Jim Fulmer

Yep I did make that change actually earlier this year at your request, it was requested at the beginning but the designers name was never mention till you said it and I did so with the 16cm housing in place and lost 250 degrees of EGT doing it, I went to the 18.5 for several reasons 1. It was free 2. The drive pressure was higher than 1to1 at 65 psi 3. Just to try it. I don't know much about a 24V that's for sure, but one thing I do know better than anyone....my truck, that about all I have to rely on as far as Twins, or the little ones. Now I'll see how the PDR40/Big Brother set works out in time.

Jim

Don M

Tim,

bolted shut is probably good on the wastegate. Again, this is all theory that needs to be or should be tested.

Cool on the oil analysis. Your blow-by must be minmal.

Jim,

Yes, of course you know your truck.. I know mine too and the thing is hurting for hard parts. :'(

With the success of the BB turbo and the B-1, I would bet the HX40 combo would work very well too. If you fellas dont slow down....Im never gonna catch up
Even the B-2 and the HX40 is proving well in Nates rig. Not sure how it is gonna like anything larger though.

Speaking of my truck...I got a few hours to play today between posts. I have not touched it since the Dyno Day. Man, I gotta tell ya....I must have been half asleep the last time I worked on it. Mistakes everywhere. I guess being up all night long and the following day is not too smart. Oh, I finally got a real air filter on it too

Don~

VinDiesel

Hi Guys, I might just jump in for a sec on what Proram said about exhaust size. I was talking a couple of months ago to a guy at Stan's Headers (Chris, maybe?).

Anyway, seems they've been doing a little dyno testing on twins (PSD, I think), and found that a 5" downpipe reduced to 4" actually lost power over a 4" all the way. Just something to think about.

Battering Ram

Tim, I can ship you the old 32cm housing if you want me to. It had slower lag but it will definantly slow down the 3B and flow better. It will save you from buying a 26cm right away. Let me know if theres anything I can do.

P.S. Looks like you have blown away your 500hp goal already .

John_P

Tim:

Glad to hear your twin turbo system is working good
for you!

You asked about how much boost O-rings would hold.
It is my understanding that with the 12mm studs and
the O-rings you are safe to about 75-80lbs. The 12mm
studs can be installed without any machine work, but
if you install the 14mm studs, the block has to be
machined. With 14mm studs and O-rings I would
think you would be good to around 90-100 lbs. of
boost. Send Doug Smith (Jetpilot) a P.M. and he
can give you some good info on this. He recently
had to replace his head gasket and I think it blew
due to high boost. He has the 12mm studs and
O-rings.

-------
John_P

joefarmer

I spoke with Doug at Enterprise Engines last week and he was telling me that they hadn't found an upper limit to the amount of boost that could be run with o-rings and standard head bolts. I asked him "So will you use head studs when you put in the cam and o-ring my head?" His answer was that they just use new headbolts and not studs. I did mention to Doug that my goal is 650hp and high boost twins. Is there evidence that head studs ARE required for high PSI twins supporting 650HP on straight #2?

brandon.

Don M

I think EE is correct. Standard head bolts are very good when TQ'd correctly. There are more reasons for this than just plain old clamp load.

Don~

dodgeman01

Man I wish I could win the lottery.
Sittingaroundlookingforahx40DM01

pro puller

[quote author=joefarmer link=board=7;threadid=22734;start=15#msg213329 date=1069651363]
I spoke with Doug at Enterprise Engines last week and he was telling me that they hadn't found an upper limit to the amount of boost that could be run with o-rings and standard head bolts. I asked him "So will you use head studs when you put in the cam and o-ring my head?" His answer was that they just use new headbolts and not studs. I did mention to Doug that my goal is 650hp and high boost twins. Is there evidence that head studs ARE required for high PSI twins supporting 650HP on straight #2?

brandon.
[/quote]This is what EEP told me also so that is what they did.Stock headbolts with the o ringed block & it hasnt blown yet.But then again i just started making some real boost thanks to Don ;D.Kurt.

joefarmer

Thanks to all for the info regarding the stock head bolts. It helps to have other people break stuff so I can learn cheaper. :

Hey Kurt, Did the DD cam help out that much? If it messes with timing, does it mess with the timing boxes (EZ's etc)? Have you tried it with those?

