What are the stock fuel rails made of?

[BULL]

...or wife allows...

 

[Speedy!]

My old car had a front and rear crossover to the fuel rails that came with the Magnuson supercharger. At some point they stopped doing the front crossover. It'd be a study in fluid dynamics but I'd be curious what if any difference there is. Thoughts at the time was that 58psi of fuel pressure was 58psi whether it was stubbed at each end of the system, or in a circle. Either way can't hurt I reckon.

 

[2fast4u]

I believe as you guys do that the front added crossover will help to keep balanced flow in the system. I use a similar approach to air systems in shop when designing...balances pressure AND keeps flow EVEN.

 

[16GoManGoHC2]

My old car had a front and rear crossover to the fuel rails that came with the Magnuson supercharger. At some point they stopped doing the front crossover. It'd be a study in fluid dynamics but I'd be curious what if any difference there is. Thoughts at the time was that 58psi of fuel pressure was 58psi whether it was stubbed at each end of the system, or in a circle. Either way can't hurt I reckon.

I water my lawn a lot in the summer with sprinklers and what I could say is if I have three or four on the same hose and two hoses of them off a Y splitter off the same facet the first two on each hose put a lot more water higher in the air than the other ones as you go down stream from them and the last one of the bunch is putting the water up in the air the shortest distance and you could see the stagger from the first to the fourth Each one being a little lower than the first. I look at these fuel injectors as being fed the same way

 

[16GoManGoHC2]

Weld on adapters came in today, rethinking how to do this. The one cap is very close to the injector bung which are spot welded in place then what looks like brazed in place, caps too. One would have to be real careful to not get the tube too hot. Have to think about this one a bit. Bung weld on steps are .500 and .744, tube ID is about .710. It’s either .750 OD .020” wall tube or 18mm ID x 19 mm OD tube, hard to tell exactly as it’s not perfectly round and no way to directly measure wall thickness without a cap off. The weld on fitting can be turned down in a lathe to make a press fit cylinder to press into the tube ID then TIG or braze in place.

 

[Hpindy]

Weld on adapters came in today, rethinking how to do this. The one cap is very close to the injector bung which are spot welded in place then what looks like brazed in place, caps too. One would have to be real careful to not get the tube too hot. Have to think about this one a bit. Bung weld on steps are .500 and .744, tube ID is about .710. It’s either .750 OD .020” wall tube or 18mm ID x 19 mm OD tube, hard to tell exactly as it’s not perfectly round and no way to directly measure wall thickness without a cap off. The weld on fitting can be turned down in a lathe to make a press fit cylinder to press into the tube ID then TIG or braze in place.
View attachment 40064

What about machining the end off the cap gently ? ( fly cut , grind , whittle , etc)

Sent from my BBF100-2 using Tapatalk

 

[BULL]

Weld on adapters came in today, rethinking how to do this. The one cap is very close to the injector bung which are spot welded in place then what looks like brazed in place, caps too. One would have to be real careful to not get the tube too hot. Have to think about this one a bit. Bung weld on steps are .500 and .744, tube ID is about .710. It’s either .750 OD .020” wall tube or 18mm ID x 19 mm OD tube, hard to tell exactly as it’s not perfectly round and no way to directly measure wall thickness without a cap off. The weld on fitting can be turned down in a lathe to make a press fit cylinder to press into the tube ID then TIG or braze in place.
View attachment 40064

Tight working conditions for sure, but at least conceptually, and with TWO people, wrap the injector boss with a wet rag and have the second person specifically, and in a very isolated way, feed fresh cooling water to the rag to keep it cool...


Yes, way easier said than done...

 

[2fast4u]

I prefer to use a chunk of aluminum to heat sink, mill a groove in one side and sandwich it as close to weld area as possible...it draws heat quicker and dissipates it before it can affect surrounding area.

 

[16GoManGoHC2]

Tight working conditions for sure, but at least conceptually, and with TWO people, wrap the injector boss with a wet rag and have the second person specifically, and in a very isolated way, feed fresh cooling water to the rag to keep it cool...


Yes, way easier said than done...

Familiar with the process, done allot of copper sweat joints long ago. Planning on doing something of this sort around the injector bung along with freeze spray which is VERY effective. THANKS for the tip though, any and all are always appreciated 👍

 

[BULL]

Ha!

The other thing the second person could do is act as a rotary table as you work your way around the circumference...

 

[Speedy!]

My stuff's all here as well.

<rant>I prob will avoid McMaster in the future. They didn't accept Discover as payment (a pet peeve for me) didn't tell me what I was going to ultimately be charged, and no receipt in the box with the cap. I finally had to look at my account and see they charged me $16.25 for the $7.20 cap, so I assume the shipping was more than the part. My limit was $20 so I'll keep it but that's ridiculous and that put it in a massive box to boot. Coulda just dropped it in a padded envelope.</rant>

I'm gonna get my crew chief to do the welding on this. He says he plans to TIG weld it. He's a master welder and what he does for a living so I'll let him sort that out.

I'll probably start modding the fuel rail today starting with buzzing off the cap with an air saw.

Don't forget to account for how close the fuel rail is to the supercharger. The bung is a bit thicker so you'll either have to offset it to the outside 2mm or plan on shaving down the bung so it clears.

 

[16GoManGoHC2]

My stuff's all here as well.

