Milodon 4 bolt main caps on a dove-a block

do just the holes need to be drilled and tapped or does the step/pad need to be machined down also ? in the pic of them they look like a bolt down deal just need six holes drilled and tapped and then line honed.

the register depth needs to be correct...i cant remember what it is though

Thanks thats what i wanted to know.

I had bought these caps and intended to to install them but at 300 for the caps and 300 to install with drilling the holes, setting register depth align bore and align hone, I just bought and aftermarket block. now remember that those Milodons are designed to be installed on Thick web blocks only.. but I hear the the CAT caps on a dOve block are cheaper and just as good but a little harder material and the align bore is an iffy deal with some machine shops.. but thats just what I heard so...

The "CAT" caps work fine, and can be put on non DOVE blocks with a small spacer under each end. Paul Kane has posted good pics of this proceedure being done, and it works perfect. DOVE blocks don't need the spacer as the block is cast to the pan rail. They are therefor easier to do a 4 bolt conversion on , and are a stronger block because of the webbing. The inexpensive caps have shown to be good pieces, the Cats, Falcons, Crank Shaft Depot , TMD, etc. We have heard the material on some has to be machined in smaller less aggressive cuts, but thats it. The finished product turns out fine. The real trick is to find a machine shop that is experienced in doing 4 bolt conversions. If they do them often, you get a better job, and a set price not an hourly rate while they experiment on your block.

nuclearcobra wrote:do just the holes need to be drilled and tapped or does the step/pad need to be machined down also ? in the pic of them they look like a bolt down deal just need six holes drilled and tapped and then line honed.

Yes, there is a spec for main cap register gap for the outer bolts. Normalyy, the block is not machined for this clearance, the outer registers of the splayed caps are. Usually preferred to be 0.001"-0.003" depending on who does the conversion, etc. Instructions should come with the caps, and/or most any competent shop that is experienced in converting to 4-bolt caps should know how to do it. Way too much to go over right here and now. I like 0.001"-0.002"; you need to mock up and measure, then cut the caps down as needed.

Paul

138 wrote:... but I hear the the CAT caps on a dOve block are cheaper and just as good but a little harder material and the align bore is an iffy deal with some machine shops.. but thats just what I heard so...

blown473 wrote:The "CAT" caps work fine, The inexpensive caps have shown to be good pieces, the Cats, Falcons, Crank Shaft Depot , TMD, etc. We have heard the material on some has to be machined in smaller less aggressive cuts, but thats it. The finished product turns out fine. The real trick is to find a machine shop that is experienced in doing 4 bolt conversions. If they do them often, you get a better job, and a set price not an hourly rate while they experiment on your block.

We just finished another 4 blocks: 3 D0VE-A block 4-bolt main cap conversions + 1 D9TE block 4-bolt main cap conversion with the spacers. I have always like the CAT caps because of their design, and also because I have disliked so much about ProComp in general...BUT I have to say at the time of this writing that the Procomp caps are going to be our preferred aftermarket offshore cap for the time being until CAT fixes something that we have heard about but not experienced ourselves (until now). Read on...

I have regularly suggested the CAT caps over the ProComp caps because they come with the outer bolts and also the drill pilot for drilling the outer splayed bolt holes into the block....the ProComp caps do not include these parts.

WELL, we just did the 1 D9TE block with the ProComps and the 3 D0VE-A blocks with the CATs. The Procomp capped D9TE block align-bored very easily, as expected, and it also align-honed beautifully as well. The CAT's were a nightmare by comparison. Chewed up bits no matter how light a cut we took, and there were no machine lines whatsoever after the cut (looked polished as glass). The CATs are hard as a rock. Although we don't know for sure, we suspect that they are getting heat treated overseas, which makes them way too tough to cut. Now we understand what everyone was complaining about with the CAT caps. Van talks to the owner of CAT all the time (weekly basis) and this main cap hardness matter will be brought up with him.

The Good News: the offshore main caps have an unfinshed main bore diameter of about 3.05", and so fortunately after cutting into the CATs to about a 3.15" diameter (remove .050" depth of material), the hardness of the (presumed) heat treat is gone and they being to machine normally again. So in the end, the CATs are fine....but getting to that point takes forever with a LOT of small cuts.

