Why do the freeze plugs become an issue? Is it boost getting into the coolant system or just heat from the boost?
Builds Big Red Toy (17 Viewers)
- Thread starter The Phoenician
- Start date
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It's the heat from the boost. A fine layer of the coolant touching the cylinder wall can vaporize under high boost conditions and when coolant turns to steam it increases in pressure. Aside from that it is how a block flows coolant. The cummins can get a higher pressure at the rear of the block under higher power conditions and the freeze plugs are usually what go. Even when the thermostat is open and the radiator cap is relieving pressure the back of the block can see higher pressure.
It's usually not just high boost alone but coupled with higher rpm. I was at 2800rpm the first time my side plug popped out. The cummins water pump flows really well and some will clip the tips of the fins to reduce it's efficiency. That may be fine for a sled puller but I didn't like that direction for a street truck so a coolant bypass takes care of that concern.
A coolant bypass is installed in place of the rear freeze plug and that relieves the pressure with a safety valve (like your water heater in your house) and usually dumps it in the top of the radiator (bottom of the radiator is the intake for the engine). For a cummins I have not found anyone who has actually measured the pressure when a freeze plug pops but I have read some that speculate it somewhere in the 80-90psi range. In my coolant bypass set up I'm running a 35psi rated valve to take care of the higher pressures.
It's usually not just high boost alone but coupled with higher rpm. I was at 2800rpm the first time my side plug popped out. The cummins water pump flows really well and some will clip the tips of the fins to reduce it's efficiency. That may be fine for a sled puller but I didn't like that direction for a street truck so a coolant bypass takes care of that concern.
A coolant bypass is installed in place of the rear freeze plug and that relieves the pressure with a safety valve (like your water heater in your house) and usually dumps it in the top of the radiator (bottom of the radiator is the intake for the engine). For a cummins I have not found anyone who has actually measured the pressure when a freeze plug pops but I have read some that speculate it somewhere in the 80-90psi range. In my coolant bypass set up I'm running a 35psi rated valve to take care of the higher pressures.
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- Thread starter
- #2,863
Found this with no details on turbo sizes. This more if anyone else is interested. I'm going to take my time to weight out the pros and cons.
Cummins 4bt 6bt Twin turbo Jeep CJ7 project | eBay
Cummins 4bt 6bt Twin turbo Jeep CJ7 project | eBay
- Thread starter
- #2,864
figure out a configuration to take my bikes and the bbq pit. Gonna be a great Thanksgiving camping trip.
Happy Thanksgiving everyone.
Happy Thanksgiving everyone.
Details to the hitch mounted bbq??? I have always wanted to homebrew one like that but never had the time
happy camping+thanksgiving! Im doing the same on Friday with some buddies
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Thanks Mike!
I've made a couple for the MUD guys.
The one for my 100 rig will be a dual fuel--- gas and charcoal/wood.
- Thread starter
- #2,869
Just got back from a two day camping trip with family. Had a blast, hope everyone here also enjoyed Thanksgiving with those that matter to them the most.
Got there early so I can pick where to set up the RTT. After that I put up my 8 man tent for the rest of the family.
Had to back it up over the concrete stop so the awning wouldn't hit the tree.
Many people kept stopping by to check out the set up. A few of them had Land Cruisers but sold them a while ago and expressed how much they regretted it that.
And now for the annoying news. Since I've gone to New Mexico I've developed a slow but consistent drip. I can't tell if it's from the rear main seal or the transmission box since it seems to pool around the bell housing.
It's hard to tell, but there's a drop at the very bottom of the bellhousing where the oil pools then drips to the driveway. I'm beginning to get some real flack about it so I guess it's on my immediate plan to fix. Here's my question, do i have to pull out the entire engine to do teh rear main? If so they I might as well replace a few other things like the motor mounts and probably do a bypass for the rear freeze plug like @ boots4 so when the time comes it will be ready for the second turbo.
Got there early so I can pick where to set up the RTT. After that I put up my 8 man tent for the rest of the family.
