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Discussion Starter #1
I have been a member here for quite a while and never had to post cause there is a search button that answered all my questions. Well I spent the last couple of months completly rebuilding a 1979 jeep cj7. The only original parts on my jeep is the steering box and the heater assy. I have a 4bt hooked to a nv4500 and a dana 300. The gears are 3.73 and the tires are 35's. The trial by fire part is that I drove the jeep 820 miles in a day to TN where I now live. I got 22mpg but that was with a trailer and the jeep full of engine parts. The jeep drove great except that I had to downshift to
4th on the hills to keep speed up. I bought a 12cm exhaust housing to take care of that. I also plan on turning the pump up slightly. I will post pics later and still need to get the jeep painted. the noise wasn't as bad as everyone says and the vibes were managable. I did spray the jeep inside and out with lizard skin sound control. well now I can go about making more power with this thing. I plan on making around 160-170hp and of course will need to fabricate a intercooler. I already have a hy35 on a cut manifold that I plan on putting in. I also need to get a dana 44 front for this thing as I don't think the dana 30 is going to hold out much longer.
 

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Discussion Starter #3
I will be swapping gears when I put the lockers and build the front axle. I ordered a 12cm housing from piers today for $177 and plan on doing the pump mods tomorrow and seeing how that goes. I will also put in the egt and the tach before I do the pump mods just to keep a eye on things.
Also at this point I am not ruling out that my turbo is hashed. it didn't turn near as freely as the hy that I plan on putting in and that might be the reason that it doesn't start to spool until real late. any other ideas would be helpful.
 

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Discussion Starter #4
figured out the problem with my motor. I started messing with the pump today and took the power screw out to take off the collar. Before I broke the locknut loose I saw that there was about a 1/8'' before the screw hit the antitamper collar. I broke the nut loose and turned it in three turns. I then took it out and noticed that someone had turned the thing out. It was my understanding that you only got about a 1/4 turn till it hit the antitamper. I took it for a test drive and the thing now runs great. I don't have the lag I used to have at all and the motor seems to idle better. I guess I should have checked the power setting before driving almost 900 miles but I couldn't be happier now. I will put all the gauges in this weekend and then really start messing with the pump and let you guys know how it goes. I need to add some low boost fuel to help spool the pump. Also my 12cm housing should be here by Wed and the spring kit also. I will take pics of the install. Thanks to everyone on here that answered my questions before I even had to ask them
 

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Real nice install, AJ, and I'll bet that thing gets right down the road now? Just a suggestion, but you might consider an aircleaner so you don't suck up every dog, cat and child for miles around! Hah, just kidding. Looks very nice and I admire your Do It Yourself attitude.

By the way, a governor spring installation pictorial would be VERY welcome around these parts....

JimmieD
 

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Discussion Starter #6
here is what I am planning on putting in this weekend. It is the 12cm housing. Right now the jeep runs great but could use a little off the line help. I will test it first without turning up the low boost fuel and then add a little low boost fuel to see what the difference is. I am shooting to not see over 1200 degrees regardless of speed or load on the engine.
 

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Discussion Starter #9
got the new exhaust housing on and now have the EGT gauge in and hooked up. All of this took me approximatly 2 hrs start to finish. The hardest part was seperating the exhaust housing from the center section of the turbo. I had to spray it with penetrating oil and then put it in a bag in the freezer. After that it came right apart. I put the gauge sender in the exhaust housing right after the manifold so it's still pre turbo.
Now for the driving impressions with a 12cm housing. It now drives like a gas engine. The turbo now spools by the time my foot hits the floor and it takes off. Temps on the exhaust never get above 1200 and I have to TRY! to get it there. In normal driving it is never above 8-900 degrees. This is a must perform mod for anyone with a light vehicle. If I had a large truck I would go to a 14cm housing. This thing is a blast to drive. I can now accelerate up hills in 5th gear. I still have to put in the gov spring so I will give you impressions on that after I get that mod done and then it's time to mess with the pump.
 

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That comes as great news, thanks for sharing it!!!:beer:

Acceleration is on demand with no delay which is really good.
I'm wondering if the fuel mileage will be affected either up or down,
since more air, but not(?) more fuel is used...

...also, do the same internals work? (did you just need to buy
the housing?)

Thanks,
George
 

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Sounds great!

My Dads '01 1500 could use a 4BT, but at least it knocks down mid 16's mpg-wise.
 

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Discussion Starter #13
nothing internal needs to be changed on the turbo for this to work. Nothing on the exhaust needs to be changed either. All you have to do is take the four bolts off the exhaust housing and tap it off with a hammer (careful not to damage the exhaust wheel) and then bolt the new housing on. No grinding/welding/fitting needed. just make sure you clock the housing the correct way to begin with and it shouldn't take more than 2 hrs. It would have taken one but I had to chill mine in the freezer to get the housing off cause it was kinda rusty. As for mileage for now it will go down cause I am like a kid playing with the throttle and hearing the turbo spool. When I get used to it mileage should go up cause there is no more downshifting then reving it out then shift just to lose speed. I can hold 5th gear down to about 40mph and then drive up to the speed limit suprisingly quick. Only when I "lug" 5th gear does the EGT's get up to 1200 when I get up above 55 they drop back down to 9-1000.
I just bought a new heater core so that will have to go in before I can start messing with other things
 

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Sounds like the 12cm is more "user friendly" for the lighter vehicles.
Interesting observation, diesel's in general don't downshift so well.
You've probably got your set-up "dialed" because of that housing.

so did you measure the EGT's before the mod? Is it cooler now?

Thanks.
 

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Discussion Starter #15
sadly I didn't measure the egt's before the housing swap. I am currently working on puting in a hydro boost out of a astro van I will get you guys pics on that install when I get it done tomorrow. I have to figure out a spacer as the hydro boost is about 1 3/4" longer. I will get you guys pics on that install tomorrow. Also have to get a new powersteering to hydroboost hose as well as a return.
 

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Discussion Starter #16
Just got done istalling the hydroboost. I used steel spacers to move it out from the firewall. Later I will have a solid steel spacer machined. The brakes now are a joy to drive. With the manual brakes I had to pray that I would have time to stop. now I have to be aware not to press to hard on the brakes. A must upgrade for every Diesel owner. I used a astro van hydroboost and master cylinder and it cost about 120 that includes the new hose from the pump and all little details including the fluid for the pump and brakes. will post pics later
 

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Discussion Starter #18
can't remember what year I got it from just look on ebay they are pretty common. I just put a explorer rear in with disc brakes and it really stops on a dime.
 
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