Thread exclusively to discuss the best ways to build Jeep I6 Stroker motors
Rescue Diver
Full Time Jeeper
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- Kansas City
- Vehicle(s)
- 1979 CJ-7 with a fiberglass body and 1982 wide track axles, 258 I-6 with a 1995 4.0 head, HEI distributor, Motorcraft 2100 Carb, T-18 wide ratio tranny, Super Lift Springs and 33s, a 1997 BMW 328i, and a 2010 REDLINE CONQUEST TEAM Cyclocross Bike. :)
Let's try this again. In this thread, I would like to share what I'm doing, and get input from others specifically pertaining to ways to build 4.6 and 4.7 liter Inline 6 stroker motors.
I decided to pull the trigger on starting my stroker motor project. I'm picking up a good 1995 4.0 donor motor today or tomorrow, and over time I will pick up new Sealed Power dished pistons that should give me roughly 9.25 to 1 compression, getting the block bored either 30 or 60 over, and I'll be using the crank out of my 258 machined 10 under to clean it up.
My plan is to do a cheap but solid build using my 258 crank and rods, the 4.0 block and new pistons, and the stock 4.0 high output cam and lifters. I already have a killer 4.0 head that I'm currently using on my 258, but I also plan to continue using my HEI distributor and MC2100 carb instead of going the fuel injection rout that most do. Unless it shows signs of wear, I think I'll also be re-using the tru roller timing chan I already have in the 258. It only has 25k on it, so I expect to find it still in good shape. I guess I better check to make sure the 4.0 and the 258 take the same chain and gears?
What I've confirmed so far is that the bell housing bolt pattern is the same between the 258 and 4.0. The distributor will also fit. There is a little question on the motor mounts though. From what I gather, the later model 4.0's (TJ's maybe) require a little grinding on the block to get the CJ mounts to clear, but I don't know for sure what year in the 4.0 production that this change occurred. Any input on this would be welcome!
I also discovered that there's a slightly different part number for the oil pump. The 4.0 pump is the same number as the 258 pump but with an "A" on the end. Does anyone know if they're interchangeable? The motor I'm buying is complete, so I'll probably switch to the serpentine belt settup. I've read that I'll need to use some kind of spacer to mount the 4.0 serpentine's harmonic balancer to the 258 crank.
The last issue that I can think of to tackle is the fuel pump. Since the 4.0 was built for fuel injection, it won't take a mechanical pump, so I'll have to switch to electric. That goes against my "Keep it simple stupid" philosophy, but I have no other choice. I'm thinking of using a Mr. Gasket Micro electric 4-7 PSI pump with no regulator, and mounting on the inside of the right rear bump stop extention to keep it level with the bottom of the gas tank. Does anyone on here have any experience with these pumps? Should I carry a spare so I don't get stranded???
I think I covered all the bases. Did I miss anything????
Thanks for any input!
David
I decided to pull the trigger on starting my stroker motor project. I'm picking up a good 1995 4.0 donor motor today or tomorrow, and over time I will pick up new Sealed Power dished pistons that should give me roughly 9.25 to 1 compression, getting the block bored either 30 or 60 over, and I'll be using the crank out of my 258 machined 10 under to clean it up.
My plan is to do a cheap but solid build using my 258 crank and rods, the 4.0 block and new pistons, and the stock 4.0 high output cam and lifters. I already have a killer 4.0 head that I'm currently using on my 258, but I also plan to continue using my HEI distributor and MC2100 carb instead of going the fuel injection rout that most do. Unless it shows signs of wear, I think I'll also be re-using the tru roller timing chan I already have in the 258. It only has 25k on it, so I expect to find it still in good shape. I guess I better check to make sure the 4.0 and the 258 take the same chain and gears?
What I've confirmed so far is that the bell housing bolt pattern is the same between the 258 and 4.0. The distributor will also fit. There is a little question on the motor mounts though. From what I gather, the later model 4.0's (TJ's maybe) require a little grinding on the block to get the CJ mounts to clear, but I don't know for sure what year in the 4.0 production that this change occurred. Any input on this would be welcome!
I also discovered that there's a slightly different part number for the oil pump. The 4.0 pump is the same number as the 258 pump but with an "A" on the end. Does anyone know if they're interchangeable? The motor I'm buying is complete, so I'll probably switch to the serpentine belt settup. I've read that I'll need to use some kind of spacer to mount the 4.0 serpentine's harmonic balancer to the 258 crank.
The last issue that I can think of to tackle is the fuel pump. Since the 4.0 was built for fuel injection, it won't take a mechanical pump, so I'll have to switch to electric. That goes against my "Keep it simple stupid" philosophy, but I have no other choice. I'm thinking of using a Mr. Gasket Micro electric 4-7 PSI pump with no regulator, and mounting on the inside of the right rear bump stop extention to keep it level with the bottom of the gas tank. Does anyone on here have any experience with these pumps? Should I carry a spare so I don't get stranded???
I think I covered all the bases. Did I miss anything????
Thanks for any input!
David