Had to back it up over the concrete stop so the awning wouldn't hit the tree.
Many people kept stopping by to check out the set up. A few of them had Land Cruisers but sold them a while ago and expressed how much they regretted it that.
And now for the annoying news. Since I've gone to New Mexico I've developed a slow but consistent drip. I can't tell if it's from the rear main seal or the transmission box since it seems to pool around the bell housing.
It's hard to tell, but there's a drop at the very bottom of the bellhousing where the oil pools then drips to the driveway. I'm beginning to get some real flack about it so I guess it's on my immediate plan to fix. Here's my question, do i have to pull out the entire engine to do teh rear main? If so they I might as well replace a few other things like the motor mounts and probably do a bypass for the rear freeze plug like @ boots4 so when the time comes it will be ready for the second turbo.
Do you see any drips at the back of the #4 cylinder valve cover?
Yes, either the engine has to come out or the transmission has to come out to do the rear main.
Yes, either the engine has to come out or the transmission has to come out to do the rear main.
- Thread starter
- #2,871
No oil at the back of #4 cylinder valve cover
.
Only other place it could come from is the pushrod cover behind the injection pump. Any oil coming from the DS of the engine towards the rear of the block?
Some other spots I can think of: I've fought with a leaky turbo oil drain that had oil traveling to that same spot under the bell housing. So check the passenger side of the engine too for leaks. Could also be an oil pan gasket.
- Thread starter
- #2,874
I have it narrowed down to either the pan is leaking from the rear, the rear main or possibly even the transmission is leaking into the bell housing. Need a weekend to figure it out.
You could smell if its gear oil, no?
- Thread starter
- #2,876
I've been off in Nevada doing some training at Fallon.
Was doing some training and the pilots let me hang out in the maintenance bay for a while.
meanwhile Little Red and Big Red both were getting some work done.
Little Red found her long lost sister
Drove Little Red back from getting some work done and had a rear tire blow out at 120mph. She handled it great.
While Big Red was getting her wiring taken care of
Still have to figure out the oil leak, but that's next week's problem.
Was doing some training and the pilots let me hang out in the maintenance bay for a while.
meanwhile Little Red and Big Red both were getting some work done.
Little Red found her long lost sister
Drove Little Red back from getting some work done and had a rear tire blow out at 120mph. She handled it great.
While Big Red was getting her wiring taken care of
Still have to figure out the oil leak, but that's next week's problem.
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- Thread starter
- #2,877
Tranny is out for an input shaft seal.
Putting it back in tomorrow. What readily available gear oil are you NV4500 folks using? I was using Amsoil with no issues, but I don't want to wait until they ship it to me since I hope to be using Big Red this weekend.
So thinking of Royal Purple 75w90 since it's available at the local store and I have an Oreilly's gift card. Any other suggestions or recommendations?
One diesel mechanic suggested using straight 50w oil, but I have my reservations since there are brass synchros in there.
Thoughts?
Putting it back in tomorrow. What readily available gear oil are you NV4500 folks using? I was using Amsoil with no issues, but I don't want to wait until they ship it to me since I hope to be using Big Red this weekend.
So thinking of Royal Purple 75w90 since it's available at the local store and I have an Oreilly's gift card. Any other suggestions or recommendations?
One diesel mechanic suggested using straight 50w oil, but I have my reservations since there are brass synchros in there.
Thoughts?
Drive down to your local dodge/ram dealership and pick up some oil from them for your "98 dodge ram diesel with 5 speed". They'll have it in stock, but it'll cost you.
Unfortunately we can't use normal gear oils in the NV4500.
Unfortunately we can't use normal gear oils in the NV4500.
- Thread starter
- #2,879
that's exactly the scenario i'm trying to avoid. Christmas was expensive this year
.
that's exactly the scenario i'm trying to avoid. Christmas was expensive this year
Last time I bought it through amazon, cheapest price I can find, $30 a quart. Do not run a regular gear oil, you will fry the synchros if you do.
Amazon.com: ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid - 1 qt: Automotive
