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Full Flange #5 Main bearing not available.

5K views 7 replies 3 participants last post by  eschaider 
#1 ·
I talked to a guy over at King a few weeks ago and he said they no longer offer the main bearing set that has the fully flanged #5 bearing.
I need to get this figured out real soon. Both my engine builder and the guy at King said to us the XP coated bearings.
Wondering what everyone is doing for main bearings now ?
2005 4.6L aluminum 3L2E Nemack block
 
#4 · (Edited)
They have never made the fully flanged in XP series that I'm aware of. I use the SI series and make 1350whp and this engine has been in service for 4 years now, seems plenty adequate to me. However if you and your engine builder are dead set on the XP, forget the fully flanged deal and just run em.
 
#5 · (Edited)
Tony is right on both counts, Matt.

The fully flanged bearing set (for our engines) has never been offered by King. Moreover the only fully flanged upper from anyone is in the 5219 bearing set from King. Like Tony said you need to buy two sets of bearings, take the fully flanged upper out of the 5219 set and use it with a 5281 main bearing set flanged #5 lower.

The preferred bearing material for a supercharged engine has high embedability and conformability characteristics. The XP series bearings from King are tri-metal bearings with low embedability and conformability. The HP bearings from King have slight improvements made in the oil channel placement and geometry but are still made with SI bearing material notwithstanding their HP designation. High load tri-metal designs are very good for sustained high rpm, high load applications. The thin babbit layer and their diminished conformability make them a less attractive choice for supercharged applications. The sudden rise in engine torque and our abilities to hook this level of power up damages a try-metal bearing. It doesn't phase an SI bearing.

If it makes you feel any more comfortable the bearings used in Top Alcohol, Pro-Mod and Nitro cars are even softer material - they are babbit! The babbit bearing material is used on rods and mains because of - you guessed it, conformability and embedability

While your engine's build choices and decisions are certainly yours to make as you best see fit, I would highly recommend the SI material King bearings for both rods and mains. I would use the flanged upper shell for the #5 Main out of the King MB-5219SI main set to replace the non flanged #5 in Kings 5281 main set. Sadly the remainder of the bearings in the 5219 main set are throw aways. The good news is the two SI bearing sets will cost you essentially the same as the one HP bearing set and substantially less than a single XP bearing set.

Like the Bobby McFerrin's 1988 hit song Don't Worry be Happy, just get the SI bearings that Tony pointed you at from Summit, put them in and don't worry be happy - they will work like a champ.

BTW when you use a fully flanged upper and lower don't forget to set the crank end play. Install the main cap, lightly tighten the studs and back off the main stud nut just enough to allow the cap freedom of motion. Tighten up #3 main cap, put a dial indicator on the end of the crank. Use a large flat blade screw driver between #3 main cap and the crank counterweights to move the crank backward and forward until the thrust faces of the #5 bearing are flush with each other. Your end play should be between 0.005" and 0.012". Torque down all the mains including #5 and you're done. Don't forget to oil the rod and main journals. FWIW I like to put two drops of Prolong on each journal as insurance against a slow or no oil pressure build up at first start. Be careful with the Prolong. It doesn't take much to extend your ring seating by a thousand miles or so. The stuff is ultra slippery.

BTW the Ford spec on the crank end play is 0.130 ro 0.301mm or in the Imperial System 0.005" to 0.012".

Human body Organism Font Parallel Slope


Take your time be deliberate and you will be fine.

Ed
 
#6 ·
Tony is your car the black turbo car running low 8's in a vid on Jake's youtube channel? its an old vid.
Ok back to the bearing talk, I have no doubt about your experience and what you are saying, and yes 1350whp is a lot more then I'll be throwing down, but I think its fair to say I will be putting a lot more stress on the main bearings running the big Whipple in comparison to a turbo car. My engine builder is very good, his rep goes back a long way But he is not a mod motor guy. The nice thing is he is open minded and someone that will do whatever I tell him to, if I tell him i want a certain PTW with abc ring gap and use xyz bearings with such & such clearances he will do it. Only reason I started this thread was because I found it interesting that when I asked my engine builder and the tech at King "what series bearings should I go with?" si hp or xp? They both said the exact same thing, they said are you running a steel crank shaft? when I said yes billet they both said to use the xp. So that was the only reason I was looking for the full flange #5 upper in the xp series. For a side comparison I had also talked to Tim at MPR about this and he said to use the clevite 2259 H series, he doesn't do the full flange #5 upper, he uses a thrust. All that said I'm a simple guy & like to keep things simple, no need for a Rube Goldberg here. If the SI series has proven to hold up good in your motor at that power level then that is more than enough evidence for me to go ahead and use them. Tony I appreciate the input.
 
#7 ·
Ed to be honest after all this time since I first read about the #5 full flange upper in a thread from years back I think that was started by a guy named Rtusnake (not sure), I have seriously forgotten the reasons for going the full flange route instead of the traditional thrust bearing setup.
I really like your explanation on the high embedability and conformability characteristics of the SI bearing Vs the XP in a SC motor.
I'm sure my engine builder will very much appreciate the instructions and Ford service tech visual for the crank end play.
When I go to his shop its nothing but billet big block & LS stuff lined up front to back and of course he's was big on SBF pushrod motors that's how I know him from way back but not many guys build those anymore. So I'm the only mod motor in the place, I can't even begin to tell you about the amount of crap my crew gives me for sticking with this cobra for so long, another reason I'm hoping it eventually turns a decent number.
As always Ed thanks for the help.
 
#8 · (Edited)
Matt,

Just as a historical foot note, I believe the fully flanged #5 upper was something that Sean Hyland and John Mihovitz came up with to address a recurring thrust bearing failure with auto trans equipped engines. At the time the approach involved using a flanged lower from Federal Mogul for the engine, machining the #5 block saddle to accept the tang on the lower insert OD and then drilling an oiling hole at 12 o'clock to supply additional oil to the thrust face of the bearing.

The additional oil supply hole (in the thrust face of the bearing) was an attempt to eliminate the recurring thrust failures on the auto trans equipped engines. Additionally the primary oiling hole at the top of the bearing along with the oil channel in the face of the bearing had to be machined into the bearing insert. In later years transmission builders discovered how to reduce converter pressure to prevent the converter from driving the crankshaft forward against the #5 thrust bearing and destroying it.

The King bearing flanged #5 upper alternative was something I stumbled onto a number of years ago while rummaging through the King catalog looking for a particular bearing for our engines. I found the flanged #5 upper in the King 5219 bearing set — I couldn't believe my eyes! Even better the King bearing did not use a bearing tang to locate the insert in the block and it already had the proper oiling hole with a correctly positioned oil channel already in the bearing. The commercial availability of a fully flanged insert without the need to do any of the painstaking machining to make it out of a lower insert was like finding nirvana. I began to steer the guys on our site to the part number and the rest is sort of history.

I have a personal preference for fully flanged upper and lower thrust inserts. God knows there are thousands of Modmotors with the multi-piece #5 thrust that are successfully running out there. I just prefer the simplicity of the all in one fully flanged inserts for my engine builds.


Ed
 
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