My Mopar Performance short block

[Guitar Jones]

I'm happy to report is still in great shape after a year and a half of 7500 rpm passes on it. Although it has sat since the end of 2001 I raced it hard for the year and a half before that. Since a bad rod bearing did my 340 in I decided to pull the pan and check everything before I went racing again. All the bearings and the crank looked great. I replaced the rod bearings anyway since I was there but I'll let them stay in 2 or 3 years the next time.

One thing I can tell you if you mothball your engine for any length of time like that, consider pulling the pan to clean the crap out of it because man it was nasty looking in there. I probably should have changed the oil before I put it away.

 

[moper]

Glad to hear it's a good one..Sometimes all you read are the problem children..
In regard to longterm storage, the rocker arms/shafts should be backed off too, to seal the cylinders, and to let the springs rest in a "least damaging" position.

 

[AdamR]

I didnt know you were running a MP short block. Glad it worked out for you. Fastback340 didnt have very good luck with his.

 

[Buschi340]

Glad to hear it's a good one..Sometimes all you read are the problem children..
In regard to longterm storage, the rocker arms/shafts should be backed off too, to seal the cylinders, and to let the springs rest in a "least damaging" position.

good idea. never thought about it... :thumrigh:

 

[FASTBACK340]

I didnt know you were running a MP short block. Glad it worked out for you. Fastback340 didnt have very good luck with his.

Well.... I wouldn't totally blame the MP short block. The cam did disintergrate in 20 miles, but you know as well as I do, I assembled the damn thing. The combination of the 1.6 rockers, .509" cam, and milled heads raised hell with my pushrod geometry (or lack of....) This weekend I'm tearing it apart and sending her out to be freshened up. I'm also going with a cam in the .484" lift neighborhood with 1.5 Crane rollers.

I bet you guys can't wait to hear me *****-n-moan about building it again. :eye:

 

[Guitar Jones]

I used to have a very nice 340 +.030 with Ross pistons, Eagle H beam rods and floating pins. The block had good windage and oil control but when it spun a rod bearing and broke a rod two weeks from the end of the season and 3 weeks away from the Division finals I didn't have time to build another short block. I was in 2nd place at my home track and needed to get something together in a hurry.

I had the MP shortblock that next Tuesday and after mocking and measuring everything I disassembled it for machining, installing ARP rod bolts and getting a smaller cam because I was afraid to cut the valve reliefs any deeper than I already had. My son and me thrashed all week, I took off from work on Thursday and Friday and worked to 2 or 3 am in the morning every night. I had the engine back in the car, cam broke in, valves readjusted and oil changed by 4 pm that next Saturday when the race got rained out. I was ready to race though. So I went out that next Wednesday night for test and tune where the car ran 10.90, 10.89, 10.88.

I won the next weekend but still remained in second place in the points but I was ready to go to the finals. It was all kind of a waste though since I got pneumonia at the finals. I was sick as a dog with a fever of 105. Needless to say I went out first round.

Anyway for a $1000 I can't gripe about that short block, I had to go to some extrordinary measures and some really tight clearances for piston to head, (.028, valve .058 int / .086 exh, this was after I got an extra piston and cut it up to see how deep I could cut valve reliefs) to get my big Hughes cam in it but it works.

 

[THEWHITEZOMBIE]

Great to hear man,ive had my eye on one of them things for some time now,an u just made me want it more

 

[BadAssDodge]

im running a MP short block too, was gonna run a crate but didnt wanna go the magnum route, and wanted different heads/intake than the crate 360. Its a good motor for the price.

 

[FASTBACK340]

im running a MP short block too, was gonna run a crate but didnt wanna go the magnum route, and wanted different heads/intake than the crate 360. Its a good motor for the price.

That's kinda what steered me into a MP short block too; I wanted to use my 6bbl. set up, plus I had a set of ported X heads. This time I'll get it right. Just need a bucket of cash to make it happen. Again....

 

[duster340]

im running a MP short block too, was gonna run a crate but didnt wanna go the magnum route, and wanted different heads/intake than the crate 360. Its a good motor for the price.

That's kinda what steered me into a MP short block too; I wanted to use my 6bbl. set up, plus I had a set of ported X heads. This time I'll get it right. Just need a bucket of cash to make it happen. Again....

do you guys trust the X heads? here in sweden they have a bad reputaion for cracking in the floor of the exhaustports when used on hard running engines!