[mach1]

Hi,

I'm currently rebuilding a 351C and ran into a bit of a snag.

Here's my situation. The block was sent to the machine shop, they bought all ARP fasteners (main bolts, rod bolts, etc.) and did all the machining. I then got the engine back and began assembling it. Now I was about to seal up the bottom end with the oil pan, then I thought "windage tray", only problem is, I have main bolts, not studs. I emailed ARP & they confirmed what I've been reading here that I cannot swap out the bolts for studs without sending the block back for align boring. Since the engine is already partially assembled & painted, that really isn't an option for me.

Obviously I can just scrap the windage tray idea entirely, but I'm here now, so I figure why not install one if I can.

What do you guys think? What are my options here?

Thanks!

[Guy Hiltz]

Was the block align honed ??
If so,you could probably just switch the bolts for studs,any difference may be minor enough that it wouldnt matter.Maybe Carl will post his opinion on this.Or just shell out the bucks to have studs installed and get the mains align honed.
Or for the little difference a windage tray would make,just run it "as is".
But if you want to do things 100 % correct and have your heart set on a windage tray,get the studs installed and have the mains align honed.
Or is an oil pan available for the 351 C that has a built in windage tray,like the Moroso one I have in my BBC ??
Guy

[oldbogie]

Originally Posted by mach1

Hi,

I'm currently rebuilding a 351C and ran into a bit of a snag.

Here's my situation. The block was sent to the machine shop, they bought all ARP fasteners (main bolts, rod bolts, etc.) and did all the machining. I then got the engine back and began assembling it. Now I was about to seal up the bottom end with the oil pan, then I thought "windage tray", only problem is, I have main bolts, not studs. I emailed ARP & they confirmed what I've been reading here that I cannot swap out the bolts for studs without sending the block back for align boring. Since the engine is already partially assembled & painted, that really isn't an option for me.

Obviously I can just scrap the windage tray idea entirely, but I'm here now, so I figure why not install one if I can.

What do you guys think? What are my options here?

Thanks!

You more likely, than not, can get away with swapping the bolts for studs. The fasteners do not locate the caps, or at least shouldn't. Properly done the caps were located in the cap relief (step) of the block. The relief indexes the caps side to side and the flatness of the bottom of the broach and the bottom of the cap establish front to rear tip, not the bolts. Anybody that tries to use the bolts to hold lateral and vertical alignment of parts, doesn't know diddly about bolts. Though the manufacturers have tried this trick with rod bolts for years, that of using a body fit to align the upper and lower halves. It's OK on the street, but when you start pumping up the power and revs you start finding signs that the cap and shank are squirming around. Race engines used dowels to hold alignment and the new fashion even at the OEM is to use a cracked cap so that the features of the failure zone interlock and keep the parts from moving around. That relieves the bolts from a job they never did well and reduces their efforts to simply applying clamping force which is the only thing their good at. Bolts do not like bending moments applied to them, it's a sure way to discover their structural limits real fast.

The thing you need to be careful of is keeping the location and direction the caps the same as they are currently installed. That is mark them 1-2-3-4-5 and which way is the front, often caps come with a cast or engraved arrow for that purpose, if lacking use a dab of paint or permanent marker. Same goes for the bearing inserts, make sure they stay with the cap you found them in. Many cheepo/weepo shops put in oversize bearings intended for an undersize crank, then they hone bore the bearing for alignment and finish size. Not a bad technique, but precludes switching or replacing the insets without rehoning them.

This shouldn't be a problem, otherwise you could never pull the crank for bearing inspection and put it back together, parish the though you mixed those "locater" bolts, and this is done all the time on competition engines without encountering problems that disturb the align boring.

Bogie

[woodz428]

I'd just pull the bolts out and install the new studs. I can't imagine it making ANY difference. The same can't be said for rod bolts, but they are a loose press fit. The mains are just threaded, the fastener company is just just covering themselves....in case. They don't know who is calling and their capabilities. You should only need to swap out the center 3. I would, however loosen all and re-torque in sequence with the new hardware.
www.gearheadcity.com

[SnottyAust]

Did the same myself once on a fresh block. Swapped out the bolts for studs without a prob.

Besides checking clearances after installing studs, put the caps on without the bearings and run your fingernail over the cap to block joining line checking for any edge sticking out. Should be dead flat and probably will be if it was before.

[mach1]

Thanks for all the replies.
To answer some questions; Guy- the block was not align honed. The machine shop called me after they inspected the motor & told me that the engine was in good condition & it wasn't required, if I wanted them to do it, they would, but suggested I save the money for something else. When I assembled the motor, I double checked everything with plastigage & it was all spot on.

I also had the same thought as to the oil pan with a built in windage tray, however I wasn't able to find one for this motor.

I have to agree with all of you. I can't see it making any difference at all, but I'm no expert so thats why I wanted other people's opinion. The main caps are exactly like Bogie describes, they sit into a relief in the block, the bolts don't have anything to do with the alignment of the cap. Bogie is also correct in that the caps are all marked 1 thru 5 with an arrow pointing to the front of the motor.

I feel a lot better about this now.
Thanks again to everyone who took the time to respond, I really appreciate it!

[4 Jaw Chuck]

You don't need a windage tray, the factory style ones are junk anyway. You would be better off saving your cash for other items.

Save your money.