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Discussion Starter #1
bought a 521 stroker kit from CNC motorsports. has 4.3" stroke cast eagle crank, eagle forged Hbeam rods with ARP capscrew bolts, mahle flat tops. clevit 77 rod and main bearings.

tq specs for the eagle rod ARP capscrew bolts are 63ftlbs, also the recomended rod bolt stretch is .0059-.0063". now my tq wrench is a cheap one since its rarely used (ive only built 2 motors) but the 1/2" drive tq wrench is less than 1yr old from harbor freight. my dads rod bolt stretch gauge is from summit and is the summit brand, never used and less than 2 yrs old.

so heres the issue:
I took the free length of the rod bolt (out of the rod) with .200" preload on the rod bolt stretch gauge. I then zero'd the gauge out (yes the rod bolt dimple/holes were used and lined up). covered the rod bolts with ARP fastner lube and screwed them in by hand. I then used the tq wrench on them and tq'd them to the recomended 63 ftlbs. I then took the rod bolt stretch gauge and with a steady hand saw only .004-.005" on the gauge! I then proceded to tq the bolts till they reached the .006" mark on the gauge. I then checked this with the tq wrench and found that they were in the 80-110ftlbs range! how is this possible? is the tq wrench off that much?

Also each rod bolt used a different tq rating, some only needed 80, some needed 95, 100, 110ftlbs, and each bolt on the same rod got different tq ratings. This was so each bolt had a stretch of .006".

what should i do?

also i tested the rod bearing clearance with a plastigauge and with the 63ftlbs with the tq wrench i saw .0015" clearance which is alil tight. but now that ive increased the tq on th bolts to 80-110ftlbs how is this going to affect the bearing clearances?
 

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Check your rod journal with a mic and the bearing with a dial bore gauge and if your clearance is truly that tight I would take the crank to the machine shop to have it polished a little. I have had some bad luck with plastigauge so I no longer trust it. I would never use it on anything more than a stock rebuild even before the issues I have seen.
 

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Discussion Starter #3
I dnt have a dial bore gauge which is why i use the plastigauge. I think the clearances are alil tight but i want to figure out the clamping forces of the rod bolts before i worry about the clearances.

should i be seeing 80-110ftlbs on the rod bolts to get them to .006" stretch?
 

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Which style is the torque wrench the clicker kind or the beam style? I have not done the rod bolt stretch method so not sure how or why you are all over the board on torque. I would be worried about bearing clearance. Most shops will check all the clearances for you for a fair price if you are not equipped. If you need oversize bearings those are available to add some clearance if needed rather than the polishing I mentioned earlier.
 

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Discussion Starter #5
its a regualr clicker type tq wrench. im worried about both. i built a SBC 383 that i spun to 6500 with the same tq wrench about 7 months ago. im alil worried about why im all over the place with the readings. my bearing clearance is also a worry since im already tight at .0015" before i used the stretch gauge. prob is also that i dnt have a dial bore gauge so im dealing with the green plastigauge. i wanted around .002" on the bearings since it will mostly be street driven and not spun above 6000-6500 much ever
 

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Not sure if this will make a difference in the readings or not, but I vaguely recall the directions on my Eagle rods saying to torque them multiple cycles to meet the stretch requirements.

Tom
 

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Torque them down 3 times befor checking stretch, also I know I still ended torqueing them a little tighter after this about 70-72, but before doing them 3x's it took a lot more torque. You should probably get .001 looser bearings.
 

