Performance engine parts

[Pearl_Diesel]

Another question, does anybody make performance pistons, rods, stroker kits, cranks, heads, intake manifolds, etc... for the IDI's? I've heard a few about head studs, rods and pistons, but not an awful lot.

 

[ameristar1]

Naw buddy, the vast majority of the stuff is usually one off custom because there isn't much demand for it. Until you see someone get a lot of power out of these things AND be able to drive them on the street, it won't happen. But we're working on it.

 

[Pearl_Diesel]

Well, that shoots a good sized hole in my engine build up plans.

 

[icanfixall]

Give Barnett Performance a call. They claim to offer a stroker short or long block. Also offer head porting but... I'm not sure what they do about porting that I haven't already done. Its interesting reading anyway. Mel Agne offers a great pump and injectors and Russ (Typ4) offers plenty of turbo, injector and cam help. Others are trying to find some cam designs that will help. A turbo piston from Mahle with the top either hard anadoised or creamic coated is really all you need. All the 6.9 and 7.3 motors have exactly the same internal parts. The crank, rods, oil pump, cam, lifters, gears and most everything are the same part number so don't let someone tell you something wont fit. Yes, the pistons and heads are differant but thats about it.

 

[ameristar1]

Not necessarily. The good thing about the IDI is that the heads and intake are pretty good, the ports are huge. That's more important than anything to make power. The limitations are these:

Fuel injection system: The stock DB2 pump pretty much runs out of steam at about 300hp or so and the injectors don't exactly flow a ton.

The camshaft: ZZZZZZzzzzzz. .380" lift/zip for duration and a late intake valve closing event don't exactly set the world on fire for a forced induction application. Motor is fighting itself, limiting power. We have been getting after the cam question pretty hard lately, and hopefully soon we'll have solutions in the form of custom ground cams. Russ |(typ4) already has a regrind (high torque special) that works good with a turbo. But until we understand how much piston to valve clearance we're working with, we can't get a killer grind together. Hopefully we'll have that worked out soon.

Once these two issues get sorted, the motor will kick butt. Getting turbos, superchargers or other things adapted to these engines is not really the issue.

 

[hesutton]

Here's the link: BARNETT HIGH PERFORMANCE.

I emailed them a month or so ago asking about their HP IDI stuff and here is the response.

It all depends on the application and the power level wanted. If it is race or pull application and there not worried about streetable then we can do some crazy stuff. The higher powers get aftermarket rods pistons and crank and compression again depends on the application. We dont sell with injectors usually unless a turnkey engine is required then we buy or have someone modify them.
Pretty soon we will offer a aftermarket block short block or long block as soon we will have a source for aftermarket blocks.
The twin turbo unit we do are custom and can be made several different ways again depends on the application.
The streetable engine we build are just that streetable and work well on the street and run very much like a stock engine does.


Thank you for this chance to serve your engine needs!
From Tim Barnett of
Barnett High Performance 517 719 5185

Heath

 

[diesel4me2]

Russ |(typ4) already has a regrind (high torque special) that works good with a turbo. But until we understand how much piston to valve clearance we're working with, we can't get a killer grind together. Hopefully we'll have that worked out soon.

so, just for my understanding, that only is a concern if your running a stock piston, correct? ... my pistons don't protrude out of my block at all. i don't even have valve recesses in the top of the pistons any more.

 

[ameristar1]

so, just for my understanding, that only is a concern if your running a stock piston, correct? ... my pistons don't protrude out of my block at all. i don't even have valve recesses in the top of the pistons any more.

Exactly, since the stock configuration pokes the pistons out of the block a bit.
We need to mock some motors up, both 6.9 and 7.3 with stock and modified piston set ups so we can see how much room there is.

Is that something you'd be willing to do with your engine, to share with the forum?

 

[diesel4me2]

Is that something you'd be willing to do with your engine, to share with the forum?

if you can give me some time. i do have a spare 7.3 on the stand right now. haven't had time to tear into her yet. give me the weekend to clean up the garage and i should be able to do something next week, if all goes well

 

[ameristar1]

Well, that shoots a good sized hole in my engine build up plans.

By the way, what would you like to do as a buildup for your IDI?

