Magnum engine questions

I'm looking at doing this same swap. Mine is a 1997 with a 2.5 now and a manual. I'll stay manual for sure. Will I need a PCM from a 1997 truck or Durango to make my gauges work? Or should I just use two 2.5 PCM's and double the gauge read out to run the V8??? :ROFLMAO:
 
High Line said:
I'm looking at doing this same swap. Mine is a 1997 with a 2.5 now and a manual. I'll stay manual for sure. Will I need a PCM from a 1997 truck or Durango to make my gauges work? Or should I just use two 2.5 PCM's and double the gauge read out to run the V8??? :ROFLMAO:
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If you are doing the Dodge magnum V-8 swap you use a PCM from a 1998-2000 to match the wiring in your TJ. The 1997 PCM from the Dodge will allow the engine to run but the gauges won't work. The easiest thing to do is get the PCM from your parts rig if it's a Ram 1500 truck and then if it was an automatic send it out to be flashed into a manual transmission PCM.
 
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@Gollywomper I think you'd asked what gains could be had from heads & a cam? Here is a Dyno run results with a before and after cam & EQ heads swapped.

1646969600211.png


2.02 EQ heads, 262/264 .480/.512 cam

Not bad IMO

50 HP & 60 lb ft TQ.
And a good tune would net you 10-20 more in both areas.
 
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I don’t think this Jeep will get a magnum. After I finish the suspension I’m thinking of building a Stroker 2.5. I will continue to wheel and learn with this little light Jeep and build the next one as needed.
 
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Gollywomper said:
I don’t think this Jeep will get a magnum. After I finish the suspension I’m thinking of building a Stroker 2.5. I will continue to wheel and learn with this little light Jeep and build the next one as needed.
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There is nothing wrong with the 4 popper. I'll be honest and say I wish I'd kept it and done things differently with mine but it's way too late to go back.
 
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Wildman said:
There is nothing wrong with the 4 popper. I'll be honest and say I wish I'd kept it and done things differently with mine but it's way too late to go back.
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Yes. There are just too many things that need to be changed to handle HP, tires and low gearing. All of that aside the magnum is the best option for a factory looking v8.
 
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So my 5.9 is finally running and ready to head to the exhaust shop tomorrow. But my clutch is being kind of wonky. There was no bleeder valve on the slave cylinder so I couldn't get that bleed that off initially. Finally replaced that, got it bled and everything, but now my clutch is fully engaged about 1" off the floor. I put a brand new flywheel on the engine when installing (part #PFT-50-2754 from Summit Racing) and a new clutch kit (part #TF-CF178066 from Summit) as well. Both parts are listed as compatible for the 5.2/5.9. I have to push the petal all the way to the floor, I'm completely disengaged, no grinding while rowing gears, the friction point is not even 1/2" from the floor, and fully engaged about 1" from the floor? Any ideas to whats going on??
 
98' 5.9 grands are pretty cheap these days. Got mine for 1200 bux and it needed a trans. To swap that drivetrain in my tj would be ridiculous, the low end torque of the 5.9 geared properly can be great on the trails. Probably better fuel mileage than the 4.0.
 
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TreverStevens said:
So my 5.9 is finally running and ready to head to the exhaust shop tomorrow. But my clutch is being kind of wonky. There was no bleeder valve on the slave cylinder so I couldn't get that bleed that off initially. Finally replaced that, got it bled and everything, but now my clutch is fully engaged about 1" off the floor. I put a brand new flywheel on the engine when installing (part #PFT-50-2754 from Summit Racing) and a new clutch kit (part #TF-CF178066 from Summit) as well. Both parts are listed as compatible for the 5.2/5.9. I have to push the petal all the way to the floor, I'm completely disengaged, no grinding while rowing gears, the friction point is not even 1/2" from the floor, and fully engaged about 1" from the floor? Any ideas to whats going on??
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What slave cylinder are you running?
I read some had to run a longer push rod on the slave to get the clutch where they wanted it to engage.
 
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Gollywomper said:
What slave cylinder are you running?
I read some had to run a longer push rod on the slave to get the clutch where they wanted it to engage.
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I just ordered a replacement for the NV3550 transmission, can't find what brand and part number I ordered right now. But everything I'm finding readily says they fit all years of TJ's.
 
TreverStevens said:
I just ordered a replacement for the NV3550 transmission, can't find what brand and part number I ordered right now. But everything I'm finding readily says they fit all years of TJ's.
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Yes but from all the threads I've read about folks who did the V-8 swap and kept their manual transmission many have had to make or find a longer pushrod for the slave.
One person who had done a 5.2 to start with and then swapped to a 5.9 had to change his slave pushrod.
I made a new one on my CJ5 by getting a bolt long enough to cut the threads and head off. Then cut it to the length I needed.
 
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TreverStevens said:
NV3550 and the Dakota bellhousing.
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I suggest getting a bolt the same diameter as the pushrod in your slave that is about 1" longer after the threads are removed. Then trim it down until you get the correct length.
When I did the clutch in my CJ5 I ended up needing a pushrod about 3/8" longer than the stock pushrod.
 
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TreverStevens said:
@Wildman okay, next question for you. What did you do for your coolant overflow reservoir? Is a 1 liter reservoir enough?
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I tried a few different things but yes I think a 1 liter reservoir should be enough. I don't have any pictures of the one I had mounted before.
 
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Is just about everyone running a 14” circular air filter mounted on the top of their Magnum? I don’t have the stock air box for the TJ so that’s not an option. I’ve been thinking about doing the “mini snorkel” where you go through the firewall and have the filter in the cowl.
 
TreverStevens said:
Is just about everyone running a 14” circular air filter mounted on the top of their Magnum? I don’t have the stock air box for the TJ so that’s not an option. I’ve been thinking about doing the “mini snorkel” where you go through the firewall and have the filter in the cowl.
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I started out with the stock Dodge air hat that you could do that with.

IMG00806[1].jpg
 
Wildman said:
I started out with the stock Dodge air hat that you could do that with.
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Ya, I have the stock air hat with the ribbed tube going to an AirRaid filter that's about where the stock airbox goes. But the filter is a bit weathered and looking to clear up some space in the engine bay.
 
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