I discussed this quite a bit with Justin before ordering my pump. I told him I wanted a DB4 and he asked me 150cc or 180cc? I told him I wanted the all-out 180cc because my long block will be capable of supporting it so why not? Right? Well, a couple sacrifices had to be made to get that much out of the pump. One is locked out timing and cold advance mechanism delete. I already have concerns about cold starts with lowered compression. I don't need HPCA delete making this worse. His website also says "due to the nature of the governor resolution, this pump is not recommended for daily drivers". I asked him how much of a problem this is, and he said the 180cc for the guy who wants to just run it and does not care how it acts. Like I said, the 180cc is on the fringe edge of what is possible with a rotary pump. If I were building a truck for sled pulls or dirt drags, then I'd want the 180cc. Since I still want to be able to back my travel trailer into a camp spot and gently maneuver 4x4 roads I went with the 150cc. That's why he offers it. It's the "street" DB4, it says it right in his website. Before somebody calls me on it... I know. It's a limitation of the DB pump, not the horsepower level per se. But we are talking about IDI builds and that's where we are at when it comes to bolt on fuel.
how to make real HP with your IDI
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I discussed this quite a bit with Justin before ordering my pump. I told him I wanted a DB4 and he asked me 150cc or 180cc? I told him I wanted the all-out 180cc because my long block will be capable of supporting it so why not? Right? Well, a couple sacrifices had to be made to get that much out of the pump. One is locked out timing and cold advance mechanism delete. I already have concerns about cold starts with lowered compression. I don't need HPCA delete making this worse. His website also says "due to the nature of the governor resolution, this pump is not recommended for daily drivers". I asked him how much of a problem this is, and he said the 180cc for the guy who wants to just run it and does not care how it acts. Like I said, the 180cc is on the fringe edge of what is possible with a rotary pump. If I were building a truck for sled pulls or dirt drags, then I'd want the 180cc. Since I still want to be able to back my travel trailer into a camp spot and gently maneuver 4x4 roads I went with the 150cc. That's why he offers it. It's the "street" DB4, it says it right in his website. Before somebody calls me on it... I know. It's a limitation of the DB pump, not the horsepower level per se. But we are talking about IDI builds and that's where we are at when it comes to bolt on fuel.
88 Ford
Full Access Member
I apologize. Its hard to always interpret meaning in posts. Now back to the thread.
88 Ford
Full Access Member
I think the RD150 is definitely a happy medium with a mechanical pump and higher power. It still gives you a bit more tuning ability. The only way to have real driveability and high power in such an old truck would be to adapt a newer electronic injection system. I've been researching and thinking that common rail injection from a Duramax wouldn't be that hard. I believe the pump spins the correct direction and the injectors would need some sort of cup to adapt the injectors into the standard idi injector spot. The electronics would be pretty easy for me and with EFI Live you can adjust and control the CP3 injection pressure. I think the LBZ injection system might be the easiest to adapt. Its just something I've been contemplating. Do you have a build thread somewhere? I must have missed it.
satx78247
Full Access Member
To All,
I've found some wrecked IH school buses with turbo-ed IDI Navistar engines at a local scrap yard.
Are all the turbos for IDI 6.9 & 7.3 engines interchangeable??
yours, satx
I've found some wrecked IH school buses with turbo-ed IDI Navistar engines at a local scrap yard.
Are all the turbos for IDI 6.9 & 7.3 engines interchangeable??
yours, satx
Factory turbos, like ATS 093? If so, each complete setup, manifolds to downpipe, airbox, intake snail etc. would fetch nearly a grand, and there's plenty of hunger for those kits here. Including me if I had the extra cash and desperation to switch to a waste gated turbo. Sounds like a good find if you ask me!
satx78247
Full Access Member
Koch13351,
I don't know enough about turbos to know for sure but probably YES I think "factory installations" & the engines are "just sitting there", so I'm wondering if all the school bus IDI Navistar engines are essentially the same/interchangeable??
(This is a scrap yard, rather than a wrecking yard & I suspect that buying a whole engine will be cheap.)
Btw, when I didn't need one, I knew where "a school bus graveyard" was up near Lufkin & those were eventually sold by the pound for scrap iron.
yours, satx
I don't know enough about turbos to know for sure but probably YES I think "factory installations" & the engines are "just sitting there", so I'm wondering if all the school bus IDI Navistar engines are essentially the same/interchangeable??
(This is a scrap yard, rather than a wrecking yard & I suspect that buying a whole engine will be cheap.)
Btw, when I didn't need one, I knew where "a school bus graveyard" was up near Lufkin & those were eventually sold by the pound for scrap iron.
yours, satx
satx78247
Full Access Member
Koch13351,
THANKS. = I'll go look in the next day or two.
yours, satx
THANKS. = I'll go look in the next day or two.
yours, satx
I don't have a build thread yet but I will. There are just so many dead-end "idea" threads out there that I wanted to have all my parts and some good solid progress going before posting it up.
