I started messing around with my front motor plate install on a junk LM7 engine just to start getting an idea of the fitment and am confused by the alignment of the left side cylinder head. I hope you can see in the picture that the front of the head sits noticeably forward of the front of the block. This is going to keep the motor plate from sitting flat against the block, so I don't see how this is sturdy and especially how the water passages are going to seal. Is the gasket that thick? Or is this head mispositioned?

 

The head can't really be "mispositioned". After all, the bolt holes have to line up, including the ones with the dowel sleeves.

You may have to trim the plate so that it sits only on the block butt clears the heads completely.

 

Yeah, that's what I thought. But still, most of the commercial front plates that I see advertised are wide enough that they cover the head so I don't know how people are doing this. On my prototype that I made myself, I used an end mill and removed enough material to make a recess in the plate for the head to fit into. I suppose that I can do that again. Thanks.

 

The mock up you’ve got there, for some reason is extremely exaggerated from an alignment perspective. I build a decent amount of LS engines, and the block/head relationship is typically perfect on drivers side. The probables I see for you here is that either the front of the block has been milled a lot…which I doubt…very unlikely. Or the dowels aren’t on the deck and the head has floated forward when you snugged the head down. if your mocking this up to weld in mounts for the motor plate, I think I would pull the head off and check for dowels. If they are there, then I’d bolt the plate to the block alone, and leave the head off. Ultimately if you end up with the plate mounts too far to the rear, you can use a thin spacer to move the engine forward for alignment.

 

Che70velle, thanks for that feedback. I should have some time next week to pull the head and see what's going on. I'll post back when I'm done.

 

Just to wrap this up, I pulled the head today and the dowels were there. Weird. The head just sits that little bit forward.

In any case, it's only a mock up so I'm not going to worry about it anymore. I pulled the dowels out so that I could move the head back flush with the block and bolted the head back down. I'm going to move on with all of the other fitment work that needs doing and I'll readdress this when I get my real engine, junkyard or crate, TBD. Thanks for the feedback.

 

If it was mine, I'd trim the plate ANYWAY, since you have no guarantee that any block & heads you might need to bolt it to someday, won't have the same thing going on as your alignment mule. Won't hurt anything, butt might save ONEHOLYHELLUVALOTTA trouble on down the road someday.

 

Update on this project now that I have moved from prototype to Version 1.0 of my front plate. It turns out that a properly torqued water pump gasket is 57/1000's. I don't know how that compares to the original offset of the head vs. block that I had because I didn't measure before removing the dowels and repositioning the head. But just posting for information, a compressed water pump gasket is 57/1000" thick.

Just happy to have some time to work on this project again. Below are some photos as of this afternoon. The front plate is installed and the engine is bolted to the tub which came from a G Force GF-05 Indy car.

Now that everything is reassembled, I can re-attach the floor (undertray) and move on to the the lower frame rails of the rear sub-frame.