Thread: Timing chain rubbing on front of block

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I am running a '72 400 SBC and came to find out that my double roller timing chain is rubbing the front of the block just above the center oil galley plug. Do all small block chevys need clearanced there when running a double roller chain set

yep this needs to be checked when building if it hits its wears on block if so it needs to trimed so it clears block

Muck the area up with thick grease, such as wheel bearing grease and work on it with a large diameter rat-tail file. The grease will retain the filings. If you use a grinder to relieve it, you'll throw debris everywhere.

Just a note - SB Fords too will occasionally have that problem though usually down the open side of the chain, and on the LH side of the block. You either grind a clearance as suggested or go back to a single chain system. Why not just tape and mask off the area (after doing a good oil removal cleanup) and go at it with a grinder. You can do a lot better/faster job that way

i would think that the front plug s out of the block and that it looks clean no oil New cam bearings ..your putting back to gether so stuff a rag in the cam bearing hole and die grinder is used most all the time to clean up this spot of the block as this is lower then the timming cover you will have a very hard time using a file in that part of the block hand drill and a stone work s good to just wash the block good after no big deal ?

I don't remember a case of ever seeing that on an 70s 400----------did your timing gear/chain possibly have some thrust washers you didn't install??????

Plus---its difficult to grind or file anything with thick grease------

i done many... chain hits some blocks allways check it if going dual roller. some chain sets the upper gear is not inset as much as other timming set s .i have radius the upper back face of gear on the lathe as well it.s not much just break the edge on the back of gear face

From the looks of it, seems to me most of the clearance needed has already been established. Some trimming and smoothing, general clean up will probably get it where it needs to be.