small motor refresh

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small motor refresh

Post by bikesndbugs » Thu Sep 14, 2017 10:58 pm

MY motor blows a pretty good amount of oil. just out the stock crank pressure outlet near the oil filler.
i snapped my exhaust stud on the head.

Whats the best way to replace the stud. just buy a new head?
i might try to just drill it and retap it. I have some singleport heads i could throw on but they have no vaulvetrain to them.

when i pull the heads i plan to throw some new rings on too.
i also have the shroud and doghouse cooler to upgrade from the nondoghouse. i need to buy the fan and and alternator plate or can i use the non doghouse parts?
anything else i should look into.
I spend way to much time on this site

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Re: small motor refresh

Post by sideshow » Fri Sep 15, 2017 8:20 pm

Head stud lengths differ between single/dual but backing plates remain the same. You maybe required to run the wider fan depending on the shroud (the oil cooler duct varies) but normally you can get by with the narrow fan at the expense of reduced air flow. It works but is considered a hack.

Your exhaust stud depends on your ability to either remove it and leave 8mm threads or create new 10mm threads (common step stud) or time sert the stripped hole.
Yeah some may call it overkill, but you can't have too much overkill.

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Re: small motor refresh

Post by Marc » Wed Sep 20, 2017 12:55 pm

What year is the case? If it's `70 up (B6 or AE/AK/A-whatever) it'll have the large-size oil passages which are compatible with the doghouse cooler using stock 021 117 051A seals, but if it's a small-passage case you'll need to run "conversion" seals to adapt. They come 2 to a kit, P/N 111 198 029.

Singleport coolers use 6mm hardware while the doghouse cooler adapter has 8mm - if your case is still 6mm you'll need to drill out the two "ears" and replace the 6mm stud in the top of the case...that's the potential problem area, if that stud breaks off it'll ruin your day. It doesn't have to be 8mm, but it does at least need to be longer to make it through the flange of the adapter.

In addition to the shroud and cooler you'll also need the two pieces of ductwork which route the spent hot air from the cooler out of the engine compartment. The "doghouse" style firewall sheetmetal has a window in it for the duct to poke through; you could just cut that out yourself. There are a several rubber seals which are often missing; just use RTV to fill the gaps where necessary to prevent the hot air from being drawn back into the cooling fan. ... -2.jpg&f=1 ... _w250.jpeg

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Re: small motor refresh

Post by Ol'fogasaurus » Wed Sep 20, 2017 2:26 pm

This is how to remove a steel stud in an AL piece.

If it is stud is a flush break (usually this is what happens) in the head then you have to make sure the stud is flat on the top then mark the center of the stud with a punch then, using progressively larger diameter bits, you get the hole in the stud large enough to where you can use an easy-out. Lube/candle wax is also used.

Make sure you do not get close enough to the threads in the head so you do mess the whole thing up. Also, make sure your are drilling parallel to the stud. Patience and being observant is the watch word.

I am sure that there are other ways so do a search on stud/bolt removal which is what I did.

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