[crustysarge]

I have a 72 YH 455 block that I have had for 22 years under my bench and recently decided to build it up. Stroker kit with forged Eagle crank. This weekend I set up ARP studs, stock main caps, FM bearings and the clearances were:

#1 .0015
#2 .0015
#3 .0010
#4 .0018
#5 .0018 (Rear)

I set up the crank and torqued the studs to 110 and 140 on the rear. Crank would turn with all installed but #3, just too tight.

Time for a line hone? I had the shop do a deck and bore/hone but held off on the line hone until I could check personally

[cdrookie]

ya, those clearances are too tight

[cdrookie]

take the bearings out and remeasure to see if they're at factory specs also

[Tom Vaught]

Try a different brand of bearings too.

Tom Vaught

[taff2]

Try it again but torque the studs to 85 lb and 100 lb,studs pull differently on the caps compared to bolts and you may be distorting the bearing bores a bit. You may also still be able to pick up a set of 1x bearings(FedMogul used to make them but discontinued them) and use these to adjust your clearances.

[stimpy]

if your going from bolts to studs you should have it aligned bored anyways to make sure everything is in alignment .

[crustysarge]

I was using the torque rating provided by ARP that came with the studs....You know how that goes...

[Cliff R]

If there were clearance at #3 it would turn fine when the cap was torqued down. Did it leave "witness" marks on the bearing?

Bottom line is that you must have some oil clearance on all the bearings, and the crank must turn freely when all caps are torqued down. I doubt if the torque applied to the bolts or studs has any effect on the bearing clearances. Still wouldn't hurt to go back thru all the caps and re-torque, starting with the thrust bearing, go to #1, then 2, 3, and finish with #5. Turn the crank after each one is tightened, and if it starts getting to tight to turn by hand, stop at that bearing and investigate.

If #3 is the only one giving trouble(s), just a tad too tight and well centered, an oversize bearing might be just enough to avoid line honing the block. If the witness marks show the tight spot all in one direction, most likely you are going to have to line-hone the block to straighten things up some.....Cliff

[Mr. P-Body]

Considering it's a forged steel crankshaft, it COULD be "warped". Yes, it happens (regardless of "brand"). A forging should ALWAYS be checked for straightness. Assuring the journals are correct is also necessary.

We've found installing studs has virtually no affect on the straightness of the housing bores. Unlike the Chevy/Ford blocks, the locating dowels do a wonderful job. By all means, MEASURE. If it's "on-size, round and straight" (literally), no need for additional work.

We HAVE seen a significant number of '72-'75 455 blocks with main tunnel "issues". It sometimes shows up with the cam bearings, as well.

Recommend .003" for all the mains, MAYBE .0035" on the rear (not a biggie in a street engine).

Just touching the bases...

Jim

[Half-Inch Stud]

Try this: Populate #1, #2, #4, #5 & TQ: dial-indicator on the #3 Journal for Rich-man's Vee-Blocking the Crank.

Seems the #3 Bearing shells are numerically tight. Could perform a FINE hone of the bearings if you have the fine stones. One trick is to put a sacrificial Shell in the Lower if all you want to hone is the Upper. vis-versa.

Playing tricks: I've seen a corrosion ridge form on the Main Saddles that is worth using a blade-scrape. Keeps the Bearing backside on shiny iron.

Finally: reading the "witness marks": Pinch evidence at parting (Cap-Dowel Index) versus score across Bearing Saddle (too tight).

assumption: Block history is clean on "No spun Mains"

[superdutybob]

What is your crank end play when all torqued? Are you sure its not dragging on a thrust face?

[Brent Flynn]

Originally Posted by stimpy

if your going from bolts to studs you should have it aligned bored anyways to make sure everything is in alignment .

is this necessary? if it was ok before, why would it change goin to studs instead of the factory bolts? i was thinkin about studding the mains in my engine(455) that im in the process of putting back together...

