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Smog head 1275 question

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hap having replaced my plugs with brass and seeing your comment, how much torque would you need to form a seal. it would seem to be that normal hand tight with an additional pull would be sufficient.
 
Replace the brass with steel now, and you'll not round out the Allen heads the next time you want 'em out. Brass is too soft, and Hap said it: YOU may be the next guy to work on it.
 
but the brass are sooo pretty! /ubbthreads/images/graemlins/smile.gif since the engine is freshly rebuilt, now would be the time to do it right .. thanks
 
Go get some stainless ones! It's softer than steel, but won't round out as easily as brass and they'll look just as nice! /ubbthreads/images/graemlins/wink.gif
 
Thanks all for the info and suggestions. I followed John-Peter's eBay link and bought a set of those plugs. I'm in the boonies here, so no good fastener shops close by. I like the look of those set screws, should blend in nicely. Now just need to get cracking and get that motor pulled.

Was a good eBay day today. Also won a copy of the Sunnen book that Hap recommended. It's out of print, so it was a nice score.
 
have to check but i believe the only ones i've seen on ebay have been brass ... i'll have to find a source
 
I didn’t see it posted yet so here it is - the threads are 7/16-20. I use the shortest available.
 
The threads are common 7/16-20 and I use a 1/2" long set screw for mine- work great.
Bill
 
Good score Drew, that book is great reference book, it basically tells you what you need to know to be able to walk in the machine shop and have a good idea on what you need and what to ask for and a good understanding of what the machinist is doing, it's also basically a owner manual for almost every piece of equipment Sunnen makes. So the time someone ask what sizing a bid end of a connecting rod means, you will know exactly.
 
Yessir, Hap. I either use taper point steel set screws, (7/16" x 20) or #4 SAE or AN steel plugs. The plugs have a hex head on them, which may be better for later removal. I also drive out the tubes from the chamber side, even though they don't intrude into the chamber that much.
Jeff
 
Hap I like that new avatar....can you post a larger photo?
 
I have always whacked 'em out too, as I figger they'd disturb flow a bit (can't be much at low end, tho), especially at higher RPM. Always wondered at the effect on flow of the hole left behind, too. Never did a comparative bench test. You guys ever?
 
Not me. I would imagine the little hole left behind may create some turbulence, but whether or not it would be quantifiable is questionable.
Jeff
 
Just curious. Didn't know if the hole was worth tryin' to plug and contour, or be more trouble than it's worth... I think we both came to the same decision: "It don't amount to a hill o' beans."
 
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