Rod Side Clearance?

[67428GT500]

I just got the short block assembled and the rods torqued. This is on a 428 with a factory 3.98 crank and Scat H beam rods, JE pistons.  Through the search feature I found a commentary from Barry Robotnic that he had some with as little as .010 that ran well and long term with no issues. I really don't want to tear this back down.  Any reason for alarm?  I have perfect bearing clearances at .0025.


                                                                                        -Keith

[blykins]

How much do you have?

[My427stang]

I shoot for .020+, but if you are saying yours are .010, it may be fine, how are you measuring?  I usually deburr the rods and pair them up for width to come up with something the same on each pair, then I measure the crank and do a quick recheck when assembled with a feeler gauge. 

If you are trying to jam in a .010 feeler gauge with an oiled bearing pair, you may have more than you think anyway.

I likely wouldn't deliver an FE at .010, but my hunch is you'll be OK

[67428GT500]

I have between 10-13 depending on journal. I also used Royal Purple assembly lube on everything except the cylinder walls which I used Marvel Mystery Oil per suggestion from Mahle.

                                                                                               -Keith

[My427stang]

Prey them over good (without going crazy) and see what you see.

Probably will live, live and learn though, much easier to pair them up and see what you have before they go on the pistons.  Sometimes you have a little edge, etc that you can quickly handle, sometimes you cut them

[blykins]

I have ran .012” a few times, you’ll most likely be ok.

If that MMO is slick, it has no right to be anywhere close to a cylinder wall.  Good old mineral engine oil is the best for cylinder walls, and not at liberal amounts at that.  The decades of dunking pistons in tubs of oil are long gone.

[WConley]

I have ran .012” a few times, you’ll most likely be ok.

If that MMO is slick, it has no right to be anywhere close to a cylinder wall.  Good old mineral engine oil is the best for cylinder walls, and not at liberal amounts at that.  The decades of dunking pistons in tubs of oil are long gone.

Agreed!  Conventional oil is what you need for a new set of rings on an iron block.  The added lubrication of synthetics or special oils works against you during break-in.

[Heo]

My Mahle Piston /rings They recomend straight 10 non detergent oil for
AKA known as air compressor oil

[My427stang]

There is absolutely nothing wrong with what he used, some guys install dry, some use oil, MMO is just thinned oil with dye and detergent, thin, clean and fine for that, however certainly no special sauce either.

[67428GT500]

It's a very thin mineral oil.  JE pistons also recommends it. I have always used regular non-detergent oil.  I can definitely feel the difference. Mahle also supplied standard tension oil rails and expanders with this ring set.
As for the Scat Rods. I have never had an issue with side clearances. The other engine with Ford rods was .020- .024. I have always used the feeler gauge to take up the slack torquing the rods.
These are at 65LB.   I had the machinist check the small and big end for size and mag the new rods while balancing the bottom end. I made the mother of all F-ups by presuming the side clearances were checked. 
The rails and expander seem to have a lot more tension than the speed pro set I used in the last motor.  After using the Ford performance/TRW 428 pistons the lack required skirt clearances was a surprise too.
JE recommends .0035. The old TRW was .006.
                                                                           -Keith

[67xr7cat]

I'd check the side clearance without the bearings see if it changes. If it does the bearings are hitting the radius on the crank. If not, take out four rods and get .010" taken off the side. You may get away with what you have, but it is marginal.

.0035" for those JE pistons is a bit tight. The spec says " 4.000 to 4.200" bore .0035 to .0045" min. clearance". You piston diameter is a lot closer to the high side. For that piston you really want about .0045" - .005".  At .0035" you may scuff the pistons.

[67428GT500]

This is the sheet from the pistons. They are closer to .004. However with the old FE factory 428 pistons they were .006-.009. With .006 the slug almost drops in the hole..

[67428GT500]

I moved two rods. I wound up with about .013 across the board.  I feel relatively comfortable with that. I was careful of the radius clearance side.  No one wants to dig out double spirolocs.  Two swaps got me there. #1 and 5 are at .018. The OE rods were at .024.
                                                                                           -Keith

[67xr7cat]

Are your pistons 4032 or 2618 Material. Those numbers are for a 4032 material which would be their "SRP" piston line.

[67428GT500]

They are SRP/JE.