b20 vtec build: are my rod bearings too tight?
10-19-2008, 01:53 PM
#1
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b20 vtec build: are my rod bearings too tight?
using acl bearings, polished/balanced b20 crank, and forged rods (possibly eagles?) with 3/8" arp rod bolts torqued to 26 ft/lbs.
i installed the crank and torqued down the mains and i could spin it by hand. i installed all the pistons and rods onto the crank but did not torque them to spec and i could still spin the motor without much effort using a wrench. as soon as i torqued the rod bearings down the motor was IMPOSSIBLE to turn. so i loosen them and tighten just one. although i can still turn it, much harder to spin. is this normal?
note-i plastigauged all of the rod bearings and got ~.0012-.0015 in on all of them.
i installed the crank and torqued down the mains and i could spin it by hand. i installed all the pistons and rods onto the crank but did not torque them to spec and i could still spin the motor without much effort using a wrench. as soon as i torqued the rod bearings down the motor was IMPOSSIBLE to turn. so i loosen them and tighten just one. although i can still turn it, much harder to spin. is this normal?
note-i plastigauged all of the rod bearings and got ~.0012-.0015 in on all of them.
10-19-2008, 02:21 PM
#3
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Re: b20 vtec build: are my rod bearings too tight? (be18see1)
right, i dont know what rods they are. i was told eagles when i bought them, but the shop that i went through for my machine work said that they arent. i can check the rod to crank clearance with a feeler gauge, right? is crank thrust clearance the same as end play? i could just look for this in my helms but its on my pc and takes 15 minutes to finally scroll to where i want to be. thanks!
10-19-2008, 03:16 PM
#5
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check to see if your mains and girdle are turned installed and turned correctly. This happened to me once and it wouldn't turn because in haste I turned the girdle upsidedown lol.
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10-19-2008, 06:44 PM
#8
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Re: (DonF)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF »</TD></TR><TR><TD CLASS="quote">I am guessing used rods. Twist, bend, out of round. </TD></TR></TABLE>
supposedly the shop sized the rods to make sure they were all within spec.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF »</TD></TR><TR><TD CLASS="quote">43 for a real measured bolt, 28 for a socket size. He is lost.</TD></TR></TABLE>
what do you mean by this? i know a bolt stretch gauge would be optimal over simply torquing them to spec, but i dont have one.
supposedly the shop sized the rods to make sure they were all within spec.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF »</TD></TR><TR><TD CLASS="quote">43 for a real measured bolt, 28 for a socket size. He is lost.</TD></TR></TABLE>
what do you mean by this? i know a bolt stretch gauge would be optimal over simply torquing them to spec, but i dont have one.
10-19-2008, 06:52 PM
#9
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Re: (be18see1)
if i simply had bearings that were too tight, would i experience this same problem? ive been skeptical about the plastigauge thing, simply bc theres no way to double check.
10-19-2008, 10:41 PM
#10
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Re: (be18see1)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by be18see1 »</TD></TR><TR><TD CLASS="quote">if i simply had bearings that were too tight, would i experience this same problem? ive been skeptical about the plastigauge thing, simply bc theres no way to double check.</TD></TR></TABLE>
did you ever take the unamed rods to get inspected by a machine shop to check the roundness of the big end, ? paltigauge only work in checking the clearance in the spot you place the strip. you could have enough clearance in one spot on the crank, but not the other spots in the 360 degrees.
did you ever take the unamed rods to get inspected by a machine shop to check the roundness of the big end, ? paltigauge only work in checking the clearance in the spot you place the strip. you could have enough clearance in one spot on the crank, but not the other spots in the 360 degrees.
10-20-2008, 04:14 AM
#11
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Re: (projectTeG)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by projectTeG »</TD></TR><TR><TD CLASS="quote">
did you ever take the unamed rods to get inspected by a machine shop to check the roundness of the big end, ? paltigauge only work in checking the clearance in the spot you place the strip. you could have enough clearance in one spot on the crank, but not the other spots in the 360 degrees.
</TD></TR></TABLE>
like i said, i thought that they honed them. im going to pull them out and take them up to my uncles. he has a mic that goes to .00005". when i got the rods back, i was told that they had been honed at both the big and small ends. they all had the caps on and were torqued down. i thought it was odd that on a couple of them i could actually feel a lip where the cap met the rod. it wasnt huge, but i could feel it. they also were not matched correctly when i looked at the numbers on the cap and rod. i left them as is bc i figured whoever machined them hadnt looked to match them first.
did you ever take the unamed rods to get inspected by a machine shop to check the roundness of the big end, ? paltigauge only work in checking the clearance in the spot you place the strip. you could have enough clearance in one spot on the crank, but not the other spots in the 360 degrees.
