pros & cons.......

[LiquidBoats]

We are rebuilding a 96 2.5 EFI which has had work done to it before by someone who was supposed to know. Well...... it didn't make it to 15 hrs ( and to answer ahead of time: yes, break in was for first 10 hrs.......oil is HP @ 25:1 first 10, 32:1 after ) Head gasket blew on #6 (which is also the cylinder that was resleeved with a steel sleeve ) and # 3 top ring broke 1/2 inch away from pin which has scored the #3 cyl wall. Lots of questions here....... First and most important..... we want it to last ( recognizing of course that it is a HP motor ) The thought is to have the block resleeved and re NiCom'd on all 6. The next is that the rods as I understand it to be should be "top guided"....... which isn't the case. Any pros/cons here? The rods are the 625-5250's which I hear are good rods....... but, are they the best? I know changing them will require a piston change as well, but I have to buy 2 pistons as it is, and I have a set of good top guided rods already. Next, I don't know if the exhaust porting has been modified, but appearances don't really indicate it. I guess you could say that we are stepping in the middle of a " mystery history " motor. The heads are not the factory originals......the #6 piston isn't even close to the other 5 in terms of porting & wall thickness so we will have to determine their origins, cc's, etc. to see where we are at. Thats a next week project. In any event, the starting point will be the block, and any suggestions/tips will be appreciated.

[ImbadBob]

The bottom guided 5250s can be surface ground .050 off each side of crank end the piston end needs 4 groves & 2 holes to match the top guide rod the rod bolts are sometimes different. After grinding ,drilling, demag, deburr , and polishing . They need to be balanced. Had to do mine last winter. #6 check the head for flatness. Get 6 pistons the same & balance everything. Used is often unknown, I keep lookin' at the feed store but they still don't have seeds for a drag motor vine Oh well hope this helps alittle. Bob

[MERCMAN]

i would look for a nice set of newr pistons for your small rods , there are 2 sets of 5 on the board now for sale that are nice for 250.00 , then you could just find the last one somewhere , dont use them unless you have them pinned. email me when you get a chance jwsav@aol.com