Big Mopar main caps
 

I'm just curious what people are using to keep the bottom end strong in a stock block.

The "trend" seems to be aluminum main caps on stock blocks over 600 hp.

My current 446" project has evolved into something that should be well above that. THe block has already been machined with stock caps and ARP studs... and I have almost everything to get the motor together. I'm wondering if it is worth the added expense to go to the aluminum caps (plus $ machining), or build what I have ... and save my duckets for a future aftermarket block stroker.

Thanks,

Rob

Re: Big Mopar main caps
 

Please save your money until you can buy an aftermarket block. Sure would be a shame to destroy the good pieces you already have invested in. They have been splitting the main bearing webbings for years. Stock blocks are OK until you reach the 630 to 650 maximum for hp. level. Checkout MOPARTS website and look for some pics.

Re: Big Mopar main caps
 

Pro Gram Engineering steel caps would be best IMO.

Re: Big Mopar main caps
 

The aftermarket block is the smart answer. My problem is that I don't want to wait that long. I've contacted several mopar engine builder gurus, one of them suggested I build it with the stock caps, no girdle. THat would save me $ 600-$700 on the aluminum cap install... and basically all I would need to complete my motor is some pushrods.

I am trying to find out about the availability of aftermarket mopar wedge iron blocks, which are currently nonexistent.

Re: Big Mopar main caps
 

We had customer years ago that had split several 440 blocks in the mains and wanted to girdle it.
We built a .625'' thick girdle,can have laser cut to your pattern and Blanchard ground,we made a set of steel caps that were tall enough that they were flush with oil pan rail,girdle attached w/oil pan bolts and several countersunk bolt around oil pan rail and main studs and had a hole in each main to pull caps with slide hammer and attach to mains also,if you make mains don't use expensive hard material,want a low grade steel it expands close to same rate as cast,but is way stronger,they ran this block many years.
Now days,unless you could do it yourself and like to piddle,I say buy a aftermarket block,that wasn't really a option back then.
Mike Taylor 3601

Re: Big Mopar main caps
 

Yes, a girdle is an option. The one in the attached link appears to be the beefiest on the market. It seems very similar to what you were describing, Mike, except with aluminum caps.

http://www.bcrproducts.com/caps_and_girdle_system.html

Of course, now your talking about $800 for the cap and girdle system... plus another $400 to $500 to install and align bore. That's a significant investment in a 40 year old block, and a decent down payment on an aftermarket block... if they existed.

Re: Big Mopar main caps
 

Don't waste your money on aluminum caps. Run what you have and start saving your money for an aftermarket block. The Mopar blocks will be out in a few months but they are so heavy. Save up for aluminum unless you can live with the weight.

Re: Big Mopar main caps
 

If I go the route of stock main caps and ARP studs, should I put a girdle on it? At least there would be no additional machining expenses.

Some people do say a girdle makes the bottom end TOO rigid.

Re: Big Mopar main caps
 

I don't believe there is such a thing as too rigid on bottom end,more stable you can keep mains the better. IMO
Mike Taylor 3601