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Discussion Starter #1 (Edited)
haha just couldn't help myself.

Maybe I will try and transfer some of the info from our conversation onto this forum.

But what a couple of us have going...and can chime in is a collaborative effort to get a couple of these things to the 400HP mark and make them reliable every other day drivers. Hopefully it can be done on #2 only but might have to cheat and use some drugs to get that extra umph.

Not doing anything to different than mentioned in the 350HP thread except for sure am going with twins, and going to use a snow control and nos system to crank out some really good numbers and keep the EGT's down. Also to help reliability going to use a copper head gasket with the 0-ringed head and arp studs. And if I can work it out a fluidampr.

In order to keep the cost down might not be doing the camshaft either...all depends on what it is going to cost. I know the snowcontrol is expensive but there are others out there that are a bit cheaper.

Would like to devise and overhead intercooler to help reduce boost pressure loss...but I think I'm going to have to leave that to someone who can cut into their hood...not going to be able to on my truck.
 

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3.9 400bhp

Hi, I have posted Q's on a 6BT site and was warned off a copper HG as it needs constant retorquing. I understand that a marine HG +20 thou with studs would probably be good for 50+ psi, I also asked about twins but no real knowledge came back apart from bottom turbo should be roughly twice the cfm of the top turbo so I was thinking HX30 top with HX40 bottom and as the HX40 flows about 2/3 of a HT3B it is probably in the right ballpark.

Gaza
 

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so are you using the stock lower end or have you rebuilt. Just curious if you are using any aftermarket parts(i.e. pistons,rods,bearings,) Im really considering having everything ceramic coated$$$$$$.:puke:
 

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The TDR guys came up with a pretty good head torquing technique that they say makes the head gaskets stronger/last longer.. Instead of the 90 ft/lbs then 1/4 turn that the manual asks for (which is a hell of a lot of torque, I used a 3' extension), simply 125 ft/lbs and that's it. Less torque actually! But the same bolt pattern.. Here is the torquing technique. This is a 6 cyl but it is the same minus two cyls of course...
 

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Discussion Starter #5
That is interesting. Have they proved anything with tests and can they explain why ????
 

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Discussion Starter #7
wow that is some intersting reading and all very common sense. haven't read the tech article...will have to save the 53 pages for later :)
 

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New to forum, first post, so don't kill me :). I have a 4bt and watchin you guys to storm the way for me :) I have a couple of 6bt's and comment on those...for what it is worth..

I've o-ring my head, arp studs and marine gasket. I made the mistake of going .020 over on the gasket, cause the shop could not remember if it was .009 or .011 milled. In either event, I should have used the .01 gasket at most..Have the heavy duty valve springs, and 4k gov kit. Yes, I can turn 5k, but limit it to 4,500 at MOST. Usually by 3k I'm out of it...

I blew my stock gasket with 170k miles on it doing over 42lbs of boost. I'm sure that the egts were not helping it either..Many, people in my 6bt group are pushing up to the 40-50 range on stock, and in the 80-100 range with duals. DO not fear the bottom end on these things :)

I'm currently still using a HX 35/14 w/4in with the fuel turned way low. I hit 42lbs and can hit 1500F with little effort, just with the afc working. I'm around 380-450hp.

This is with stock lower ends, no ceramic parts, etc...

I'm very interested in the turbos you will use and the pump work done. As a general rule of thumb, the 6BT makes about 9-11hp per lb of boost. I would expect that the 4BT would make a bit less, 6-8 hp/lb? Is that fair to say? So making around 35lbs(safe stock limt?) would make about 230 hp. At that rate, you would need about 60lbs of boost for 400hp? This would require, gasket/o-ring/studs...

I have yet to hear of STOCK readings (boost/egts) on these engines(would like to know). Maybe I'm thinking backwards? Maybe they will make MORE hp/boost than the 6BT? Please inform me :)

An HX-40, would NOT be able to supply the pressure that are needed for this, it is out of the map range. Like the HX-35, they can do apx 40lbs but don't like it much. I believe a set of duals will be needed for this pressure. Can the injector pump supply this much fuel? No insult, I know the P7100, not these pumps, yet :)

I look forward to what you guys do(so I can do it myself :) Thanks for the great site...Hope I didn't insult by refering to the 6bt, so much :)

Quadzilla(not the seller)/Wayne
 

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What Wayne said. Also it seems some fairly heavy head porting would really help if you're planning to press the limits. It's free power and acts to reduce some stresses rather than put more load on the engine.

I've heard [no supporting data] on other forums from some pretty knowledgeable folks that the Holset line of turbos though high quality and reliable are not near the top of the heap for serious performance. I won't make alternative suggestions but you might want to research that and see what else is out there. Might be a shorter way around the barn than dithering over a combo/hybrid setup.

Methanol injection can help, and so can propane or nitorus injection. With methanol you don't have to hassle with DOT spec bottle refills but that might not matter that much to you. It does seem much cheaper overall and a simpler system in some ways. Methanol is only about 3+ bucks a gallon. I wouldn't try a combination of 2 or 3 gases.

