performance rebuild
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Posting Guru
Joined: Jul 2006
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From: Cleburne
performance rebuild
I'm going to rebuild my 7.3, banks sidewinder turbocharged, 89 f250 4x4. would like to do a performance rebuild. I've found a place to get perf injectors and pump(dps-performance.com), thanks to this forum. Does anybody know where to get other performance stuff for 89 7.3. Things such as over sized pistons, cam shafts, oil pumps, gasket sets, ring sets, bearing sets ect... Also is there any info available on perf rebuilding regarding the 7.3. such as caming, propane and porting heads ect... Any help or recomendations would be greatly appreciated. I want to beat the new guys w/old school. Thanks for all of your help fellas!
Last edited by Royson12; Aug 24, 2006 at 04:46 PM. Reason: left out truck info
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
Find a 6.9 and build that, a 7.3 bored is a ticking time bomb.
Standard proceedure is over bore it, then sleeve the block back to stock bore.
I had three sleeved engines and will never own another one.
Blew three up with cracked blocks in 28,000 miles.
Yes you can buy 20,30 and 40 over pistons for a 7.3, but cavitation is already a problem with the stock bore. 20 or 30 over would just make it that much more of an issue.
Standard proceedure is over bore it, then sleeve the block back to stock bore.
I had three sleeved engines and will never own another one.
Blew three up with cracked blocks in 28,000 miles.
Yes you can buy 20,30 and 40 over pistons for a 7.3, but cavitation is already a problem with the stock bore. 20 or 30 over would just make it that much more of an issue.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
If the cylinder bore is worn, you have to do something to straighten it up.
Boring is about the only option.
A 6.9 has a 4" bore.
To make it a 7.3 they bored it out 110 thousandths.
The block is the same basic block although there were a few minor improvements.
The biggest thing that was an improvement was going from 7/16" head bolts on the 6.9 to 1/2" head bolts on the 7.3.
If you are planning high boost you need head studs in either motor.
When I rebuilt my salvage yard 6.9, it had already been bored 20 over.
My machine shop was able to get the cylinders to clean up with an additional 10 thou.
So I am 30 over on a 6.9 block, which still leaves the cylinder walls 80 thou. thicker than a stock 7.3 cylinder wall is.
Almost all the parts on a 7.3 and 6.9 will interchange except the rings, pistons heads, and head bolts. Some of the 93 and 94 factory turbo engines also had different connecting rods with bigger wrist pins.
If I were looking for a 6.9 I would be looking for an 85 thru 87 model. Some of the 83 and 84 blocks had issues with the block heater area cracking.
Run 7.3 rockers.
Get head studs from ARP or DPS.
If you want to run big boost you may want to mill the piston tops down to lower the base compression ratio but this can cause start problems. DPS can guide you there.
80 thou off a Sealed Power hypereutectic piston drops the commpression to 18 to 1, with head studs you can run 25 plus pounds of boost.
DPS IP and Stage 1 injectors.
Ken (DPS) also has a stronger valve spring package that lets you run higher RPM.
You can do porting and custom cams as well as a few other things, but drivability may be a side price you have to pay for totally awesome power.
I took 50 off my pistons which dropped my compression to 19.5 to 1 in round numbers.
Lost a little bottom end torque, dropped the EGT 350 degrees at WOT and gave me more top end power because I cranked the boost to 19.5 PSI. I still have not turned the pump up more since I don't have many miles on it yet.
Where the pump is set it smoked like a Mack running 14 PSI at WOT.
Now it barely smokes at all once the RPM gets to 2000 with the higher boost.
I even get between 1 and 2 MPG more unless I stand on it taking off with the loads I haul. 20 K gross was about 9 MPG before, now I am getting between 10 and 11 with the same loads here in the mountains.
Yes you can do propane and/or water methanol injection, you can also run an intercooler when the boost numbers get high.
They all have a power potential, but there are also some potential side costs with all of them. I have intentions of running propane at low levels to help increase the MPG, but I have to get a frame mounted tank so I have a place to put it. The last time I priced them they were about 500 dollars when steel prices took the first couple of hikes. I would also like to run an intercooler, but I have to trade snow plows to do that. My mounting bracket is right in the middle of where the intercooler would mount. If we don't get more snow this year than we did last year I will be taking it off anyway.
