The cap material is a lot thicker, but not bulky, than the OEM caps, so I don't think it'll be too bad to weld them. I agree and would rather have gone with an interference fit w/ Lock Tite. It was an after thought on both of our parts when he was machining them.

My wife's friend's husband is like a surgeon when welding, so I hope he'll be able to do it. I still have to show him the project to see if he'd be interested. Now I've got to find out what his favorite kind of beer is.

 

Ask pops what alloy so you can tell him when he welds them so he can match the fill rod.

 

Unless there is something strange going on, likely choice for those is 6061-T6, and can be welded with either 4043 or 5356. If one was thinking of anodizing them, use the 5356 though. If you were in my neighbourhood I could have tigged them for you here at the house.

 

Actually, I was half joking about the liquid nitrigen. As usual, I probably should keep quiet about things I only sort of understand.

On the other hand, I was thinking that the locktite might fail or not bond correctly, based on vague memories of stories about locktite and aluminum. An interesting article on AL and locktite blue...

http://www.devcon.com/prodfiles/pdfs/fam_tds_350.pdf

Basically, for pure aluminum (not necessarily alloys), using an activator is recommended.

I forgot to mention -- those caps look really nice.

 

I watched a How It's Made show the other day and it featured Ferrari engines. They dip some parts into liquid nitrogen in order to effortlessly press fit them into the motor. It works great. I thought the same thing about Lock Tite not holding up before the project began, but had second thoughts after the machining. I'm pretty sure it won't hold as well as a continuous weld.

 

Thanks all. I hope to get these finished soon and installed for testing. I've been drenching my injectors with a penetrate in anticipation for swapping them out. I've got to buy a set of glow plugs and valve cover gaskets to complete the project. I'm contemplating viton tubing for the return lines, but actually like the cloth wrapped look.

I sent him an email asking that.

 

One of the machine shops I worked in we used liquid nitrogen for one particular job. It was a copper shaft that was pressed into a copper bar, roughly an inch in diameter. If I recall correctly, at room temp, the shaft was about .0015" larger than the hole. Procedure was to let the end of the shaft hang in liquid nitrogen for 20 minutes, then a 20 ton press was used to install it. If you stopped the press for any reason, the temperature change was such that it would lock together, and you could not get the press to go again.

It's common on sleeve/liner installations to sit them in a household freezer for a while first, then slip them in, they'll shrink enough to push in by hand.

 

liquid nitrogen has been used for many many years for interference fits, personally done it thousands of times.

I would have done them .0015-.002 interference fit, heated the cap, froze the nipple and slipped them together, with good machining they will become one piece for all intent and purposes.

I would also bore and ream the nipple hole in the cap to a depth less than the wall thickness of the cap, thus the nipple can only go in so far and leaving the inside of the cap as clean and smooth as possible.

Locktite and aluminum should not be used together if you ever want to take them apart, locktite penetrates the aluminum porosity and will destroy the components upon removal.

They do look nice.

-Enjoy
fh : )_~

 

It's reamed ~1/2 the wall thickness of the cap, thus the barb only can go in that far and the inside of the cap is clean and smooth. All parts have been reamed.

With my mechanical design experience (automated manufacturing machines), it is best to use a weld for this material and application. Yes, it's low pressure, but with the changing heat daily and continuous vibration on the motor, a weld is superior in every way. Even if I press fit the barbs, they would be welded after.

 

Awesome, I didn't see that stated anywhere.

Total Hogwash ...

-Enjoy
fh : )_~

 

 

I absolutely 100% retract my surgeon statement. He ****ing ruined all of the ****ing caps. ****.

 

that sucks mechelement.......... bet your dads gonna be heated huh? they looked so fing good too

 

Oh man that blows! Weld inside the nipples or just melt through the whole thing with too much power?

 

I haven't told him yet. I'll break the news to him tomorrow.

I have no idea what the guy did. My wife brought him the parts and watched him ruin all of them. It looks like he used a 1/8" diameter rod on the damn thing.

I think these require a micro TIG welding process instead of conventional. I'm exploring other options now.