Engine/Transmission (1994 - 1998) EGT's Still high after twins

[JHastings]

Well I have my twins in and my egt's are still high. With the fuel that I have, I only put down 298 with my stock 35 and at 1800+*. That seems a bit high to me. Now that I have my twins on, egt's are still up around 1500-1600 on a hill, of course I don't keep them there for anything but a second or two. I have hit 52 psi so far. Cruising egt's with a my stock trailer are 900-1000* at 70 mph and about 18psi. I guess I was looking for better results than this on a truck that is maybe putting down 350hp. Maybe my wastegate is all screwed up. I worked pretty hard on modding the stock 12 cm housing by enlarging the wg to 1" instead of 3/4" that it was before. Lathed a new flapper and then milled out the center divider to gate all 6 cylinders too. Spool up is not all that great. What do I do? How do I set my 35 gate correctly? Should I put back on my stock 12 housing? Look into an external wastegate? If I did this can a somehow weld it onto the 35 exhaust housing or do I have to make a new piece between the ex. manifold and 35 exhaust housing? I will say that the pickup is a lot faster, but thats not really was I was going for. Are my numbers way off or do they seem about right? Bottom turbo is a BHT3B/26 with out a center divider.

Thanks and sorry for the long question.

Jamie

 

[GDMRTN]

I think you need a 22 housing on the big charger. That'll change things. Faster spool, lower temps. I have a 22 an love it.

 

[cahammer]

when was the last time you checked your timeing?

 

[CogginsP]

when was the last time you checked your timeing?

thats what i was going to say... sounds like its time to advance it a few degrees

 

[Forrest Nearing]

do you have a boost gauge on the bottom turbo?

 

[JHastings]

I don't have a boost gauge on the bottom turbo. If I but on in, do I put it on the cold pipe? My timing tools are loaned out at the time, but I will start there as soon as they come back to me.

Jamie

 

[thekidfan]

Check for boost leaks then as mentioned check timing and bottom charger output! You can either drill and tap the 3b or the cold pipe!

You should be having a hard time seeing 1200 at the power level you say your at even with a trailer. Something is up tuning will help a ton but it sounds like you have some "big issue" as well!

I have a 23, I found a 22 after I bought it and thats what I run! If you decide you need quicker spool-up lmk cause it's for sale! 22's are great but very hard to find for a decent price. Good luck to ya! Jeff

 

[12V Ford]

Not to steal the show, but with boost gauges on both turbos, what should the turbos be putting out at max boost, moderate boost, ect. too help Jhastings and me out.



For me, max boost is 55psi, 28 psi ht3b, and 27 psi hx35 (no blow off)

Moderate boost 20psi, 6 psi ht3b, and 14 psi hx35

 

[JHastings]

OK so something is definitely wrong. Can timing change my egt's that much? Here is a bit more data from today. Loaded, I was hitting 1500* at 52 psi and drive pressures never exceeded boost. I will put a boost gauge in by drilling and tapping the 3b at its outlet. How can you tell what the 35 is putting out? If drilled and tapped at the same place, won't you be seeing the boost from the 35 as well as the 3b behind it? Also anybody have a lift spec for an 841 pump? I'll do all this stuff first then look into a smaller housing if needed. Thanks for all the help.

Jamie

 

[thekidfan]

OK so something is definitely wrong. Can timing change my egt's that much? Here is a bit more data from today. Loaded, I was hitting 1500* at 52 psi and drive pressures never exceeded boost. I will put a boost gauge in by drilling and tapping the 3b at its outlet. How can you tell what the 35 is putting out? If drilled and tapped at the same place, won't you be seeing the boost from the 35 as well as the 3b behind it? Also anybody have a lift spec for an 841 pump? I'll do all this stuff first then look into a smaller housing if needed. Thanks for all the help.



Jamie

Couple more things I won't ever dyno on a dynojet again because of the false readings (about 200 rwhp low) not saying thats your issue but you may be higher then you think!