[performerrpm]

Originally Posted by Brent Flynn

is this necessary? if it was ok before, why would it change goin to studs instead of the factory bolts? i was thinkin about studding the mains in my engine(455) that im in the process of putting back together...

i was actually thinking about this on my 455 too!!! hope i can do it without a line hone

[455Grandville]

Originally Posted by stimpy

if your going from bolts to studs you should have it aligned bored anyways to make sure everything is in alignment .

line hone w/ stock caps IMO

[crustysarge]

I have not had time to look at it since Sunday but when I put the crank in I did one cap at a time and the only one that "drags" is #3, damn near impossible to turn. The bearing shell showed some scuffing on the upper half on 3 and some on 2. I swapped some shells around without checking each one for thickness and the problem remained on #3. Problem is I got distracted by some cheap wine and forgot which bearing shell was which when I started...

I don't know history of block as I got it from someone 20+ years ago but the crank was with it and looked OK, BUT, who knows if that crank is from this block? Hell, who knows if these caps are from this block for that matter?

I am going to run it down to the shop today and let him check it out and hone if need be as well check the crank for me. It is a new stroker kit from Pontiac vendor.

[crustysarge]

Checked at lunch: I have .004 on the thrust. I put the crank in with just the front and rear main lower halves (poor man's V block...) but got no consistent readings so don't think I'll rely on that. Off to the shop.

[HWYSTR455]

Originally Posted by Mr. P-Body

Considering it's a forged steel crankshaft, it COULD be "warped". Yes, it happens (regardless of "brand"). A forging should ALWAYS be checked for straightness. Assuring the journals are correct is also necessary.

We've found installing studs has virtually no affect on the straightness of the housing bores. Unlike the Chevy/Ford blocks, the locating dowels do a wonderful job. By all means, MEASURE. If it's "on-size, round and straight" (literally), no need for additional work.

We HAVE seen a significant number of '72-'75 455 blocks with main tunnel "issues". It sometimes shows up with the cam bearings, as well.

Recommend .003" for all the mains, MAYBE .0035" on the rear (not a biggie in a street engine).

Just touching the bases...

Jim

Almost verbatim what I would say. Only thing I would add is if you're not sure of the history, you should have the block at the machine shop checking main saddle alignment, deck straightness, deck finish, etc, period. Why toss a fresh rotating assembly in an unknown block?

.

[hurryinhoosier62]

crustysarge,

After having align bored several thousand blocks, I would reccomend align honing first.
Sometimes, as little as .0002 can cause misalignment severe enough to prevent a crank
from turning freely.

Jim,

.003-.0035 clearence on a street engine? I have always used the "2/2" formula same
as Ken Crocie and other Pontiac builders. Additionally, I always "mic" my bearings BEFORE beginning assembly NO MATTER what type of engine I'm building.

[crustysarge]

Follow up on this. Shop found the main journals were out of round and tried to hone but no luck, had to bore. Machined the caps and bored to stock specs. Eagle forged crank was still not right. I had tried to check it while sitting on the #1 and #5 lower bearings as well as #2 and #4. My readings showed #2 and #4 out of round, by as much as .004 but I was not sure. Today the shop called and said they checked and sure enough found what I had. I did not tell them I measured so they were honest about it.

The old Italian machinst who has worked there for 42 years expressed his thoughts about my new Forged Eagle crank, "Merda Cinese" which means Chinese S#!t... he said it was out of round, poorly ground and that I was fool if I thought I could run it at 500hp levels the way it was. They polished/ground it to proper specs and said it spins freely now and clearances are around .002. I will go down later this week or next to check it out.

Pretty sad I have to work a new crank like that just to get it within normal specs...

[Half-Inch Stud]

"""""The bearing shell showed some scuffing on the upper half on 3 and some on 2. """"""

I got a bad bad vibe from that sentence; me thinks you got a split #2 Main: Mag-Flux inspect to prove it's not cracked.