</TD></TR></TABLE>
like i said, i thought that they honed them. im going to pull them out and take them up to my uncles. he has a mic that goes to .00005". when i got the rods back, i was told that they had been honed at both the big and small ends. they all had the caps on and were torqued down. i thought it was odd that on a couple of them i could actually feel a lip where the cap met the rod. it wasnt huge, but i could feel it. they also were not matched correctly when i looked at the numbers on the cap and rod. i left them as is bc i figured whoever machined them hadnt looked to match them first.
10-20-2008, 11:59 AM
#13
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Re: (popwars123)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by popwars123 »</TD></TR><TR><TD CLASS="quote">if there were ever different rod bolts put in it will put the rod out of wack unless you get them conditioned at the machine shop</TD></TR></TABLE>
and i did.
and i did.
10-20-2008, 01:25 PM
#14
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Re: (be18see1)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by be18see1 »</TD></TR><TR><TD CLASS="quote">
like i said, i thought that they honed them. im going to pull them out and take them up to my uncles. he has a mic that goes to .00005". when i got the rods back, i was told that they had been honed at both the big and small ends. they all had the caps on and were torqued down. i thought it was odd that on a couple of them i could actually feel a lip where the cap met the rod. it wasnt huge, but i could feel it. they also were not matched correctly when i looked at the numbers on the cap and rod. i left them as is bc i figured whoever machined them hadnt looked to match them first.</TD></TR></TABLE>
That is your problem, there is no lip. Is the bolt a real 3/8 with a7/16 12 point socket ? or a 5/16 bolt with a 3/8 12 point socket, it would be nice to know.
like i said, i thought that they honed them. im going to pull them out and take them up to my uncles. he has a mic that goes to .00005". when i got the rods back, i was told that they had been honed at both the big and small ends. they all had the caps on and were torqued down. i thought it was odd that on a couple of them i could actually feel a lip where the cap met the rod. it wasnt huge, but i could feel it. they also were not matched correctly when i looked at the numbers on the cap and rod. i left them as is bc i figured whoever machined them hadnt looked to match them first.</TD></TR></TABLE>
That is your problem, there is no lip. Is the bolt a real 3/8 with a7/16 12 point socket ? or a 5/16 bolt with a 3/8 12 point socket, it would be nice to know.
10-20-2008, 01:57 PM
#15
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Re: (DonF)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF »</TD></TR><TR><TD CLASS="quote">
That is your problem, there is no lip. Is the bolt a real 3/8 with a7/16 12 point socket ? or a 5/16 bolt with a 3/8 12 point socket, it would be nice to know.</TD></TR></TABLE>
ah. it is a 3/8" 12 point socket. im sorry for the confusion. im going to see if maybe the shop just got the caps and rods out of order and try to flip them around and see what i get. this is such a stupid problem to have. i overpaid so much for the machine work too.
That is your problem, there is no lip. Is the bolt a real 3/8 with a7/16 12 point socket ? or a 5/16 bolt with a 3/8 12 point socket, it would be nice to know.</TD></TR></TABLE>
ah. it is a 3/8" 12 point socket. im sorry for the confusion. im going to see if maybe the shop just got the caps and rods out of order and try to flip them around and see what i get. this is such a stupid problem to have. i overpaid so much for the machine work too.
10-20-2008, 03:48 PM
#17
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Re: (neogenesis2004)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by neogenesis2004 »</TD></TR><TR><TD CLASS="quote">Are you sure you didn't reassemble them with the cap on backward?</TD></TR></TABLE>
This is the same thing I have been saying, but no one listens to me anyway.
This is the same thing I have been saying, but no one listens to me anyway.
11-08-2008, 05:52 AM
#19
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Re: (be18see1)
bump bc i still cant figure it out. i noticed that i received the rods back with the caps mixed up and the rod bolts torqued down. i assumed that they had just honed them with the wrong caps bc theyre idiots so recently i tried to match the caps with their original rods but it didnt change anything. i guess im going to pull them out and take them to a shop and have them completely inspect the rod. i still dont even know what type of rods they are. each rod and cap has a matching number, for example 27 on the top and 27 on the bottom, and each has "4C" on the rod too. is this supposed to indicate bearing size?
11-09-2008, 09:47 AM
#22
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Re: (be18see1)
A good place to start is...
Take the rods to a decent machine shop with a new set of rod bolts. Have the machine shop resize the rods using the new rod bolts. Have the rods checked for twist, and length. If they show any measurable twist or bend, DO NOT REUSE. If they are off on length, the resizing process can be used to shorten the longer rods. Have them checked for balance after they are resized too.
Make sure you install the matching caps and rods BEFORE you have them resized.
Take the rods to a decent machine shop with a new set of rod bolts. Have the machine shop resize the rods using the new rod bolts. Have the rods checked for twist, and length. If they show any measurable twist or bend, DO NOT REUSE. If they are off on length, the resizing process can be used to shorten the longer rods. Have them checked for balance after they are resized too.
Make sure you install the matching caps and rods BEFORE you have them resized.
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