Boring is about the only option.
A 6.9 has a 4" bore.
To make it a 7.3 they bored it out 110 thousandths.
The block is the same basic block although there were a few minor improvements.
The biggest thing that was an improvement was going from 7/16" head bolts on the 6.9 to 1/2" head bolts on the 7.3.
If you are planning high boost you need head studs in either motor.
When I rebuilt my salvage yard 6.9, it had already been bored 20 over.
My machine shop was able to get the cylinders to clean up with an additional 10 thou.
So I am 30 over on a 6.9 block, which still leaves the cylinder walls 80 thou. thicker than a stock 7.3 cylinder wall is.
Almost all the parts on a 7.3 and 6.9 will interchange except the rings, pistons heads, and head bolts. Some of the 93 and 94 factory turbo engines also had different connecting rods with bigger wrist pins.
If I were looking for a 6.9 I would be looking for an 85 thru 87 model. Some of the 83 and 84 blocks had issues with the block heater area cracking.
Run 7.3 rockers.
Get head studs from ARP or DPS.
If you want to run big boost you may want to mill the piston tops down to lower the base compression ratio but this can cause start problems. DPS can guide you there.
80 thou off a Sealed Power hypereutectic piston drops the commpression to 18 to 1, with head studs you can run 25 plus pounds of boost.
DPS IP and Stage 1 injectors.
Ken (DPS) also has a stronger valve spring package that lets you run higher RPM.
You can do porting and custom cams as well as a few other things, but drivability may be a side price you have to pay for totally awesome power.
I took 50 off my pistons which dropped my compression to 19.5 to 1 in round numbers.
Lost a little bottom end torque, dropped the EGT 350 degrees at WOT and gave me more top end power because I cranked the boost to 19.5 PSI. I still have not turned the pump up more since I don't have many miles on it yet.
Where the pump is set it smoked like a Mack running 14 PSI at WOT.
Now it barely smokes at all once the RPM gets to 2000 with the higher boost.
I even get between 1 and 2 MPG more unless I stand on it taking off with the loads I haul. 20 K gross was about 9 MPG before, now I am getting between 10 and 11 with the same loads here in the mountains.
Yes you can do propane and/or water methanol injection, you can also run an intercooler when the boost numbers get high.
They all have a power potential, but there are also some potential side costs with all of them. I have intentions of running propane at low levels to help increase the MPG, but I have to get a frame mounted tank so I have a place to put it. The last time I priced them they were about 500 dollars when steel prices took the first couple of hikes. I would also like to run an intercooler, but I have to trade snow plows to do that. My mounting bracket is right in the middle of where the intercooler would mount. If we don't get more snow this year than we did last year I will be taking it off anyway.
Last edited by Dave Sponaugle; Aug 25, 2006 at 10:33 PM.
Thread Starter
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Posting Guru
Joined: Jul 2006
Posts: 1,148
Likes: 13
From: Cleburne
It sure sounds like you know your stuff. Thanks for all of your info. Just dropped a valve, i think in my truck, time to rebuild sooner than i thought. i want a truck capable of being a daily driver, just want to be give these younger trucks a run for their money. prove once and for all you cant replace a good shade tree, with a computer chip. Or at least the satifaction i will get when I tell em i did it not a computer chip. luv this forum!
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
I gave an engine remanufacturer 4 tries at a reman engine.
Then I gave a salvage yard 1 attempt at an engine.
This is all in the last 2.5 years.
I built this one myself, I have not done any serious wrenching in many years.
I think I can do a lot better than some of the so called proffesional engine rebuilders from what I have seen for workmanship in the engines I bought.
Then I gave a salvage yard 1 attempt at an engine.
This is all in the last 2.5 years.
I built this one myself, I have not done any serious wrenching in many years.
I think I can do a lot better than some of the so called proffesional engine rebuilders from what I have seen for workmanship in the engines I bought.
