hey i've got a 99 f-150 with a 5.4L that has developed a rod knock latley and i was going to rebuild it and beef it up a little so i was looking at the manley website and they offer a 3 valve piston that has an offset piston pin, i know this reduces the side load on the pistons therefore reducing wear i was just going to check and see if anyone else had tried to put these pistons in the older blocks. the 6.5cc dish would also bump the compression ratio a little over the current 11cc dish pistons and with the longer strok in the 5.4 i think the offset pins would really help. any info is app.
anyone used 3 valve pistions in a 2 valve motor?
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BlackenedSVT
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Ehhhh, dont think thats a good idea. Is 2 of the valves even in the same positions as the 3valve engine? Meaning the valve cut outs might not even line up if you were to put it in a 2v motor.
That just doesn't seem like a good idea. Why not just get the CORRECT high compression pistons
That just doesn't seem like a good idea. Why not just get the CORRECT high compression pistons
You can use any 90.2 mm piston with standard compression height in a 2V. The 3V valve reliefs do not come into play with the 2V. The closest point the valve comes to the piston is along the upper surface of the ring land...that 10 mm radial flat area on the deck of the piston. No matter what size dish, that flat is constant.
The 3V's have valve reliefs that interrupt this flat area, but in a 2V, they don't give you any additional clearance. (No, the 3V intake valves are not in the same location as the 2V valves, relative to bore.)
All of the modular v8 pistons have offset pins. They just vary from ~.8 mm to ~1.3 mm. It's to alleviate piston slap. Your 3V 4.6L is a .8 mm offset and the 2001 2V 4.6L for example is 1.3 mm.
This offset makes it imperitive that you install your pistons in the correct orientation. There are "front of engine" indicators on these pistons. If you get them backward, you're gonna have problems.
I'm going to be insalling a 3V short block this winter. I'll let ya know how it turns out.
The 3V's have valve reliefs that interrupt this flat area, but in a 2V, they don't give you any additional clearance. (No, the 3V intake valves are not in the same location as the 2V valves, relative to bore.)
All of the modular v8 pistons have offset pins. They just vary from ~.8 mm to ~1.3 mm. It's to alleviate piston slap. Your 3V 4.6L is a .8 mm offset and the 2001 2V 4.6L for example is 1.3 mm.
This offset makes it imperitive that you install your pistons in the correct orientation. There are "front of engine" indicators on these pistons. If you get them backward, you're gonna have problems.
I'm going to be insalling a 3V short block this winter. I'll let ya know how it turns out.
01 steed, you wouldn't know the off set for the 99 5.4L? or where i may find that info out. manley add. say their 3v pistons are 1.2mm of set but no add. as to what the 2v pistons are i plan on calling them a little later today. However after a little bit more math i think even with the 11cc dish pistons i may end up at roughly 10.8:1 CR because of the longer stroke of my 5.4L not sure what the deck clearance is on the 5.4 but i used .035" for gasket thickness and deck clearance together which seems really close to me but i'm used to old SBC where there is as much as .050"+
For the '99 Lightning, the offset is 1.27 mm (1.15-1.39).
Your gasket thickness should be .038" itself if you're using a stock thickness. Add in the piston to deck clearance. I don't have that dimension, but I believe it's more than the .0118" of the 4.6L. Someone will chime in with that.
Your gasket thickness should be .038" itself if you're using a stock thickness. Add in the piston to deck clearance. I don't have that dimension, but I believe it's more than the .0118" of the 4.6L. Someone will chime in with that.
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