For my uses and my budget the 150cc is a good place to stop. Remember Justin's bronco was only running ~160-ish because of the lift pump pressure. The 150cc should be very similar to that. Justin was slipping a 13" Southbend clutch. That is the best you can do with a manual, and I dis-like auto transmissions. Add more fuel and you realistically need a built auto to get the power to the ground. As far as the electronic fuel systems, that pretty much defeats the whole reason I like the IDI. I am partial to the durable simplicity of an all mechanical engine. I know our pumps are not the greatest design, so I would like to see the inline and/or V pump come to fruition... but more for durability and better tuning than for additional fuel.
88 Ford
Full Access Member
You are right about the lift pump. I wonder if that held the Db2 back as well? And yeah I wonder if maybe a NV5600 would hold the power better. That could be a possibility for a swap.
Additionally, I do understand your reasoning about a mechanical pump. It was just something I just have an interest in. One thing about our pumps is they may not fuel very well up high but they do very well down low. I think with a compound turbo setup, the fuel might be better used. The Bosch VE pumps on first gen Cummins are rotary as well and do much better with twins than a single turbo...
Additionally, I do understand your reasoning about a mechanical pump. It was just something I just have an interest in. One thing about our pumps is they may not fuel very well up high but they do very well down low. I think with a compound turbo setup, the fuel might be better used. The Bosch VE pumps on first gen Cummins are rotary as well and do much better with twins than a single turbo...
I think that is what Justin wants to make (eventually) is a custom gear housing to mount an 8 cyl Bosch V pump. That would be awesome, but costly. The NV5600 is not any more robust than a ZF5. A ZF6 is a tad bit stronger and not hard to adapt, but the real issue isn't the trans itself it's the clutch. Our flywheel can be re-drilled for a 13" Superduty clutch (what you would use with a ZF6) and you can get a 13" friction disc that jives with ZF5 splines... But 13" is the max. Beyond that you would need a dual disc. Justin looked into it and basically it is not going to happen for us. I think he is going to keep using the ZF5 in his Bronco, but it is a performance limitation. Obviously the heavier the truck the more of a limitation it is, and the Bronco is pretty light for an IDI.
88 Ford
Full Access Member
The thing is, you can get a dual disc clutch with a NV5600. That would be a decent upgrade is the situation necessitated it. I definitely think you will be alright with a 13" clutch with your setup and RD150 though.
88 Ford
Full Access Member
I found this for the ZF6. I wonder if we could have the flywheel machined to accept it on ZF5? Or would it just have to be used with a ZF6?
http://www.blackclouddiesel.com/pro...dual-disc-clutch-6sp-ford-7-3l-1999-2003.html
http://www.blackclouddiesel.com/pro...dual-disc-clutch-6sp-ford-7-3l-1999-2003.html
icanfixall
Official GMM hand model
88 Ford. I have a feeling you are calling me out .... If so I'm ok with that. Justin has done and will do for the idi what NOBODY else can or will do. Please ask Justin about D young's pump issues that Dennis got from him. I'm not here to destroy Justin's reputation at ALL. You seem enamored with him and what he has accomplished. Many are and that's not a problem for me and should not be an issue for anyone. when you push the limits things are expected to fail. Its how we find the limits. If I was to push the limits like Justin has and has done consistently I would take more readings from every possible location. But he does not as can clearly been seen in your post about installing a different pump and rolling it on the dyno timed by ear. Then finding it was 17 degrees advanced. This was MY concern when he first put power to the ground on the first big build with nothing but a boost gauge connected. I was actually shocked a person would put so much money and time into something and have nothing to show what was going on. No temp, oil pressure or pyro showing any IMPORTANT information. In the end that engine blew a head gasket because of the rush to install it he and his friend installed a piston backwards.
The
ricardo cup was at the bottom on the cylinder instead of at the top where the precup blows into it. He never did post a reason or a pic of that failure. Of course I saw it here as many others did. We all make mistakes and might be embarrassed about the. That is part of life. But please investigate what you are saying. Know your facts. In closing this post I continue to support what Justin does.
The
ricardo cup was at the bottom on the cylinder instead of at the top where the precup blows into it. He never did post a reason or a pic of that failure. Of course I saw it here as many others did. We all make mistakes and might be embarrassed about the. That is part of life. But please investigate what you are saying. Know your facts. In closing this post I continue to support what Justin does.
there is definitely a lot of good info on this thread. does any one know why an IDI wont start well with lower compression? also has anyone tried to use a compound turbo from a 6.4, or would it not work.
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