Home › Forum › Ask A Member › Newbie Questions Restoring 1957 Johnson 18hp FDE-11 › Re: Newbie Questions Restoring 1957 Johnson 18hp FDE-11
Why is that Jerry? Why do you suppose it works on the older but not the newer?
Well for one, the older OMC engines (for example) are smaller, and much easier to put together. When using the 3M847, you have to get the halves put together immediately after applying the product. On the larger V4 and V6 engines, the anaerobic sealer has an almost unlimited work time… no need to worry about it becoming tacky.
I guess one of the big differences I have ignored mentioning is that the older/larger engines that used the 847 also used spaghetti seal. So, it is the spaghetti seal that was doing the actual sealing, the 847 was just used to hold the spaghetti seal in place. So, I guess the old rule from OMC holds true: Any crankcases that use spaghetti seal, use only the 847 to hold it in place. Newer blocks (79 and newer on larger engines) with no spaghetti seal should use only the gel seal anerobic sealer. The comments made about the 847 drying too quickly are absolutely true, there is no way you would get a V6 crankcase torqued up before the 847 dried and shimmed the block halves apart a bit causing leaks.
On the smaller crankcases (old and new), that never used spaghetti seal, use either sealer.