Port floor filling

Who can get inside the small Norton ports to weld up the floor? Space in tight and most welders can't accomplish it. Need to weld the end of a half round tube near the intake and exhaust seats for a porting project. Two recommended welders have failed so far.

See how much the floor needs to be raised in the photos below.

Intake


Exhaust


The outside ends are no problem:







The ends near the seats are the problem. The welds shown below fall short and are unsatisfactory - they need rewelding before I can machine new seat recesses and reshape the ports.

You must ask around for one of sandy kosmans former Tig weldors who i think could tackle such a job, as his work was back then next to magic, if he still is around and does weld.
Or else there used to be years ago a guy in San Jose who used to also do work on dragster frames afair and went by the name of Puccio.
That would be my bet for guys that I used to know.
To my knowledge rob north is living back in the UK again but that's just from hear-say.

Kind regards
Christian

Just asking but , has anyone used super epoxy's that could stay in the floor of the port. Just to alloy you to recontour, not keep a guide in place Sorry I have so may questions

JB weld/similar products is used for contouring intake manifold runners on a regular basis.

I would have thought laser welding would be the best bet. You don’t need to ‘get in there’… so long as you can point the beam at the area, it can be welded.

Imho one can TIG weld it as long as one is an experienced Tig weldor with a certain experience and theoretical knowledge as well as equipment (personally I'm inclined to think that such a job would be a lot easier with a modern inverter).

Kind regards

Christian

If you could answer the question, 'how did Mez weld D ports?' you might have your answer!

Happy if you can tell me I'm worrying about nothing here....

What I see is a method that puts aluminium pieces, probably made of slightly different alloy to both the head and the welding rod (if used).

And a design approach that leaves an air gap between the inserted piece and the original material.

Isn't that going to promote distortion, at least whilst welding, and possibly whilst running?

The problem is finding someone who can actually get in there and lay down a bead. It can be done - but by who (in the US)?

Its already been welded at both ends and heated to 400 deg befor and after welding with no visible distortion.

I just need to fill the rough areas near the seats.

Next time through I'll avoid this whole problem by drilling through the bottom an inch from the seat and welding the shoe there.

As mentioned previously I'm convinced that there would be still some capable tig fellas in the bay area or let's say eg the long beach surroundings
Jim why don't you call the guys at ex Jerry branch now mc Keefe porting, basically that's what mckeefe has been specialized in.

Kind regards
Christian

Ps: if using correct modern inverter techniques one does not need imho anymore to preheat with the proper machine settings.

Even with my Miller inverter tig, I find it helpful to preheat massive aluminum parts. I repaired Bonny cases and found preheat helped; a heavy Norton head would need it more. 300 amps focused on a small area can really induce some stresses.
Jaydee

I've never had JBweld fail in an inlet port when it's done right. The material is different and sands different but it's generally just on the floor. When it's part hardened you can push it into better shape.

I use a cutter and rough and clean the alloy surface.

I've been reverse filling a big port and it allows easy experimenting with shape. These little 34mm ports with 42mm valves flow extremely well, or at least make a BSA very responsive and fast. The one I'm back filling is for the same 34mm carb and manifold but expands for a 44.5mm valve. Surprisingly that pulls around 20cfm extra through that carb. About 70% more than through a stock head and carb. Not sure what that will do. I know what the 34carb 42mm valve will do, 10 races 8 wins and a 2nd. Taking 4.4seconds off a P3 lap record.

These all have raised floors using JBweld. Where it's not good on it's own on the BSA is breaking through into the pushrod tunnel I'd like that welded because the same material would be easier to get smooth, but have tried and lack the skill. Filling a hole there with just JB has it crack, just a hairline but it sucks oil. So what I've done is shape a thin piece of alloy to cover the hole and then some, and glue it on with JBweld and it doesn't fail. Only Thunderbolt heads or extremely big ports go through there. These little ones do not.

This shows really well the change from round to oval of the 34mm port. It's a bit wonkey in the floor and places but it flows good and I get scared of loosing flow fiddling with it.



What the profile looks like.




This is Lightning on the left Thunderbolt on the right.

This isn't a very big port but it's very effective. Roughly comparing flow through the 34mm carb to the stock Amal and port it's the std 105cfm to 160 and 180, but though the big valve version must have a higher through the carb and port speed, I have no idea if it will be better on an engine. It's for an 80x74 engine rather than stock bore on a 74 or 84mm stroke engine.

jseng1 said:

Who can get inside the small Norton ports to weld up the floor? Space in tight and most welders can't accomplish it. Need to weld the end of a half round tube near the intake and exhaust seats for a porting project. Two recommended welders have failed so far.

See how much the floor needs to be raised in the photos below.

Intake

Exhaust

The outside ends are no problem:

The ends near the seats are the problem. The welds shown below fall short and are unsatisfactory - they need rewelding before I can machine new seat recesses and reshape the ports.

Click to expand...

Someone with good eyes and a steady hand...