If you used CAT caps for your conversion and you are taking the block to a machine shop for align-bore/align-hone, be sure to enlighten the machinist of what he may observe with these caps (give him a heads-up) so that he may adjust his cutting depth, cut slower, etc., until he is past the hard surface. Otherwise you will get an earful when you pick up your block.

Hopefully, this is a temporary deal and future batches of CAT caps will eventually be non-heat treated steel.

Paul

Paul Kane wrote:

138 wrote:... but I hear the the CAT caps on a dOve block are cheaper and just as good but a little harder material and the align bore is an iffy deal with some machine shops.. but thats just what I heard so...

blown473 wrote:The "CAT" caps work fine, The inexpensive caps have shown to be good pieces, the Cats, Falcons, Crank Shaft Depot , TMD, etc. We have heard the material on some has to be machined in smaller less aggressive cuts, but thats it. The finished product turns out fine. The real trick is to find a machine shop that is experienced in doing 4 bolt conversions. If they do them often, you get a better job, and a set price not an hourly rate while they experiment on your block.

We just finished another 4 blocks: 3 D0VE-A block 4-bolt main cap conversions + 1 D9TE block 4-bolt main cap conversion with the spacers. I have always like the CAT caps because of their design, and also because I have disliked so much about ProComp in general...BUT I have to say at the time of this writing that the Procomp caps are going to be our preferred aftermarket offshore cap for the time being until CAT fixes something that we have heard about but not experienced ourselves (until now). Read on...

I have regularly suggested the CAT caps over the ProComp caps because they come with the outer bolts and also the drill pilot for drilling the outer splayed bolt holes into the block....the ProComp caps do not include these parts.

WELL, we just did the 1 D9TE block with the ProComps and the 3 D0VE-A blocks with the CATs. The Procomp capped D9TE block align-bored very easily, as expected, and it also align-honed beautifully as well. The CAT's were a nightmare by comparison. Chewed up bits no matter how light a cut we took, and there were no machine lines whatsoever after the cut (looked polished as glass). The CATs are hard as a rock. Although we don't know for sure, we suspect that they are getting heat treated overseas, which makes them way too tough to cut. Now we understand what everyone was complaining about with the CAT caps. Van talks to the owner of CAT all the time (weekly basis) and this main cap hardness matter will be brought up with him.

The Good News: the offshore main caps have an unfinshed main bore diameter of about 2.80", and so fortunately after cutting into the CATs to about a 2.90" diameter (remove .050" depth of material), the hardness of the (presumed) heat treat is gone and they being to machine normally again. So in the end, the CATs are fine....but getting to that point takes forever with a LOT of small cuts.

If you used CAT caps for your conversion and you are taking the block to a machine shop for align-bore/align-hone, be sure to enlighten the machinist of what he may observe with these caps (give him a heads-up) so that he may adjust his cutting depth, cut slower, etc., until he is past the hard surface. Otherwise you will get an earful when you pick up your block.

Hopefully, this is a temporary deal and future batches of CAT caps will eventually be non-heat treated steel.

Paul

and there you have it...

If you choose to use the Milodon caps, and decide to do the drilling, and tapping yourself, as Milodon claims you can do at home. I did this part myself on a D0VE-A block, and I found some things that you should be aware of. They provide you with a drill bushing for accurately locating the holes, they instruct you to use a 3/8" drill bit - DON'T DO IT, you will destroy the bushing on your first attempt! The correct drill size for the bushing, and a 7/16 14 thread is a letter U drill (.368). Also, do NOT use the 7/16 14 bolts that Milodon provides, they are absolute junk, the threads are very ragged, and just love to gall, and jam up in the cast iron (I found this out the hard way), spring for the extra cost and get some quality ARP's - you won't be sorry. That's my story, and I'm sticking to it!

Wayne (SAWDOFF) Pearce

GREAT FEEDBACK GENTLEMEN!!
Am thinking of making this conversion on one of my D1's

I wish all threads were this productive.....
Regards.
Al

I did a D1 block two or three years ago, after talking to Paul with the Cat caps. I ran into the same deal when Line boring.

The machine shop I used couldn't get the bore right and my crank to center line got tighter and ended up with mu pistons out of the hole a good bit.

They were bitching about how tuff the caps were and how long it took to do the job.

