Mustang and Ford Performance Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 · (Edited)
I am rebuilding my MMR 4.75 and don’t understand the thrust bearings. I spoke to MMR today about the 2 blue shims that are needed that go between the cap bearing and the main cap, 1 on each side. With the main cap torqued the shims are loose and seem like they will fall out. MMR said to dimple just the main cap in 3 spots on each side to keep the shims from moving. I feel like the shim AND the cap should be dimpled together to keep shims from moving. Has anyone installed them before. They are the Romeo block 2v bearings
 

Attachments

·
Administrator
Joined
·
9,417 Posts
This particular modification is MMR's approach to installing a modified Coyote crank into a 4.6L Modmotor for a small displacement increase and a corresponding small reduction in the cost of a crankshaft. The particular modification has been the source of more than a little heartburn among users over the years. Some of the problems encountered in rebuilds are what you are experiencing right now. Some are associated with the narrower oil sealing surface the Coyote crank uses in order to make room for the rear mounted reluctor timing wheel, Some of the problems are associated with guys who finally gave up and went back to a standard 4.6L crank only to find they now needed to replace their pistons because of the difference in stroke between the two crankshafts. There are other challenges also.

In general it is to your advantage not to embrace these sorts of solutions unless you are fully versed in the distinctions between the two different builds and are both OK with them and capable of managing them on your own in an ongoing basis moving forward. A number of builders will not work on engines with these sorts of mods because the increased potential for an unhappy compared to using standard 4.6L 'stuff. Others either feel they are up to the challenge and / or throw caution to the wind. Either way your best bet is probably to embrace the not so service oriented MMR customer service solutions they offer. I know this is somewhat bitter medicine but, it does come with the territory when you elect to pursue these sorts of modifications to the basic engine design model with providers like MMR.


Ed
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #4 ·
I spoke with Greg At MMR. They are sending me different thickness shims. I currently have .063 shims. I pulled my old shims out of my original MMR block and they were .070. The .070 are nice and tight and 1 shim was dimpled in 3 spots by MMR. Now it's a new issue. WithMy new used Romeo block the crank is hitting and the block needs to be clearanced by the #1 main cap. Notified MMR and they said some blocks did need clearance

- - - Updated - - -

Email from Mmr
 

Attachments

·
Administrator
Joined
·
9,417 Posts
Well, there you go! Looks like you are all set.


Ed
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #7 · (Edited)
Does the thrust bearing fully flanged mod you recommend work with a Romeo iron block and 4.75 crank. Bearing set MB5219SI to use just the upper #5.
 

·
Administrator
Joined
·
9,417 Posts
King does not make a fully flanged thrust for your application. If you want to use one you need to buy two sets of bearings, probably from MMR at MMR pricing, and modify the lower from the second set to look like the upper from the first set..The modified Coyote crank will require a custom #5 main for your block. As painful as it is your best bet is to go back to the customer service experience at MMR — their crank design, their fix. In the future you would be better served not to embrace this sort of modification.


Ed
 

·
Registered
Joined
·
2 Posts
I have a teksid block 4.75 stroker from mmr it’s a 1000se, and I am now curious and a bit worried about this thread I just bumped into. I was going to have my block taken apart and pistons changed to go higher compression and maybe upgrading rods to the weisco boostline set up, I’m scared these spacer they use could be a very weak point of this block and can cause engine failure after it’s taken apart and rebalanced and reassembled by a local performance shop. I have a lot of money in my build, trickflow 44cc 185r heads ported, and going to be a boosted built with stage 3 MHS cams, last thing I would want is all my money down the drain. I am new to the whole mustang scene coming from Hemi platform. Picked up a nee edge mustang for dirt cheap and started to build it appearance, suspension, and just fukk out making the convertible stuffed chassis wise and what not, did not even know that people were doing coyote swaps in these cars and wish I would have just spend my money towords that side of things lol but hey what can ya do. Also starting to learn that mmr has a very bad reputation in the industry for some reason...... I find the block to look stout and built good
 
1 - 9 of 9 Posts
Top