One problem a lot of guys run into, unknowingly, is to underbuild then stretch the limits too far. That is, they build an engine with components that 'should hold up' at 400 HP, then they go to 425HP-450HP and KABLAM! Far better to build for 600HP and then you've got a clear stretch of road far past your original goal of 400.

One other bit of comment: it's best to decide whether you're going to go the limits or stop at a certain point and call it good. That is, actually knowing what you want and being able to be satisfied with it. That's a tough one and I've been fighting it for many years: MORE POWER, SCOTTY! From that I'd say if you overbuild and can be happy at your planned target HP you could get many miles of good clean [minus the soot] fun.

The top pros will tell you: cylinder/ring sealing is the single most important aspect of building a topnotch engine. Without very careful attention to this factor you can find that you wasted a lot of time, money and effort. Premium quality $$$ machine work and meticulous assembly in EVERY DETAIL can really pay off.

JimmieD
 

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Discussion Starter #10
An HX-40, would NOT be able to supply the pressure that are needed for this, it is out of the map range. Like the HX-35, they can do apx 40lbs but don't like it much. I believe a set of duals will be needed for this pressure. Can the injector pump supply this much fuel? No insult, I know the P7100, not these pumps, yet :)
Here is the question on the mapping of turbo's. Is it simply that they do not like the pressure levels or would it be able to push more LBS if the overall air jammed into the egine is less. Basically I'm saying it can still push the same amount of air but since the 4bt needs less would it be able to provide higher lbs.

Also i think the similar p7100 inline pump for the 4bt will be able to push the fuel for these numers. As for the VE pumps they may be able to do it but I don't think they would hold up.
 

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CHARLES! You're the MAN!

I believe that is the best explaination I have heard on the topic. I am VERY impressed. T h a n k Y o u.

Better than any book I have attempted to read on the subject! Not that many books are covering multiple(in any style) turbo setups.
 

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Discussion Starter #13
Dizamn Charles,


That is the best explanation I have ever heard as well. I now understand much better. I still need practice reading maps but I fully understand the ....if I am stating this right... compound turbo set up?

Is this correct?

The differences in terms such as compounds, twins, ect?

But yes thank you again that was a very good explanation. All the more reason reaffirming why I would like to put a twin turbo set up on this puppy. I think the 4bt would be very happy with one.
 

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Discussion Starter #15 (Edited)
Hey Charles,

I will do a bit of research on what I plan to use and get back to you then. Thank you for the help that would be excellent. I really do hope to have the first 400HP 4BT out there. Trust me when the truck is blowing people away at the Dyno's I'll be sure to mention your names as so far on my own I am completely incapable of designing such an engine.

As far as peak power I assume where in the power range I want the peak power to be. To tell you the truth I don't care where it is as long as I can get to that 400HP mark. I really don't know which intercooler I am going to use yet. What is the usual standard level or PSI boost lost in an intercooler? I am probably not going to be using anything really large as there is not a lot of room on this 56 F-100 and I don't plan on ever pulling anything and don't really plan on doing anything but a few 1/8th and fewer 1/4 mile drags just to say I did and use that power.

Hoping to get into the 60 PSI level
 

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??????????????????????/// i,d love to be there for this sperience 200+ hp for a highway truck + it live. thats like taking a 250 hp sbc and making a nascar engine out of it 800 hp and wanting it to go 100,000 miles. hope you got super deep pockets cauz your gonna need em...
 

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In the very nature of compounding the first stage must be larger than the second on the order nearly equal to the pressure ratio it delivers to the second stage. (In the example I gave it would need to be around twice as "big" or more depending on other conditions)
This is the part I'm most highly interested in. I have heard people talking about size differences between compound turbos of as little as 20% (sizing the little one at 90% and the large at 110% of a single turbo flow), this is the first time I've heard of making the big one double.

Of course it will depend entirely on the application. When I get around to trying it my goal is boost at low rpm's and holding through to the highest rpm's you use in normal driving. I'm after maximum drivability and no smoke.
So for me the larger turbo will only be sized big enough to flow the expected maximum airflow.

Quite different to making a dyno queen where the only concern is power. This is always going to lead you to bigger turbos for their lower exhaust backpressure and hitting good efficiency at the engines maximum flow.
 

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Discussion Starter #18
Dang it bob I just realized I forgot to give you a call. Should be getting ahold of nate sometime this week.

But as far as the drivablility of the truck for 100,000 thousand miles I agree. In all reality I probably don't plan to put 10,000 miles on the truck in the next 10 years.

I agree in overbuilding the engine and not pushing it to its limits as stated in an earlier thread. I would love to make it to 400HP on #2 only but a nice shot of propane or methanol/water injection, or nitrous a few times would be ok I think and I don't plan on pushing the engine farther than I think it can go after building it.

But there are more than 4 or 5 out there with the 6bt that use their 600 + HP trucks as everyday drivers. When they get crazy with things they sometimes break them that is true. But I think I can handle 1 or 2 things breaking over the period of 10 years.

No I don't have deep pockets either....far from it, but this project will come in stride over the next couple years (stilll working on the truck itself) and hopefully with some ingenuity or should I say enginuity and my own fab work I hope to keep the costs down.
 

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