Home | Register | Login | Contact Us

 
Auto Math
Classifieds
Forum
Gallery
Games
Garage
Tech Articles
Utilites
 
FAQFAQ    SearchSearch    RegisterRegister    Log inLog in    Log in to check your private messagesLog in to check your private messages    Forum Subscriptions1/4 Mile Table 

rod side clearance
Goto page 1, 2  Next
 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Other - Engine Discussion
View previous topic :: View next topic  
Author Message
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Sat Nov 27, 2010 12:39 am    Post subject: rod side clearance Reply with quote

finally picked up my short block and already spotted a problem. the side clearance on the rods is .028-.038. my question is HOW MUCH of a problem is this ? my machinist had to do some grinding on the rods to get them to fit in the Olds and either he ground too much or the crank grinder took out too much on the sides. can this work or do i need to make my machinist eat a set of rods ?
_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
grslms51
Member


Joined: 30 Sep 2007
Posts: 56

1867.16 points



PostPosted: Sat Nov 27, 2010 12:20 pm    Post subject: Reply with quote

wow..seems like a lot...i used to run that much with aluminum rods,but not steel...going to be a lot of oil slinging from them,JMO.
Back to top
View user's profile Send private message
Paul P
Member


Joined: 15 Aug 2002
Posts: 2403
Location: Townsend, Mass.
81574.74 points


1971 Chevrolet Chevelle

PostPosted: Sat Nov 27, 2010 12:27 pm    Post subject: Reply with quote

I had the same issue with the 406 but only .026 max. It did reduce the cylinder temps on the ones that it was slinging oil on.If you can mix and match them to reduce it down to something in the .020's that would be better.
_________________
2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi

1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3209
Location: South Carolina
318129.23 points


1972 Chevrolet Nova

PostPosted: Sat Nov 27, 2010 12:50 pm    Post subject: Reply with quote

I wouldn't worry about it. Here's my logic. Oil has to pass through the bearing first which has 0.002" - 0.003" clearance before it gets to the rod side clearance gap. The bearing should be the metering device and not the rod side clearance. Another reason is years ago in the mini stock dirt track cars we ran the 2.3 Ford and one thing to do was run a small journal SBC rod in it for a cheap long rod to help with the high rpm's. I can't remember but it seems like the big end on the Chevy rod was like 0.080" or so narrower than the Ford rod and there weren't any problems with that so you should be fine. Looking around Speedtalk it seems like NASCAR has gone to piston guided rods (probably years ago I'm sure) in which case I would think they would have to open up the actual side clearance to do. Clay
_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
jeep_406
Member


Joined: 12 Sep 2002
Posts: 1661
Location: Tewksbury, Mass 01876
53123.48 points


1972 Chevrolet Nova

PostPosted: Sun Nov 28, 2010 2:48 am    Post subject: Reply with quote

The 406 Crank & Rod set I had in the Nova before the setup I now run had a lot of side clearance. As I remember it was either just under or over .03
Never had a problem with it. Ran it for 4 years shifting as high as 7 grand. When I took it apart the bearings looked fine. Don't remember the actual number of runs but it was well over 400 with about 15K worth of street driving.
Back to top
View user's profile Send private message Send e-mail
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Sun Nov 28, 2010 3:13 am    Post subject: Reply with quote

i finally got in touch with my machinist today. he said he was setting it up for .025 and thinks his guy mixed up the rods when he put it together. i have to take the short block back to him next week to fix it.

i did post this on three other boards and got some interesting replies. its just like any other un-proven topic. there are a handful of guys that say it wont work and another handful that say they have run more clearance than that with no issues. i have yet to find anyone out of a combined 1000+ views and over 40 replies that has experienced a failure due to excessive rod side clearance. now, i dont think its ideal and wouldnt do it on purpose but based on what ive been able to decipher from all this, i dont think its as much of a problem as some would have me believe.

_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Sun Nov 28, 2010 7:02 pm    Post subject: Reply with quote

Hear is good one to add to your library.

http://www.manleyperformance.com/dl/tech/rod-4340-ibeam.pdf

I wouldn't have a problem with .040"
Like it says final # to be determined by machinest.
Back to top
View user's profile Send private message
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Mon Nov 29, 2010 1:13 am    Post subject: Reply with quote

i decided to tear this thing down instead of taking it back to my machinist. long story short, he owes me 5 rods. the 5 he ground on. not only did they not need it but the surface after grinding is rough as a file. had he left them alone the side clearance would be .015.
_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Mon Nov 29, 2010 6:03 pm    Post subject: Reply with quote

That is totally messed up!!!!

What was his reason??
Back to top
View user's profile Send private message
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Tue Nov 30, 2010 1:08 am    Post subject: Reply with quote

ok after further inspection, i think one was already bad. it has a perfectly smooth taper to one side. the untouched rods are .940 wide this one is .935 at the center of the beam and .925 at the center of the cap. had to be bad already, the finish is too nice. the ones my machinist did look like sh!t. im not sure why he felt the need to cut them. only thing i can figure is that he was cutting them to fit an Olds journal instead of Chevy. he is picking up the rods and crank tomorrow to see for himself. pretty sure the only fix is for him to buy 4 new rods and i HOPE i can get the weird one replaced.
_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3209
Location: South Carolina
318129.23 points


1972 Chevrolet Nova

PostPosted: Tue Nov 30, 2010 8:53 pm    Post subject: Reply with quote

So I'm guessing he put them on a belt sander or something like that by hand? That sucks. I hate that happened to you, glad you caught it now. Good job on double checking everything. Clay
_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Tue Nov 30, 2010 10:33 pm    Post subject: Reply with quote

clay wrote:
Good job on double checking everything. Clay


No Crap!!!!!!!!!!!! or shyiat or what ever. !!! It really makes me sick to have to do it but you have to!! Evil or Very Mad
Back to top
View user's profile Send private message
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Fri Dec 03, 2010 2:27 am    Post subject: Reply with quote

yay!!! more fun stuff !!!!


this is what both #1 main bearing halves look like. bearing failure in one revolution. that has to be a record Evil or Very Mad .







it doesnt appear to have dug into the actual bearing just the Polydyn coating. crank and oil galleys were full of sh!t.

_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3209
Location: South Carolina
318129.23 points


1972 Chevrolet Nova

PostPosted: Fri Dec 03, 2010 11:36 am    Post subject: Reply with quote

Quote:
crank and oil galleys were full of sh!t.

That sucks. Anybody can make a mistake, but being careless gripes me BAD! Clay

_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Fri Dec 03, 2010 1:24 pm    Post subject: Reply with quote

WOW!!

Nice friend. Evil or Very Mad

Time to go to the car wash with $5 and blow the crap out. Rolling Eyes
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Other - Engine Discussion All times are GMT - 5 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum
Home | Contact Us | Automath | Cam Files | Dyno Search | Forum | Garage | Picture Gallery | Reaction Timer

Copyright 1997-2016 SMOKEmUP.com All rights reserved.
Advertising Info     Disclaimer     Privacy Policy