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Author Topic:   installing splayed mains
Dirt Freak

Total posts: 385
posted January 08, 2005 03:41 PM  
OK - purchasing a set of splayed mains for the 400 I'm building - was wondering if anyone ever installed these themselves? They come with the drill guide to drill the outer bolts so it looks like all I've got to do is to clean the surfaces then bolt them down, then use the guide to drill the holes then tap them for the extra bolts. I'm hoping to save the extra $100 and just have a straight line-hone done after I install them.

Dirt Freak

Total posts: 205
posted January 08, 2005 05:51 PM  
me personally... I'd spend whatever it cost to do it. I'd think they are some of the most critical pieces in the puzzle. If yer dead set on doin it, take a junk block and practice with that.. I'd think you would need some variation of a mill to anchor the part as well as the drill itself to be accurate and actually do more good than harm.

Dirt Forum Champ
Total posts: 755
posted January 08, 2005 08:01 PM  
if they are quality mains then they will be larger than the stock caps by a few thousands. This is so a qualified machinist can mill enough off the block to make the caps fit TIGHT.

If you can set the caps on the block and they sit flush then they wont do any more good than stock caps, fact is they will be loose and will walk.

Dirt Forum Champ
Total posts: 562
posted January 08, 2005 08:02 PM  
Unless you have a mill don't try to install these yourself....... the steps in the block and cap must fit perfect, and by that I mean when the bottom of the step is bottomed out in the block the top of the step needs .002 of clearance, and more than that when you torque the outer bolts the bearing sadle gets out of shape if the top of the step is flushed against the block that means the bottom is NOT seated and will egg after torque also... the torque will make it egg shaped. Also extra material is in the caps so it will still need a bore, then a hone......Yes you can save a few dollars installing them yourself, and if you don't use a shop that knows how to fit them correctly you are just as well off doing them yourself.

The big deal of installing splayed caps is milling the steps correctly, when the caps fit the block is when you start drilling and tapping........ Also you can re-use caps from one block to another.........But by the time you get done clipping all the steps on a mill you have sooo much time fitting the properly you are better off just buying new ones. A good builder does about 3-5 blocks at a time, he will trial fit the caps and keep swapping them around from block to block until he gets the least amount of mill work needed then start fit-up. That is why you will see 2 sets of numbers on some caps. like 5-2 on the 2nd cap.....that means it was the 5th block in the set when the builder did multiple blocks at the same time

Dirt Freak

Total posts: 385
posted January 08, 2005 08:38 PM  
Ahh - that makes sense - didn't even think about fitting them to the block itself - guess it goes to the machine shop.

As for quality of a shop - anyone got a recommendation for a shop in Kansas City? I've used K&M in the past and was going to go back there for this one too.

Dirt Freak

Total posts: 493
posted January 09, 2005 07:14 AM  
Great info by awkwardjeff again...i will have to file that one in the mental rolodex. good post and discussion...sixwillwin

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