4 bolt caps

Does anybody have a source for a flat bottom 4 bolt main cap conversion? Preferably splayed like the pro gram. So far i'm not having any luck finding the pro gram caps.

Did you try Milodon @ Summit but pricy $300
https://www.summitracing.com/int/parts/mil-11450/overview/make/ford
http://www.milodon.com/main-caps/main-caps.asp

Looks like Procomp Caps
http://www.ebay.com/itm/Ford-429-460-OEM-2-Bolt-to-4-Bolt-Splayed-Billet-Steel-Main-Caps-Middle-3-Caps-/302210808640

I may be wrong, but I remember correctly, the Milodon caps are NOT flat, they are stepped.
The last set of Pro-Gram BBF caps I got directly from Pro-Gram (nobody had them on the shelf) and it took over 2 months.

Yeah I saw those. I believe they will require a shim on bottom to work with a D1 block. I'm not crazy about the idea of shimming main caps. They need a flat bottom, the pro comp and milodon both have a step register.

I machined the ruff cast area near the pan rails flat and made a small radius in the corners to relief stress then surface ground some .200 thick flat plates to go into that area to give the cap something to sit on.

I left the plates about .0015 low to allow the cap to pull down to the register tight.

I use the Cat brand caps and had no trouble with the engine for 6 years. 860 hp and 760 tq shifting at 7100 at 15.3:1 compression.

I would machine the bearing surface area to within .020-.030 in a mill if I had it to do over, before I had it line bored in the machine shop.

Those Chinee caps are chewie as crap and hard to machine, the boring bar will try to lead into the softer cast iron of the block and cause trouble if you don't take very light cuts.

I'm to the point now where I just go two bolt up to about 900 hp and give plenty of main clearance and over that go to a after market block.

If I am nervous about a long stroke deal I will put straps on the caps. It will help cap walk, but you can still crack a main web from time to time.

stanger68 wrote:Does anybody have a source for a flat bottom 4 bolt main cap conversion? Preferably splayed like the pro gram. So far i'm not having any luck finding the pro gram caps.

Programm Engineering is the only company of which I am aware that currently offers a flat-bottom main cap.  We had a set of Programm Engineering, parallel bolt (SCJ-style) flat-bottomed main caps installed onto a D1VE block where the factory 2-bolt main cap registers were simply extended outward toward the pan rails and doweled so as to convert 2, 3, & 4 to "floating register," doweled positioning mains a la SCJ.  That D1VE block sustained an estimated 3000 hp for 7 years.  By the way, this is a testament to the cast iron block more than the caps since most any 385 Series billet cap will handle that kind of power.  With this in mind, you can use the Procomp billet caps and machine the double-register in the cast area of the D1VE main webbing and use a spacer--this does not weaken the block any more than machining that double-register into the block at the same place for a Programm double-register main cap.  We've done this mod on blown alcohol monster truck engines and even on one of our own blown nitro (60%) engines without fail.  If your engine is going to generate less power, then you'll probably be fine.

Here is a "Show & Tell" thread that goes over the general process for this modification.  You have to be logged in to see the pictures:

http://www.460ford.com/forum/37-engine-tech/106463-d0ve-splayed-4-bolt-caps-thin-web-block-yes.html

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stanger68 wrote:...I believe they will require a shim on bottom to work with a D1 block.  I'm not crazy about the idea of shimming main caps.  They need a flat bottom, the pro comp and milodon both have a step register.

See above.

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IDT-572 wrote:Those Chinese caps are chewie as crap and hard to machine, the boring bar will try to lead into the softer cast iron of the block and cause trouble if you don't take very light cuts.

We've had the same issues with the CAT caps and the the way around it is to take light, slow feed rate cuts...and yes it's a pain.  The good news is that we've since used Procomp caps numerous times and not seen this issue--the Procomp caps machine more like a billet steel cap should.