Two years of shifting at 71-7100 rpm, several times on the dyno and over 15:1 compression and the brgs looked perfect. Brg bores still dead on.

Paul Kane wrote:

138 wrote:... but I hear the the CAT caps on a dOve block are cheaper and just as good but a little harder material and the align bore is an iffy deal with some machine shops.. but thats just what I heard so...

blown473 wrote:The "CAT" caps work fine, The inexpensive caps have shown to be good pieces, the Cats, Falcons, Crank Shaft Depot , TMD, etc. We have heard the material on some has to be machined in smaller less aggressive cuts, but thats it. The finished product turns out fine. The real trick is to find a machine shop that is experienced in doing 4 bolt conversions. If they do them often, you get a better job, and a set price not an hourly rate while they experiment on your block.

We just finished another 4 blocks: 3 D0VE-A block 4-bolt main cap conversions + 1 D9TE block 4-bolt main cap conversion with the spacers. I have always like the CAT caps because of their design, and also because I have disliked so much about ProComp in general...BUT I have to say at the time of this writing that the Procomp caps are going to be our preferred aftermarket offshore cap for the time being until CAT fixes something that we have heard about but not experienced ourselves (until now). Read on...

I have regularly suggested the CAT caps over the ProComp caps because they come with the outer bolts and also the drill pilot for drilling the outer splayed bolt holes into the block....the ProComp caps do not include these parts.

WELL, we just did the 1 D9TE block with the ProComps and the 3 D0VE-A blocks with the CATs. The Procomp capped D9TE block align-bored very easily, as expected, and it also align-honed beautifully as well. The CAT's were a nightmare by comparison. Chewed up bits no matter how light a cut we took, and there were no machine lines whatsoever after the cut (looked polished as glass). The CATs are hard as a rock. Although we don't know for sure, we suspect that they are getting heat treated overseas, which makes them way too tough to cut. Now we understand what everyone was complaining about with the CAT caps. Van talks to the owner of CAT all the time (weekly basis) and this main cap hardness matter will be brought up with him.

The Good News: the offshore main caps have an unfinshed main bore diameter of about 2.80", and so fortunately after cutting into the CATs to about a 2.90" diameter (remove .050" depth of material), the hardness of the (presumed) heat treat is gone and they being to machine normally again. So in the end, the CATs are fine....but getting to that point takes forever with a LOT of small cuts.

If you used CAT caps for your conversion and you are taking the block to a machine shop for align-bore/align-hone, be sure to enlighten the machinist of what he may observe with these caps (give him a heads-up) so that he may adjust his cutting depth, cut slower, etc., until he is past the hard surface. Otherwise you will get an earful when you pick up your block.

Hopefully, this is a temporary deal and future batches of CAT caps will eventually be non-heat treated steel.

Paul

Paul,
At the end of the day after doing this conversion on a DOVE-A block with your stage 1 oiling mods how does that stack up to buying the A460 block new from FRPP?
Dave

NO FAIR wrote: Paul,
At the end of the day after doing this conversion on a DOVE-A block with your stage 1 oiling mods how does that stack up to buying the A460 block new from FRPP?
Dave

Not sure I understand the question....are you asking the price of such a prepared block so as to compare to A460 pricing? If so, we sell them at the following retail price:

• D0VE-A block
  
• Thermoclean & mag check
  
• Stage 1 oiling mods
  
• Install 1025 carbon steel billet main caps
  
• Align bore
  
• Align hone
  
• Grand Total (2013)= $1249

Compared to a factory 4-bolt D0VE-A block (parallel bolts/cast caps, no oiling mods, etc), the billet splayed capped 4-bolt is almost certainly the better value from a high performance standpoint/similar pricing.

At the time of this writing, the A460 retails for around $2400, one of the above spec'd 4-bolt D0VE blocks for around $1249. Some people would say "you are half-way to an A460 block." Another way to look at it is that you could buy two 4-bolted D0VE blocks for the price of an A460 block. And so the more significant "precursor question" is: which block is best suited for the build's needs? Depending on the build, one might very well need the A460 (ie, 4.600" bore combo, etc), while on the other hand it might be complete overkill (and $1100 overspent) for a lesser build (ie, 1000 hp 557, etc). Just like all the other component options, it depends what you need.

Paul

I think that is the most asked question about the swap Paul so I appreciate you posting an accurate comparison.