 

[icanfixall]

All the pistons I have measured have a dome thickness of between 560 and 580 thousands. All of the pistons measured are stock 1989 Mahle oem and the new turbo pistons from Mahle. I can supply the newer piston part numbers if needed. I'm running a set of Mahle turbo low compression pistons that have been milled 12 thousands. The milng was because they stock Mahle turbo pistons were over 45 tousands above the deck... The fools at the machine shop milled the deck twice... Yeah, I know.... Why wasn't doing it once good enough.... All the pistons are where I wanted them tbe at 24 to 26 tousands above the deck... The factory setting of 31 thousands is themax setting. They can be less from the factory. I actually ran the first motor at 54 thousands above the deck. Every piston had a valve kiss in it when the motor came apart. None of them were deep enough to measure and believe me I tred. It was just something you could see but not feel. Most fingers can feel half a thousands. All my depth micscouldn't find any demension... I still have those pistons. I'll brng them to the next rally....

 

[ameristar1]

All the pistons I have measured have a dome thickness of between 560 and 580 thousands. All of the pistons measured are stock 1989 Mahle oem and the new turbo pistons from Mahle. I can supply the newer piston part numbers if needed. I'm running a set of Mahle turbo low compression pistons that have been milled 12 thousands. The milng was because they stock Mahle turbo pistons were over 45 tousands above the deck... The fools at the machine shop milled the deck twice... Yeah, I know.... Why wasn't doing it once good enough.... All the pistons are where I wanted them tbe at 24 to 26 tousands above the deck... The factory setting of 31 thousands is themax setting. They can be less from the factory. I actually ran the first motor at 54 thousands above the deck. Every piston had a valve kiss in it when the motor came apart. None of them were deep enough to measure and believe me I tred. It was just something you could see but not feel. Most fingers can feel half a thousands. All my depth micscouldn't find any demension... I still have those pistons. I'll brng them to the next rally....

I think the safe measure should be at least .090" or better, something like .100 should be more than enough given the motor won't be revved high enough to really stretch the rods. Can a zero deck height be achieved with off the shelf pistons or will some have to be made to drop the piston down somewhat, then adjust the clearance with gasket thickness? At least it'll free up some room.

Does the IH manual have all the dimensions of the motor? Bore, stroke, connecting rod center to center length, etc.

 

[david85]

Here is what I found just now:

Cylinder Head Specifications On
Navistar International 6.9L Engines

Due to the extremely close running clearances between the pistons and valves and the pistons and cylinder head, it is extremely important to maintain the proper specifications on this engine when performing cylinder head rebuilding operations.

The cylinder head thickness should be maintained between 4.795 and 4.805. Figure 1 shows that this measurement is taken from the deck surface to the valve cover rail.

Figure 2 shows the valve angles for the Navistar 6.9L engine. Notice that the exhaust valve angle is 37 1/2° while the intake valve angle is 30°. The valve seats have the same angles as the valves.

Again, due to very close running clearances, proper valve recession must be maintained. There is only .009 running clearance between the exhaust valve and the piston when the exhaust valve is fully open. The recession specifications are as follows:

Intake: .042-.054 (1.06mm-1.37mm) A and B models
Exhaust: .043-.055 (1.09mm-1.40mm) A models *
Exhaust: .046-.058 (1.17mm-1.47mm) B models *

* All exhaust valves serviced through Navistar are the B valves only, Navistar part #1 805 917 C1. Use the B specification with all new exhaust valves and the A specification on reused valves where applicable.

When reassembling the Navistar 6.9L cylinder heads, you must snap the valve stem seal onto the bottom of the valve spring retainer. Failure to do so may create coil bind.

The AERA Technical Committee

source:
http://www.automotix.net/autorepair/international-scout_ii-engine_repair_guide-726.html

 

[ameristar1]

Man Dave, thanx! It's almost disturbing, that they clearanced the motor so tightly. You literally have to reconfigure the whole deal just to put some room in there to let it breathe. Valves are going to meet pistons way too easily if nothing is done. Why they set a fleet engine up as an interference motor I just don't get.

It may require a combination of deep notches, lowered compression height and thicker gaskets. Time to do the math. I still can't believe .009" running clearance. The engineers must have smoked some really good drugs that day.

 

[david85]

I remembered reading about the crazy tight clearences somewhere but I thought it was closer to 25 thou. Glad I looked it up because I was a little off.

Found this too:

http://www.rebuiltautoengines.com/international-1100d-articles.html

When I rebuilt my engine I did find one of the pistons with a valve imprint on it. Nothing major, just enough to leave a mark. At least the valves are verticle to the pistons

It is also a gear driven engine instead of chain or (gasp) belt in the case of light duty diesels, so the chances of that clearance getting out of spec are fairly unlikely.