AlanF

I am thinking of building up a set of compound turbos. I would like to fabricate a weld el manifold as a start. Where do you think I would be able to find a done for 24valve cylinder head? I understand that it is not entirely uncommon to get cracks in the head, would a local Cummins outfit likely have some bagged heads? As far as twins go, I will need to do it as cheaply as possible so stock turbo and a S400 or BHt3b will be my route.
Alan

renopker

why do you need one?you have one already bolted to the motor.Id use the stock ex manifold save the work.

Tate

I think he wants it so he doesn't have to take the truck off the road to build them.

PDR and Peak aren't far from you, call them and see what they have. 12v head will work just as well for building the twins, although the port openings are different shape if you are building a manifold.

AlanF

I will give them a call to see if they have anything I can use. I would definatley like to have the head so I can build the set off the truck. I know the stock exhaust manifold will work, but crazy me I have always wanted to build a header!?
As far as making a nice serviceable well matched twin set with the stock turbo, does anyone have some advice for me? Should I try to source a 14cm exhaust housing? Would I be better off getting a non wg housing and plumbing an external wg between the turbo and the manifold collector? Does the stock wg on the 12cm housing bypass enough exhaust or does it need modifying?
Which turbo for the primary? S400 (B1 ?) or an ht3b with the 26cm exhaust housing? I have read that the plumbing is a little cleaner with the S400 based turbo. A little experienced advice on these issues would be very much appreciated.
Thanks
Alan

Mike Holmen

I have a spare head and exhaust manifold available. You don't need that to build twins. Most of it you can build off the truck and just do the final welding once its in place. I originally thought the same way as you, but if you want everything to fit right/nicely in and on you're truck, you better build it on you're truck. You should buy an ATS manifold as well. The stock exhaust manifold is prone to crack with all of the extra weight. If you had a complete motor, that's the way to build twins and no I don't have a cracked block but Tate does.

Dr. Evil

Oh really????


Let me guess a 53???

Mike Holmen

Ya he bought one cheap for parts. I'm not trying to start any rumors. You want mine, its an old PDR stage 2 head that has a bad crack in #2 and #4 cylinder. You'll get it for a faction of what I paid for it.

Its not even worth the shipping to vancouver. This is my second head that I've had to scrap due to cracks.

Hardest part of building twins is the primary support bracket and the 5in down pipe. Other than that it's smooth sailing. Go with a S400 or garrett style primary, they go in the easiest. The 3B is a pain as you need a few more bends than other types. The hot downpipe is best welded up on the truck, so else you have stuff that doesn't line up right and will have difficulty sealing up as the turbine outlet to inlet surfaces. They will not meet up and are all ***** to each other. Kinda like buying a custom suit thats fitted at the store. The best way is to park the truck for two or three weeks and just adjust until its perfect. The next issue is the discharge off the secondary turbo to the intercooler. The little misc parts will drive you crazy like drain lines and supply lines.

AlanF

Thanks for the reply's. Mike do you know of a good (affordable) place to source the S400 North of the border? Or should I just order one from HTT or other US vender. I don't imagine there is much room for the exhaust downpipe from the primary, so I see why you recommend to weld it in place. As far as a parts list, does this sound about right? I will need a backplate for the HX35 and a T-4 flange to make up the hot pipe. Sch 40 pipe 3" is the correct size I think. I will need a weld on compressor outlet flange for the S400 with v band clamp and silicone hose and flat clamp to connect to the HX35 inlet. Is it worth doing an external waste gate or just use my stock 12cm with internal gate? Looks like oil feed lines are readily available from Vulcan. I have the '99 auto, do I need the straight or angled oil return bung? Source automotive sells both. What about the trans cooler, apparently there needs to be some modifications there?
Alan

Mike Holmen

Yup I do know of a good place to buy turbos. Don't use sch 40, too thick and you have to use tons of heat to get the welding to stick. I used exhaust pipe and 3in. The brace takes all of the weight of the primary turbo, the thicker metal actually is too much and things just wiggle loose. The pipe has to give a little wiggling. How much stuff do you have? Were are you located? Auto source does sell little stuff like flanges, and such. I can get stuff water jetted locally. They do pretty good work. What you doing with the wastegate?

Mike Holmen

The heat exchanger has to moved to front of the truck. You'll have to run new lines for the tranny. I dumped the stock cooler and went with a 1/2in/out B&M fan tranny cooler. The stocker drop the line pressure to much and restricts flow. 5in elbow are the trickest part of the build. If you can find them you're away. Its a fun project thats pretty easy, just dont give up. I just went and did it. It took about a dozen beer, but it works. I can light the tires up from a dead stop and burn them for about 20ft, thats without using the brakes. Of course at sea level that easy stuff, but I live a 3700 ft. There is less air here than down there.

AlanF

How thick did you make your flanges? I would think that welding 16ga to 1/2 plate would be a little tricky! I haven't looked for 5" elbows, are they hard to find? I have a 4" exhaust currently, do you make a 5" down pipe and then transition to 4"? Do I need to go 5" out of the turbine outlet or is that the only way.
I am a shop teacher in North Vancouver, so I am "relatively" well equipped. I have a Miller 251, a synchrowave 200, vertical bandsaw, bead roller and slip roll as well. I have a baby 13" lathe, but unfortunately no milling machine. I have done a fair bit of welding and fabricating, so I figure I should be able to pull off a decent job.
As far as wastegate, am not sure. If the stocker works.... fine. If it doesn't, than I will have to come up with something else. Looks like it would be easy to make an adapter to go between the manifold and the turbo and use an external.Not sure if there is enough room, it would use up a couple inches I would think.
Alan

Mike Holmen

I would get the turbine inlet/outlet flanges machined somewhere. but.. Remove the exhaust plate, there's a gasket under the plate. You can use it as a template for a flange thick enough and wide enough so you can bolt it to the turbine housing and have enough meat. A plasma torch works nice so does a blow torch for that one. My plate out of mild 1/2 plate steel. A cutting table of either a waterjet or plasma style is the way to go but...trust me.

Talk to the Hiway truck shops to find the 5in stuff. I haven't tried that part yet, but I heard that works. I would also do some pressure testing on you're new welding job. Source Automotive had a big sale on the stuff recently. Its kinda like kid in a candy store. You might really only save $1 to 1.5k of a set of new BD twins.
I just do it cause I get bored at home and I like to tweak. Once you get everything cut up, I can help you with the wastegate prep. You could also do searches on wastegate.

Oil lines and oil fittings are next. Thats pretty easy, just find a hydraulic shop.

Tate

Might be a 53, never looked. Was in a front end wreck and broke a piece off the block where the lower rad hose connection bolts up. Side of the block is still good. If he were closer, he could borrow it, but I don't want to lose it until after my ford gets a transplant.

ScottGregory

I've got a 53 block i'd let go cheap. No it is not cracked.