Thanks guys, I was able to get the front 4 splayed caps from pro-gram. They apparently just don't advertise them, but according to my machinist they are running another batch now. Also found engine systems in Georgia offers the boss style caps foe center 3. My machinist talked me out of using them since they use dowels to locate the cap. So I listened to the expert and bought all 4 splayed.

Paul Kane wrote:

stanger68 wrote:Does anybody have a source for a flat bottom 4 bolt main cap conversion? Preferably splayed like the pro gram. So far i'm not having any luck finding the pro gram caps.

Programm Engineering is the only company of which I am aware that currently offers a flat-bottom main cap.  We had a set of Programm Engineering, parallel bolt (SCJ-style) flat-bottomed main caps installed onto a D1VE block where the factory 2-bolt main cap registers were simply extended outward toward the pan rails and doweled so as to convert 2, 3, & 4 to "floating register," doweled positioning mains a la SCJ.  That D1VE block sustained an estimated 3000 hp for 7 years.  By the way, this is a testament to the cast iron block more than the caps since most any 385 Series billet cap will handle that kind of power.  With this in mind, you can use the Procomp billet caps and machine the double-register in the cast area of the D1VE main webbing and use a spacer--this does not weaken the block any more than machining that double-register into the block at the same place for a Programm double-register main cap.  We've done this mod on blown alcohol monster truck engines and even on one of our own blown nitro (60%) engines without fail.  If your engine is going to generate less power, then you'll probably be fine.

Here is a "Show & Tell" thread that goes over the general process for this modification.  You have to be logged in to see the pictures:

http://www.460ford.com/forum/37-engine-tech/106463-d0ve-splayed-4-bolt-caps-thin-web-block-yes.html

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stanger68 wrote:...I believe they will require a shim on bottom to work with a D1 block.  I'm not crazy about the idea of shimming main caps.  They need a flat bottom, the pro comp and milodon both have a step register.

See above.

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IDT-572 wrote:Those Chinese caps are chewie as crap and hard to machine, the boring bar will try to lead into the softer cast iron of the block and cause trouble if you don't take very light cuts.

We've had the same issues with the CAT caps and the the way around it is to take light, slow feed rate cuts...and yes it's a pain.  The good news is that we've since used Procomp caps numerous times and not seen this issue--the Procomp caps machine more like a billet steel cap should.

Paul, That's great to hear about the machining, are he Pro Comp caps in stock now?

Mark Laczo posted an ebay link above in the first reply to this thread--those are the Procomp main caps. The Procomp billet 460 caps were out of stock for a couple years but they are available again at last.  I presume they are the same cap/manufactured the same (ie, no heat treat which the Cat caps do have and makes them more tricky to machine).

Thanks Paul!!!!!!!!!

once you go this far with a block... why not just buy an eliminator block?

Because this route saves me a lot of money and will easily take the amount of power I plan to make and still be pretty much bullet proof. It would be overkill. That is one of the main reasons we use the 460 , you can build a lot of power with a junk yard donor. You do realize that an aftermarket block is not ready to use out of the box, there is still several hundred dollars worth of machine work to when delivered.

stanger68 wrote:Thanks guys, I was able to get the front 4 splayed caps from pro-gram...I listened to the expert and bought all 4 splayed.

Please post a picture of the splayed #1 4-bolt cap, I've only seen Programm's Boss 429 #1 4-bolt cap which is parallel 4-bolt, not splayed.

I don't believe a splayed cap is even possible on #1 main since the outer bolt holes will intersect front timing cover threaded holes, the oil pump mounting flange, etc (a few years ago I investigated fitting a spayed cap on #1 ).

I think your expert is mistaken...but if there is indeed a unique #1 splayed cap I'd like to see it (not that I feel it's necessary).

I will when they come in. I didn't know that the front was available either but he said it was. He said the machine work would cost the same for 3 or 4 caps so another $100 bucks didn't sound all that bad for a bullet proof bottom end. However I don't think he ever specifically said the #1 was splayed that may be my misunderstanding.