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Are fancy piston coatings worth the $$$$? My new pistons are ordered and coming along, I have the option of sending them to the coating place for a moly skirt coating and a heat reflective top coating.......
I'd not worry about any heat-resist or heat-reflective coatings for these engines, they won't run hot enough or fast enough for them to be any help.
The graphite coating is useful (or not) - I'd be more inclined to have it for high-speed engines, but it can't hurt either. After all, the H802CP from Sealed Power has the graphite pads (or are they moly?) on the skirt for the later years, and they seem to work well for all years.
For more piston opinions, you may want to check out the archives at the "strokers" group - groups.yahoo.com/group/strokers. We beat things like this around all the time....
It looks like I just traded one of my spare 4.0L's (blown head gasket) for a late model 4.2 that's due to be rebuilt. So, I'll have a serpentine belt crank and rods for another stroker project for the MJ.
I met a guy with an extra 258 short block laying around his garage that he wanted to give me for free. Is it worth it for the crank and rods? Any thing to look for?
I spoke to Scot frey today and he can't get the Eagle rods any more, apparently some one bought all the 200 something rods at once . Did he tell you he had them in stock????
I bought sets of both the Eagle Sir and H-beam rods within the past year through Summit Racing - they were special ordered from Eagle and arrived in 10 days or so - I got the impression they were being manufactured to order but maybe they came out of stock?
If you don't want it, I'll take it. I could use the crank at least, I need a core to get offset ground to 4.000 for a project I've got in mind....
5-90
SeanP said:
I met a guy with an extra 258 short block laying around his garage that he wanted to give me for free. Is it worth it for the crank and rods? Any thing to look for?
I bought sets of both the Eagle Sir and H-beam rods within the past year through Summit Racing - they were special ordered from Eagle and arrived in 10 days or so - I got the impression they were being manufactured to order but maybe they came out of stock?
According to Mike at Accurate Power, Eagle have stopped making the SIR rods for the 4.0 and he's run out of stock for his stroker kits. You'd be lucky to find any at all now. If not, the alternatives are either to recondition your stock 4.0 rods and use them with custom forged pistons or to use AMC 258 rods with 4.0 pistons.
Mike said he was going to talk to his reps today (monday). I guess I might have to step up the H-beam rods, which are a whole lot more expensive, or just get some new stockers.
I have "zero" faith in reconditioned rods. That seems to be the weak spot in the 4.0, as I've seen too many rods go south right at the 200,000 to 250,000 miles range.
Mike said he was going to talk to his reps today (monday). I guess I might have to step up the H-beam rods, which are a whole lot more expensive, or just get some new stockers.
I have "zero" faith in reconditioned rods. That seems to be the weak spot in the 4.0, as I've seen too many rods go south right at the 200,000 to 250,000 miles range.
H-beams are made by Eagle as well, and they are about twice the price ($450). They are also .025 longer than stock, which means I'll have to modify my piston pin height if I want to keep my compression and quench as blueprinted.
I used the Zollner/Sealed Power pistons in my newest micromotor...my machinist specs them in budget roundy-round motors...says they wear very well because of the relatively high silicone content and the skirt coating.
My 2 cents is antiscuff coating is a great idea...especially if you use low silicone content pistons...I wonder what Ferrari uses in their 18,000+ RPM
Formula 1 motors???
I have "zero" faith in reconditioned rods. That seems to be the weak spot in the 4.0, as I've seen too many rods go south right at the 200,000 to 250,000 miles range.
Most engines go south well before 200-250k miles so I'd be very happy with rods that last that long. It's unusual for rods to break under "metal fatigue" though. They usually break either because the engine overheats, is overrevved, is hydrolocked (probably the commonest reason in the 4.0), or there are oiling problems.
If used rods have been X-rayed for cracks, magnafluxed, shotpeened, and had the rod beams polished, there's no reason why they shouldn't last a very long time especially in a low revving motor like the 4.0 (or stroker).
