-
FE TALK
(
http://www.clubcobra.com/forums/fe-talk/)
| wrench87 |
08-19-2010 11:42 AM |
fe 4.25 crank and h beam rod question
i have a steel 4.25 fe crank with the eagle h beam chevy rods , the crank was not right and had to be cut. i wanted to know what is acceptable for rod clearance?
|
| blykins |
08-19-2010 12:18 PM |
Rod bearing clearance or rod side/side clearance?
|
| wrench87 |
08-19-2010 01:05 PM |
sorry, i wanted to know what is acceptable side clearance?.
|
| blykins |
08-19-2010 02:04 PM |
I like to see about .016-.020, but I think the spec is .010-.020. However, if I were building one and it had .010, I'd have them milled a little. It's one of those things where too much is better than not enough.
How much you got?
|
| RICK LAKE |
08-19-2010 02:30 PM |
What is the end play on the crank??
wrench87 What is the end play on the crank? Rod clearance I like to run about .020-.025" This number is with pistons in the holes, rods set to to torque spec or pull of rod bolts. This is with a crank at .006" end play. Rick L
|
| wrench87 |
08-19-2010 05:30 PM |
i dont know all the particulars but he told me it had .027 side clearance this is with all new parts, my crank journals were offset the crank had to be cut he said it was like they cut the crank then hardened it and the journals were distorted. i am very unhappy with this whole fe experience, you should see all the problems i had with my stage 1 heads, diamond pistons, rpm intake all poor quality. i should of just built a 427 windsor with a dart block.
|
| Excaliber |
08-19-2010 06:09 PM |
When your starting from scratch with a bunch of parts your trying to assemble, new or used, "stuff happens". You could be running into similiar problems with a W block combo just as well.
|
| Barry_R |
08-19-2010 07:11 PM |
Side clearance of .027 is high - but won't really cause any problems. I have every single one of the RPM steel cranks I use cut/fixed - I do not even bother to try them out of the box. Almost sounds like your crank grinder got a little happy with the cheeks.
I use primarily Scat components in all of my kits and assemblies - they seem to be a good deal better in terms of dimensional control compared to the other importers. There is a reason that I use all the particular parts that I do....
|
| olddog |
08-19-2010 08:46 PM |
Doesn't excessive rod clearance result in lower oil pressure or at least more oil slinging off of the crank?
|
| steelcomp |
08-20-2010 01:32 AM |
Quote:
Originally Posted by olddog
(Post 1072724)
Doesn't excessive rod clearance result in lower oil pressure or at least more oil slinging off of the crank?
|
Bearing clearances and oil pressure/volume are what dictate the amount of oil thrown from the crank. Side clearance has nothing to do with it. |
| elmariachi |
08-20-2010 07:01 AM |
Quote:
Originally Posted by steelcomp
(Post 1072760)
Bearing clearances and oil pressure/volume are what dictate the amount of oil thrown from the crank. Side clearance has nothing to do with it.
|
I'd like to hear other opinions on this. |
| DAVID GAGNARD |
08-20-2010 07:46 AM |
Quote:
Originally Posted by elmariachi
(Post 1072801)
I'd like to hear other opinions on this.
|
me too..........
David |
| scottj |
08-20-2010 07:47 AM |
Quote:
Originally Posted by elmariachi
(Post 1072801)
I'd like to hear other opinions on this.
|
Many engines have been built with a 1.771 Honda-size rod that is .675 wide on a 1.900 wide journal. Combined total side clearance is .550". Bearing clearance determined pressure and throw-off. |
| Jerry Clayton |
08-20-2010 08:33 AM |
Bearing clearance determines oil flow UNLESS side clearance is inadequte
Lots of newer very high level engines use huge side clearance however they control rod placement by centering at the wrist pin---similar to a 2 cycle with top guided rods
|
| steelcomp |
08-20-2010 09:44 AM |
Quote:
Originally Posted by Jerry Clayton
(Post 1072829)
Bearing clearance determines oil flow UNLESS side clearance is inadequte
Lots of newer very high level engines use huge side clearance however they control rod placement by centering at the wrist pin---similar to a 2 cycle with top guided rods
|
In agreement with wht you stated, but to elaborate, side clearance would have to be very tight to be inadequate when you figure you have a total area of clearance of just over .004"sq. around a 2.200 journal with .0025 clearance and a .5" wide bearing. No more oil is going to pass through that bearing and come off that crank than that .0043" sq. of area will allow. Using the piston pin boss to locate and guide the rod instead of the crank journals, as mentioned before, allows narrower rods and bearings, less friction, less heat, less recip. mass, etc.;) |
| Jerry Clayton |
08-20-2010 09:52 AM |
and they also now make bearings in the honda diameter and us type width
|
| All times are GMT -7. The time now is 04:04 PM. |
|
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link:
