NEW Ductile Iron Main Cap Sets for 360's

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whitepunkonnitro

whitepunkonnitro

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Great insurance for Stroked, Blown or Sprayed 360 engines. Brand new MOPAR PERFORMANCE four bolt main cap sets come with Ductile Two bolt #1 cap, Four Bolt replacements for #'s 2, 3 and 4, and all the new main bolts needed to screw it all together. Better than twice the tensile strength of the stock cast caps!
Have several of these packages, asking $125 shipped anywhere in the continuous 48 states.
PM me if interested, and THANKS FABO!
 
Does this include the rear main cap?
 
(note) SPLAYED VS. STRAIGHT

Several people have asked me if these are spayed or straight bolts. They are STRAIGHT, and in this application, straight is better. If you look at the main cap bulkhead, where it ties into the oil pan rail on your 360, you'll see that there is a divit there. A splayed bolt cap would put the load from the additional bolts into the thinnest part of the structure, actually removing meat from the casting where it is needed the most.
Also, the benefit of these caps is not so much the added strength of the outboard bolts, but rather the upgrade in material over stock. You could cut the extra bolt bosses off these caps and you would still have a unit more than twice the strength of stock.
Horsepower does not break cast caps, but detonation does. If your combination is blown, turboed, sprayed, or is just a high squeeze pump gasser, sooner or later it's going to rattle...and these things are your best bet for keeping the crank inside the oil pan!
 
I'm not trying to start an arguement here, but there's not enough meat there for a straight second bolt in a production block. Half the bolt will be exposed. Because of how the block is made, only a small portion of the block will have threads all the way around on that second bolt. Go look at a production block and you will see. Most people just saw off the outside bolt ears on the three inner caps to use these.
 
StrokerScamp said:
I'm not trying to start an arguement here, but there's not enough meat there for a straight second bolt in a production block. Half the bolt will be exposed. Because of how the block is made, only a small portion of the block will have threads all the way around on that second bolt. Go look at a production block and you will see. Most people just saw off the outside bolt ears on the three inner caps to use these.
Click to expand...


No arguement, just good tech discussion...
I have to disagree on a couple of points. For openers, a standard pitch bolt requires the equivalent of its diameter for minimum thread engagement (ie, a 1/2" bolt should have at least 1/2" threaded depth). In the case, there is more than enough meat in the bulkhead to accomplish this.
Secondly, the purpose of the additional bolts is only partially to support the main saddle in its vertical plane. The idea is to keep the cap from walking and twisting sideways and attempting to split the saddle like a log. Example of this are the 3/8ths cross bolts found in the 426 Hemi. These do zero to support the actual main line of the block, their only job is to keep the cap from walking. If you take a dual cross bolt Hemi, like a KB for example, torque all four cross bolts in place, but leave the vertical studs out, it only takes a few moderate hits with a hammer to move the cap fore or aft in the bulkhead, but twisting it is impossible.
 
All good points...and I agree....but here's the thing. When people convert Mopar small blocks to aftermarket mains, they are gonna test it all to the absolute max. I've seen them drilled and it's just too scary lookin for me blood. ....we still might get a set from you to use as two bolt mains though. He aint made his mind up yet. lol
 
The only main cap I ever broke was the #5. I believe that all the holes in them and machineing for the oil pump weakens them. A steel replacement would be the cats @%#&*.
 
pic
7017969255_eea1506d83_m.jpg


(bolts included but not shown)
 
dart6 said:
i might be interested in a set but what can i expect to pay to get the reliefs machined thx
Click to expand...

Depends on the relationship you've got with your machinist. I would think having the thrust surface machined would be part of the standard proceedure and price for fitting aftermarket caps.
 
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