I figured that I may as well do the cam while the engine's apart for the head work, after all it is just money. : I know there was a discussion on cam's awhile back, but it didn't seem like any of them were far superior over any of the rest. So I'll just go with EEP's cam.

As for keeping this discussion on track, Tim, are you doing cam and valves when you do your orings? Or are you gonna try to keep it under 55 PSI and not do the head?

One more for ya, regarding DD's pulling clutch: how many HP do I need to seat it right? Or do I just need to hook up to the 'dozer trailer and pretend I'm Richard Petty? ;D ;D

brandon.

Timinva

Brandon, I am gonna o ring it soon probably get it ported also. Cam is gonna have to wait. I am running 65psi now and all is well so far but dont want to push my luck to far. Tim

John_P

It doesn't make sense to me how a stock Cummins headbolt
which calls for about a 90 ft. lb. torque (plus a quarter turn)
can hold better than an 12mm ARP Case Hardened Stud
which is torqued to 120 ft.lbs.? ??? IMO, when you start
getting over 60-65lbs of boost there are only two kinds
of stock headgaskets; "the ones that have blown and the
ones that are going to blow." That is right where my 96'
12 valve was at when I blew the stock headgasket at
around 125,000 miles. No problems since Scheid installed
the studs etc. and I now have a little over 225,000 miles.

Good luck!

-------
John_P

Don M

John,

Studs do have a place for certain. Quality studs from ARP is not like anyone else makes, but they are not always needed.

Stock head bolts prove to be very good if installed and TQ'd correctly.

Don~

pro puller

Brandon,
Its hard for me to tell if the EEP cam made a differance or not because i did the twins at the same time.I will tell you this with the hx40 & the ht3b the spool up is almost as good as my old standard housing b1 but the egts dropped about 500 degrees.Im sure most of that was due to the twins but some good had to come from the cam (i hope).My truck just made 580 horse & 1100 ft lbs of torque with Dons Mach 5 injector & this was only at 52 pounds of boost.The dyno i was on could not load the motor to make any boost.On the street it will easily hit 70 psi.I think if i could get that kind of boost on the dyno i would be well over 600.My old setup was a b1 with dons nozzles on nitrous & it made 600 horse & now it feels stronger with the twins on good ol #2.I also had hard time keeping the tires from smoking on the rollers.33 inch procomp x terrains arent the best dynoing tire.Hey Don i think maybe i will try those Mach 6 nozzles if ya got a set layin around .Kurt.

HOHN

Hi fellas. Hope you don't mind me asking questions here. The twins topics are somewhat new to me.

I am looking at a twins setup that still uses my stock HX35, albeit with a larger housing. I will be keeping it under 50 psi until I can get the head done.

What is the Big Brother turbo? Is this the B2? (big brother to b1)

How about a combo of the B2 with the HX35? I realize that the small turbos need big wastegates to avoid choking. Is there any waste on the primary?

I need to post a thread on twins theory. I have yet to see one where all the tech stuff on twins was hashed out in one thread.

Don, if the length of the flow path A (through the housing, turning the secondary's turbine) was the same as flow path B (bypass flow through WG on secondary), would the turbulence be reduced by a considerable amount?

I'd imagine this still doesn't do much for the temp (and therefore density) differences of the air in the two flow streams.

It's a pretty tough challenge to engineer a twins setup where all the flowstreams have no shearing forces or sharp bends that would induce turbulence.

BTW-- the fueling level for this twins setup would be a PMAX comp and Mach 4s-- not too hairy.

Justin