Stl94LT1

arnie

That would be 5(6)1 heads. Regardless, that has NOTHING to do with thin wall castings. The thin wall pertains to casting thickness adjacent to the water jacket. This issue is with the location of the exhaust bolt hole. That is not a variable with ANY set of OEM heads.

BTW, you are not "lubing" anything. The reference is to 'sealing'.

As far as having any mismatch of the port wall with the opening of the exhaust extractor used, if one were to look closely at the pic, the wall curves back in toward the center of the port after breaking into threaded hole. With this reduction of port width at the flange surface, there may not be any mismatch to be concerned with. Check opening with the manifold/extractor used. This isn't brain surgery.

F6

I think there are plenty us who are having such problems with the port being not properly ported. I think instead of doing one side first and then the other, both sides are done at the same time and so the porter doesn't really know how much he took off of one side.
This is an intake port and Lloyd just casually saying, just put some sealant under the bolt head and it will be ok, doesn't satisfy me. If I wouldn't live so far away from him I would sent the head back. There are a lot of other things I could criticize looking at these heads.

You always get what you pay for.

arnie

It's very possible that is the cause as the 'reference' surface has been altered, though there
is another (but adds labor time/expense to job) way of referencing before porting begins.It wouldn't me either. If I'm not expecting to spend additional time/money to repair holes I wouldn't tolerate them either. That implies the head(s) go back with the understanding it is
at porter's expense for possibly an exchange for a different set. But is not our decision is it? That is up to the guy paying the bill.
Somethimes more! In this case customer got break through surfaces/holes at no extra charge.

gunter96ws6

i know lloyd personally,hes an lt1 wizard. if he says its fine, trust me its fine.

wrd1972

Sorry I fat fingered my response and was far too vaugue. My vaugue reply should have stated that the 561 heads are more prone to breaches into places one would rather not go whether it be this exhaust bolt hole, stud hole or water jacket.

jwindh1

Alright guys, I developed a fix for this and will post pics later. My grandfather works for a company called Belzona. They make industrial protective coatings and repair composites. He came over and applied Belzona 1111 "Super Metal", it is a machinable, rebuilding grade product. In it's simplest form, it's a super high performance JB Weld. I used to do side work while I was in college applying Belzona products. I have seen it used to temporarily repair an actual battleship hull all the way down to a dozer manifold. That "temporary" repair on the battleship has been on there for over 10 years now.

Anyway, we applied it by putting some into the bolt hole, coating the bolt with a release agent and then screwed the bolt into the hole. When we did this it forced the product through the hole in the port wall and I then wiped it smooth to match the contour of the port. It's sandable, so I will do a little touch-up sanding to finish it out.

I know that this process was not necessary, but I was not comfortable with the thought of an open hole in my exhaust port. Besides, this fix only cost me 30 minutes.

Injuneer

The Belzona website product data sheets are a little skimpy with reference to the maximum reocmmended operating temperature. Is it good for up to 1,300*F?

96SSIndeed

We use Belzona at the chemical plant i work at. From personal experience he could use it on any part of the car and never have a problem

jwindh1

96SSIndeed, What plant do you work at?

96SSIndeed

Used to work at an Oxychem. About to start back in a week or 2

STOCKTA

Yes belzona is the master of reshaping ports for higher velocity in ATV and 2stroke drag engines I have built. I have honsetly cut the entire port out of banshee's and many 125's and also a couple SBC heads and rebuilt the entire port cross section with belzona then re-ported over the belzona.
Check out some of the belzona tricks I have used to raise this LT1 intake port roof without having my buddy weld it.



I have also ported and used belzona in 80% nitromethane burning drag dirtbikes and many many many 50,000rpm nitro rc cars, that epoxy WILL NOT BURN OUT!!!!!!!! It has a great expansion and cooling rate that is very close to aluminum and I have litteraly baked the stuff with a torch trying to make it fail. It only gets stronger the longer it cures. I have also used it to fill bolt holes and redrill and tap the belzona area to fix major stripped holes and cracked spots in intakes. Also have fixed many gasket area's on intake gasket flange where people have gotten to aggressive with the die grinder.

So defintly take your grandpa's advice and use this stuff, I bet he knows the exact ratio of the two epoxy's that need mixed for different tensile strength. I used to mix up a different ratio's of it to fix different kinds of parts, like a-arm's and hubs just to get home

wrd1972

I will never use Billy Mays super mighty putty ever again.

STOCKTA

lol!!!!!

bombebomb

It seems that you will be fine, but if I just paid $1300 for a head port, if I got one back with a hole in it I would not be happy.