Focus Fanatics Forum banner

1 - 14 of 14 Posts

·
Wales!!
Joined
·
10,218 Posts
Discussion Starter · #1 ·
i bought a block on the forum and it was missing main caps. my engine machinist says i cant use them from another engine, and that i have to use an entire different block. is this true?

i already have money in this block and i cant believe the machinist is telling me that the block i currently have is useless.
 

·
I <3 my SVT
Joined
·
1,761 Posts
Thats bologne. A good machinist should be able to take used end caps, machine a few thousanths off the face of the cap and rebore it out. Basically the same thing with a damaged journal... Just recut it.

Even at worst case scenario, they could cnc some new caps and line bore according to your crank... How does/did jay racing make billet mains, sight unseen? I would certainly call performance shops around and see how they do things.

Matt
Posted via FF Mobile
 

·
FF Affiliate
Joined
·
31,171 Posts
Actually your machinest is correct , The duratec has a main cap set not single main caps that he could go throug 15 to 20 caps move them around and get enough caps to make work
The Duratec block with out the origional main cap set is junk , you could have 20 main sets and the chance of one of them working is very very slim

Tom
 

·
Vinyl + LED guru
Joined
·
4,243 Posts
Why could it not just be honed? I don't see the problem there.
It works for the zetec and most other engines when rebuilds are done....
 

·
I <3 my SVT
Joined
·
1,761 Posts
Yea i dont see why you cant machine existing caps... How did they do it from the factory, make a cast or?

Matt
Posted via FF Mobile
 

·
Registered
Joined
·
177 Posts
As Tom has already stated, the Duratec doesn't really have "main caps". The lower crankcase pretty much makes up the caps if you get what I'm saying, the "caps" are really just a single piece of metal that you bolt to the upper crankcase in order to hold the crankshaft and the bottom half of it's bearings in place. There are no individual caps like there are with the camshafts or the zetec which is a totally different animal on its own.
 

·
Sückn' n Blown
Joined
·
7,747 Posts
The Duratec uses a main girdle. It is all one piece.



Older engines that use individual main caps let you pick and choose which ones to use, so you find the right ones to meet the clearances for each journal.

With a single main, you cannot interchange them. So if one ends up being too big, you cannot change it with a different one, you would need a whole different girdle. If one was too tight, it might be possible to bore it, but that is only if all the others are correct.

So essentially, you need the main that came with the engine.
 

·
I <3 my SVT
Joined
·
1,761 Posts
ahhh now i get it. I'm sure it could be done if one were to custom cnc one, but I doubt its worth the cost.

Looks like a poor design to me, what is the advantage to making it this way? I dont see how its better than individual mains.

Matt
 

·
Wales!!
Joined
·
10,218 Posts
Discussion Starter · #13 ·
thank you guys. you explained it a lot better than my machinist. im going to use my old block, that i cracked a rist pin. worse case my machinist will put sleeves in it.
 
1 - 14 of 14 Posts
Top