards the splayed 4 bolt caps weakening the factory block at a critical point. Those arguments say the stock two bolt caps are stronger. Some also say to use the 4 bolt caps and not drill the splayed outer holes. What are you trying to do? How much power do you anticipate making?

I would be happy with 650-675. I’m just looking for longevity. This hobby is starting to get very expensive.

 

[9secRR]

tvt59 is over 700 hp with his SB. i would talk to him. i believe that engine has been together for 4 years and still running real strong.

 

[Jersey Devil]

I've read alot of people saying that it weakens the block...But I have NEVER seen anybody post pictures proving it. I've been trying to find out how small are the Splayed bolts. They are either 7/16 or 3/8 by Milodon's installation instructions. If the bolt enters the block slightly on the blockside vs. Bulk/main part I see no weaking...no to mention they only go in <1".

Other option is a girdle.

 

[Demonracer]

Post more information about the car, the drive train and what you plan to do with the car.

 

[Danny Bellmore]

Post more information about the car, the drive train and what you plan to do with the car.

1971 Dart bracket car, 421 ci 13.5 to 1 comp, Bloomer heads, cam will be a custom grind from Bullet, 904 trans, 8.75 rear end with 410 gears or maybe 430's. Car weight 3250 with me in it and I plan on trimming that down some.

 

[TT5.9mag]

I would be happy with 650-675. I’m just looking for longevity. This hobby is starting to get very expensive.

Find a good 360 block, have it sonic checked, have top quality machine work done, and assemble it correctly. And send it. Keep it out of detonation at ANY cost and you’ll be ok.

 

[Demonracer]

My Demon is 2500 lbs in race trim with 5 gallons of fuel and me in it. My 408 puts out 523 at the flywheel and runs 10.30s, but there is probably more there. I'm building a copy of a Hennesy 416 that went 9.40 in a 2800 lb car, I'm hoping to make the low 9.00 area with the 416.

 

[Newbomb Turk]

If you are going to use aftermarket caps (I would because ANYTHING you can do to stiffen the bottom end up a bit helps) I would call Ritter and order a complete set of his billet caps. All 5 of them.

His caps are excellent and the number 5 main is fully machined as far as all the grooves machined in it so that saves a bunch of money at the machine shop.

Cut the outer bolts off the three center caps and go.

Don’t waste your money on a girdle. They are good for getting your wallet lighter and nothing else.

 

[Zigtf216]

Fill it

 

[Ironmike]

Other option is a girdle.

What I've been running. PROPERLY done, Zero main cap walk. Others poo poo the idea, but there's a big difference from one bolted on and one installed correctly. A lengthy time consuming install but well worth it.

 

[Newbomb Turk]

What I've been running. PROPERLY done, Zero main cap walk. Others poo poo the idea, but there's a big difference from one bolted on and one installed correctly. A lengthy time consuming install but well worth it.

It’s funny this came up again.

Brian Salter did a video where he uses a roll pin to secure the caps.

That is way more effective than a girdle or anything else that moves the loads from a cap that has the load to a cap that doesnt.

 

[lead69]

If you are going to use aftermarket caps (I would because ANYTHING you can do to stiffen the bottom end up a bit helps) I would call Ritter and order a complete set of his billet caps. All 5 of them.

His caps are excellent and the number 5 main is fully machined as far as all the grooves machined in it so that saves a bunch of money at the machine shop.

Cut the outer bolts off the three center caps and go.

Don’t waste your money on a girdle. They are good for getting your wallet lighter and nothing else.

Don't forget that Ritter's caps are out past the factory register

 

[Newbomb Turk]

Don't forget that Ritter's caps are out past the factory register

That’s true, but if the cut off the outer bolts they can put the registers where they go.

 

[Bobzilla]

If you are going to use aftermarket caps (I would because ANYTHING you can do to stiffen the bottom end up a bit helps) I would call Ritter and order a complete set of his billet caps. All 5 of them.

I was able to speak to Ritter in person at the Indy swap meet and he confirmed he will sell the caps as you suggest. So this IS still a good option. They are made in batches so not always on the shelf ready to go, but can be ordered.

 

[Danny Bellmore]

If you are going to use aftermarket caps (I would because ANYTHING you can do to stiffen the bottom end up a bit helps) I would call Ritter and order a complete set of his billet caps. All 5 of them.

His caps are excellent and the number 5 main is fully machined as far as all the grooves machined in it so that saves a bunch of money at the machine shop.

Cut the outer bolts off the three center caps and go.

Don’t waste your money on a girdle. They are good for getting your wallet lighter and nothing else.

I spoke with Kent today and he does not do the caps individually any longer . He feels it compromises the integrity of the stock block. He stated a stock block could not handle any more than 600hp either way. He suggested I purchase one of his blocks and have the machine work done by a reputable machine shop. He figures the cost is in the $6500.00 area complete.

 

[Danny Bellmore]

What I've been running. PROPERLY done, Zero main cap walk. Others poo poo the idea, but there's a big difference from one bolted on and one installed correctly. A lengthy time consuming install but well worth it.

What is your process on how you install the main caps?

 

[9secRR]

I would be happy with 650-675. I’m just looking for longevity. This hobby is starting to get very expensive.

if you are looking for longevity then i would take Kent's advice and buy his block. do it once and be done with it.

 

[67valiant 100]

The new owner of Pro-Gram Engineering, Billet Speed Works, can make the caps if you contact them. I had a complete 340 2 bolt set made last year. Be forwarned, it will take several months and are NOT cheap. You can opt out of the billet rear cap and save a good bit. But if youre gonna go through the trouble you might as well go all out and do it right.

I only did it because a production block is significantly lighter then an X or R block. If youre not confined by a particular class, I would go with the X or R block.

 

[TT5.9mag]

Brian Salter did a video where he uses a roll pin to secure the caps.

Can you post a link please. I went to his channel and looked for a title about main caps but didn’t find one.

 

[TT5.9mag]

The new owner of Pro-Gram Engineering, Billet Speed Works, can make the caps if you contact them. I had a complete 340 2 bolt set made last year. Be forwarned, it will take several months and are NOT cheap. You can opt out of the billet rear cap and save a good bit. But if youre gonna go through the trouble you might as well go all out and do it right.

View attachment 1716391165

I only did it because a production block is significantly lighter then an X or R block. If youre not confined by a particular class, I would go with the X or R block.

Those are very nice. Can you share cost? Their website doesn’t list anything for small block mopar any longer.