Anyone seen main cap block like this before ?

Looking to do some work (rebuild) on my engine and from original builder found some make shift style main cap support blocks ? (cap 2 / 3 / 4)

Good ? Bad ?, if I am to remove them then would need to change bolts etc then ?

Cheers

Wow, there's some old school stuff right there.  Main cap straps.  Some people mill the top-center of the main cap flat so that the strap seats against the top of the cap squarely--your cap straps are actually radiussed to fit around the stock configuration main caps.  The set screws are to set the cap preload (ie, fine tune the strap fitment) after the main bolts are torqued.

There's nothing wrong with your setup, but with what we've all learned over the years it might not be necessary for your particular build. Whether or not it should be reverted back to stock or left alone is up to you.  It doesn't have to be messed with and I would probably leave it as it is...a lot of work went into that old-school upgrade it's kinda cool from a retro stand point.

Ok Thanks for info, any info on how to adjust the preload / strap ?

Rob

bigblockfordfxstb wrote:Ok Thanks for info, any info on how to adjust the preload / strap ?

Rob

I couldn't tell ya because I didn't design and build that cap strap setup, and therefore cannot see how it all goes together. For example, how is the tip of the cap screw shaped?  Does the cap screw butt directly against the main cap's exterior or does it thread partially into the main cap and tie the cap and strap together (cinched with the jam nut)?  Or is it something entirely different?  I cannot make a recommendation without first evaluating and understanding the builder's intended target and design.

Take enough of these old school customized engines apart and you will observe all kiiiiiiinds of creative (and sometimes wacky) ideas.  Take it apart and figure it out.

Sure and thanks for reply...

The pain is I don't have access to motor at moment so not able to play with it..(few 000 miles away)

From what I recall (I have disassembled this all now) The main caps appear to be stock , no grind or modifications.

The cap blocks appear to have been arched to hug the top of the cap, it also had file marks on some spots to get the surfaces close as possible to each other from what I can tell, but looking at a picture zoomed in, it looks like the ends they are machines flat with the bolt surfaces, and it appears to have a slightly raised arch above the cap arch?

The hex bolt appeared to be pressing on the cap, and then locked into to position. No specific hole or groves in cap to accommodate for the bolt end from what I can recall...

Next time, I do some more investigations and check with machinist blue or a flash light for surface contact or not ?

Guess the cap would be torqued, then some slight pressure applied with the bolt and then locked down ?

Bad focus on one pic...

thanks
Rob

Note that the cap straps have punch marks to specify which main cap they go over, and also have arrows to specify which direction they are installed. They are custom fit to their respective main caps.

Install onto the bare block and torque the main bolts to spec.  Measure the main bores.  I imagine they will be in spec (3.1930"-3.1922").

If so, then don't mess with it.

Based on what I can see in the pictures, my speculation is that the set screws are supposed to be backed off, install straps over main caps and torque to spec, then turn the set screws in finger tight/lightly touching cap exterior, then cinch the set screws in place with the jam nuts.  Note that the set screws are not supposed to preload/press down on the main cap and distort the main bore--that would be unwise for several reasons.  The set screws are probably there to act similar to an index finger holding a vibrating part in place.  If that's what the overall setup is, then I wouldn't have done it that way.   But then again I would not have bothered with cap straps in the first place.  The use of the Grade 8 bolts is nice--most people would have switched to main studs which I feel is a no-no on the big power 2-bolt blocks.

Pictures don't work for me. I can't offer any advice, but would like to see what you have.

Jess

X2

X3 no workie

Roush used to sell those kits. Paul is right that his had a flat on the cap but he wasn't the originator of the idea.

http://www.network54.com/Forum/74182/thread/1368493963/O-T+but+did+any+FE-s+ever+get+these+Main+Cap+supports

I've seen these before and if I recall, the center bolt was preloaded against the cap and then the mains were honed. You might not want to start unscrewing them till you know (if you can find out) if that was the case for yours.

Great info, thanks for the reply !!!

As for Mike,Frank,Jess not sure why the pics dont work ?

Either way you should be able to head over the to source.... try goto the following URL - CUT/PASTE - then you can click left / right for other pics also...

https://2img.net/h/i77.photobucket.com/albums/j55/uotinam/maincap5_zpsbp0oehlm.jpg



@scott - yes they do kind of look the same?!

Will post some more pics...

Cheers all
Rob

on the rh side, share this photo. Click on the bottom box (img) it should say copied.
post in here.

bigblockfordfxstb wrote:Great info, thanks for the reply !!!

As for Mike,Frank,Jess not sure why the pics dont work ?

Either way you should be able to head over the to source....  try goto the following URL - CUT/PASTE - then you can click left / right for other pics also...

https://2img.net/h/i77.photobucket.com/albums/j55/uotinam/maincap5_zpsbp0oehlm.jpg



@scott - yes they do kind of look the same?!

Will post some more pics...

Cheers all
Rob

If you click on "Direct" and then "IMG" and paste in your post the picture will show up in your post.

Jess

You've already done the hard work hosting the photos.
Just need to copy & paste the right link.
See above.

Weird.... the pics show up in all my posts when I view them ?

This was selecting 'direct link'
https://2img.net/h/i77.photobucket.com/albums/j55/uotinam/compressions_zpsedkv5rlx.jpg



This was selecting IMG

Why would somebody go through all that trouble.. esp with factory rods..? kinda look like car rods too...?

I guess it was ok at the time ?

Has head porting from what I know (or can tell) and the chambers polished and cleaned up also...

Block outside had been like deburred

R

torino501 wrote:Why would somebody go through all that trouble.. esp with factory rods..? kinda look like car rods too...?

I'm guessing because there was little to no performance parts for the 429/460 back in the day, do what you gotta do to make them live

Probably would work better than the main cap girdles that get sold now.