<rant>I prob will avoid McMaster in the future. They didn't accept Discover as payment (a pet peeve for me) didn't tell me what I was going to ultimately be charged, and no receipt in the box with the cap. I finally had to look at my account and see they charged me $16.25 for the $7.20 cap, so I assume the shipping was more than the part. My limit was $20 so I'll keep it but that's ridiculous and that put it in a massive box to boot. Coulda just dropped it in a padded envelope.</rant>

I'm gonna get my crew chief to do the welding on this. He says he plans to TIG weld it. He's a master welder and what he does for a living so I'll let him sort that out.

I'll probably start modding the fuel rail today starting with buzzing off the cap with an air saw.

Don't forget to account for how close the fuel rail is to the supercharger. The bung is a bit thicker so you'll either have to offset it to the outside 2mm or plan on shaving down the bung so it clears.

VERY interested how you make out. It looks like the parts are soldered on after spot welding with a copper based solder?? TIG is going to get the fuel rail tube pretty hot but no doubt be the strongest joining. I’m concerned about the solder migrating from injector bung closest to where the welding is going to occur. I’m looking into SS solders currently. I’ll hold off cutting anything apart at the moment. Once you get the cap off of you would please measure the wall thickness and avg ID of the fuel rail please.

 

[Speedy!]

I hadn't thought about solder, but I'll let crew chief figure out how to get the bung attached. He said TIG, but I don't know he thought about any other solder being used on the rail. I'm sure they did that for leak prevention.

 

[Speedy!]

Quick update, bung is welded on. Crew Chief said to leave the cap to give more area to weld to and he'd regulate the heat to make sure it stayed put. Everything went fine and no issues with cap or close injector port having any problems.

However, he said the rails are either an odd stainless or have a coating on them as he had some trouble getting weld to stick. Stuck to the bung no problem, but would want to roll off the rail. He tried different heat settings and that didn't seem to make much difference. In the end he got it done, I'm not 100% sure how. Said he used stainless steel TIG rod as well as a tungsten carbide (I think that's what he said) which sticks to anything and still had to work with it to get it done.

I'm meeting up with him this weekend to pick it up, I'll pressure test, and hope all's good. He said he had to use a grinder to clean it up a bit which bothered him, but it's not visible anyway so I told him not to worry about that.

Something to be aware of if you're getting ready to weld them up.

 

[Magnified]

Stellantis won't divulge the build specs for the fuel rails?

 

[16GoManGoHC2]

Quick update, bung is welded on. Crew Chief said to leave the cap to give more area to weld to and he'd regulate the heat to make sure it stayed put. Everything went fine and no issues with cap or close injector port having any problems.

However, he said the rails are either an odd stainless or have a coating on them as he had some trouble getting weld to stick. Stuck to the bung no problem, but would want to roll off the rail. He tried different heat settings and that didn't seem to make much difference. In the end he got it done, I'm not 100% sure how. Said he used stainless steel TIG rod as well as a tungsten carbide (I think that's what he said) which sticks to anything and still had to work with it to get it done.

I'm meeting up with him this weekend to pick it up, I'll pressure test, and hope all's good. He said he had to use a grinder to clean it up a bit which bothered him, but it's not visible anyway so I told him not to worry about that.

Something to be aware of if you're getting ready to weld them up.

Yea, I’ve been mixed on doing this, I don’t switch fuels often, connecting the rails together up front be more of a reason to do this for me. I’m going to try it on a spare rail first, thought of silver soldering it to the cap verse welding. Please post pictures once you have in hand

 

[16GoManGoHC2]

My custom designed piston, quench area matches the head chamber instead of round dish dead heading into the flat areas of the head, be good for extra HP and Tq. They will be hard anodized in the ring areas and crown, then crown coated with a reflective heat barrier, skirt moly coated, entire piston sides then over coated with a cylinder fit material to make them quiet, DLC coated .225” wall H13 tool steel pins, 1.2 1.2 2.0 mm Total Seal rings, .310” top of ring groove to top of crown, be good for 225 hp per cylinder their engineering says. Unfortunately 8 weeks out

 

[Speedy!]

Quick update, so strike one on welding the bung on. During testing with compressed air we found some pin holes, so gonna try again with a different filler rod and hope for the best.

Also, Micah at OST gave me some tips, you need to maintain a decent amount of fuel pressure in the system to get the passenger side tank to drain, so keep that in mind when drilling the hole in the cap, or put a restrictor in the drain hose.

 

[TNREDEYE]

Quick update, so strike one on welding the bung on. During testing with compressed air we found some pin holes, so gonna try again with a different filler rod and hope for the best.

Also, Micah at OST gave me some tips, you need to maintain a decent amount of fuel pressure in the system to get the passenger side tank to drain, so keep that in mind when drilling the hole in the cap, or put a restrictor in the drain hose.

I'm guessing the cap is too thin to just drill and tap? Maybe weld a small plate to it and then drill and tap through both?

 

[TXRedeye]

Nice thing on the Redeye, there's already a AN4 schrader valve there. Got a hose from a fuel pressure tester pigtail with the AN4 and schrader depress on one connection, 1/4 NPT on the other, then a 3' hose with 1/4 NPT for draining. Have a relay switch to pop into the fuse block to control the on/off. Pumps out the fuel in about 5 mins for an easy change between 93 and HO and back at the track. I believe the fuel rail is interchangeable, change out with a redeye one is another option - of course could cost more.