What do you mean by "loaded" with or without trailer what's the lbs. flat ground or up-hill?

You have a 10 plate and 191's, any injectors?

Boost and D. P. sound good, are you O-ringed as well as studded?

piersdiesel.com (his old site) has pump lift/timing specs listed.

 

[JHastings]

Yep. Studs, O-rings, Copper gasket. I dunno. I doubt that I am over 350. I can't pull on the new stock CR's that much. Loaded is about 7K today. Up 7% grades. No injectors, just the stock 215's. I'll start with checking the timing and go from there.

 

[JHastings]

I blew an the boot inbetween the 35 and the pipe that leads to the intercooler last night on my way home from the ranch yesterday. Only had my stock trailer and one horse going up a long hill. 40psi and then poof. Got me home though and replaced it with one from truck stop today that has wire around it. Held 52psi. BTW one of my bolts holding my afc stripped out and oil going down the side of the motor. This would affect my egt's though would it? Have to tap it to something larger tomorrow. also going to change my drive pressure gauge to my 3b boost gauge as well to see If I can't figure this out.

Jamie

 

[Jim Fulmer]

Jamie, be dang careful when you tap that hole, it doesn't have to be very deep and if you drill really deep you will knock out the bottom into the Governor housing..... not good. You are better off to drill and tap the hole for the same size, and that is M6 x 1. 0 pitch.



Jim

 

[Partyat33]

I would still be looking for boost leaks. I had one and my EGT's were almost 1800. Fixed the leak and can't break 1500. I plugged the big turbo intake, plugged the pipe before the horn and put air in the cold pipe which was already tapped for a 1/8 NPT guage.



Dennis

 

[WDixon27]

when i found stripped bolts for my afc i looked at the holes and saw how deep they were and just went in with longer bolts to access the virgin threads below the stock bolt's reach, the next step id go with would be 6x100 helicoils

 

[JHastings]

Helicoils sounds like the way to go. What do I need to do to put them in and where can I get them. Napa, hardware store,... Can I reuse the M6 allen heads that I have or do I need smaller ones?

Also, I will try to put the compressor on the charge air system to see If I have any boos leaks. How did you plug the intake on the big turbo?



Jamie

 

[WDixon27]

with a helicoil you end up drilling the hole oversized and tapping it installing the insert which brings the size back to the original thread size and pitch, it's a good repair when done properly should be stronger then before, but before chancing tossing all of that aluminum spoil down into the pump or misdrilling a hole id try a longer bolt, dipstick the holes and see how deep you can go and try that, the threads will be 6mm x 1. 00 by however deep the holes are, just about any parts store should have or be able to get helicoils, i like helicoil brand (usually napa) best but off brands usually are ok, i am not a fan of timesert type threaded inserts, it's a ring of threads with a expandable part that swedges the insert in the hole

ps the helicoil kit should have everything you except a drill

 

[JHastings]

Good to know. Yep I checked the depth and my bolts reach to almost the bottom so there are no threads left. I think I am going to have top put helicoils in there and be done wit. I'll be very careful to not go deeper than what is already there. Thanks for all the help. Next, I'll check for boost leaks. I'm hoping thats it.

Jamie

 

[Don Tanklage]

i am not a fan of timesert's... .

they work ten times better than a helicoil

 

[JTroiano]

My question is if you have good boost a small leak is not going to make a huge difference but how much black smoke is still there when your temps are high? It is a sign to tell you if you have enough air/boost. I pulled 13k for the first time last night and I could'nt get over 1100. But my boost pressure was max 60-65 at times and 40 when driving nice and 20-30 cruising. I don't use a waste gate. My HX still has the valve for future use but it is clamped shut. If you have all the head stuff in place to run high boost I would clamp it shut and take it for a ride and do it in steps. No more that 80-90 psi, then you can mess with the gate if you are to high. I don't know what size housing is on my HT3B but it runs between 15-25 psi.



Now my transmission on the other hand was screaming for mercy!!



Jon T

503-519-5366