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Discussion Starter #8
thanks guys. i figured it out. I ended up retorqueing them 3-4 times and ended up at about 70ftlbs on every bolt. got me about .0055-.006" stretch on each bolt. i also had to add a stiff spring to the rod bolt stretch gauge to get it to stay on the rod by itself.

just a quick question, i got the bottom buttoned up and installed the cam its a lunati 61605. I put on the cam retainer plate on but i dnt know the tq settings on those tiny little bolts. I googled it but i see "front cover" but is it around 8-10ftlbs? also when i install the cam and the timing gear (cloyes double roller) im deleting the original double peice fuel pump eccentric, so do i just bolt it together and not worry about the cam thrust? how do i check the cam thrust? using a ARP 3/8" cam bolt kit as well and from what ive heard i should ditch the ARP washer and run the thicker stock washer?

i checked the bearing clearances and its still around .0015
 

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Discussion Starter #9
also wat about the waterpum and timing cover tq specs? thanks guys
 

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I dnt have a dial bore gauge which is why i use the plastigauge. I think the clearances are alil tight but i want to figure out the clamping forces of the rod bolts before i worry about the clearances.

should i be seeing 80-110ftlbs on the rod bolts to get them to .006" stretch?

On my Arp 2000 bolts was 90 lbs....it all depends on bolt length and lube type.

I also threw the stretch gauge in the garbage...for real. OD micrometer is the safest bet.
 

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i would be more concerned with the tight rod bearing clearances. those Eagle cast 4.3 cranks came a little fat on the rods and the mains, you can only polish 1/2 thou, i would look at +1 bearings
 

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Discussion Starter #13
is .0015" too tight for a street motor? i thought that .0015 was the min you could run if the RPMs are kept below say 6000-6500.

i wish they told me they come alil fat bc i bought the complete kit from CNCmotorsports and paid good money for this kit. i dnt think they would take it back tho since ive already got the motor assembled.

also i installed the cam/timing chain and i had some isses with the 3/8" ARP bolt kit, first they said not to use the stock washer bc they didnt know what material it was, and stated that the ARP washer was a stronger material and was flat ground, they said tq the bolt to 40ftlbs. I test fit the timing gear with bolt and the bolt bottomed out before there was tension on the ARP washer! (this is without the fuel pump eccentric that was on the stock motor) I then tried the stock washer and it worked, so i also test fitted the stock fuel pump eccentric with the ARP washer which worked bc it was basically the same thickness as the stock washer. But i said to hell with it and put the fuel pump eccentric on with the stock washer and buttoned it all up with ARP moly and red locktite.

I installed the timing cover/waterpump (why does ford need so many gaskets! 3 gaskets for the timing cover/waterpump? geez) i tq'd all that to 20ftlbs with arp fastners and moly lube. I went to install the balancer and realized my SBC/BBC balancer installer doesnt fit the ford! can i just bang it on gently or use the balancer bolt? my friend has a bunch of stangs with 302s and he has a balancer install tool but will it work on the 460?
 

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Just get some .001 looser bearings, probably cost you 60 bucks and if you want you can use the looser bearing on one half of the rod and set your clearance up at .002 or.0025 if you use both sides. .002 would be real good on a street motor
 

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Discussion Starter #15
got a part #? im running clevitt 77s now. wish i woulda known i already bolted the oil pump in and pickup!
 

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Discussion Starter #17
Just get some .001 looser bearings, probably cost you 60 bucks and if you want you can use the looser bearing on one half of the rod and set your clearance up at .002 or.0025 if you use both sides. .002 would be real good on a street motor
http://www.summitracing.com/parts/CLE-CB743P1/
would these be the ones i need? and i could run them on only one side to create a .002" clearance correct? so i would only have to purchase 4 boxes so that would be 8 bearings for the outer caps?
 

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Discussion Starter #18
my dad brought up a good point... if I only put the .001 undersize bearings on the outer rod bearing cap it will give me .0005" more cleranance so basically i would have .002" clearance with the original .0015" + .0005 = .002". But would it matter that only one bearing is slightly undersized pushing the crank offset? or wearing on the bearings differently due to bearings being different sizes?
 

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Yes it will be fine to just use half the bearing if you want .002 clearance. Some people dont think it sounds right but most engine builders do it.
 

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Discussion Starter #20
ok thanks! or should i just go for the .001 undersize and just get the .002-.0025" clearance? i plan to run her hard and maybe a small hit of NOS, also running a HV pump
 
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