Resurfaced Irons
#1
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Resurfaced Irons
Well I just picked up my irons from the machine shop. I had them milled to clean them up a bit. 1 surface needed .005 one .004 and the other two .003. I have read many different opinions on the life expectancy of the motor with resurfaced irons. I think if I can get a solid 50k miles out of this motor I would be happy. Also, is it absolutely necessary to lap the irons? The finish it pretty smooth as it is. Let me know what you think.
#2
It's finally reliable
iTrader: (18)
i read some where that it was not good to resurface irons mirror smooth.
yaw---A housing that is lapped mirror smooth will have little or no oil retention. This is clearly illustrated when applying assembly lube to a mirror finished housing. Rather than spreading evenly across the surface, the lube will bead up much like water on a freshly waxed car.
yaw---A housing that is lapped mirror smooth will have little or no oil retention. This is clearly illustrated when applying assembly lube to a mirror finished housing. Rather than spreading evenly across the surface, the lube will bead up much like water on a freshly waxed car.
#6
TANSTAFL
iTrader: (13)
Sorry, mis-typed.
Oh, that is a good bit of wear... but I'd be afraid that too much hardened surface was removed.
I've read several threads about resurfacing/lapping and I don't recall anyone having a straight answer as to how much was safe to take off. Some said none and some said a small amount... but that was a while ago. Did you try to dig up any of those threads?
I've never had a need to do it since all the irons I've built with have been < 1/2 of the allowed wear.
I've read several threads about resurfacing/lapping and I don't recall anyone having a straight answer as to how much was safe to take off. Some said none and some said a small amount... but that was a while ago. Did you try to dig up any of those threads?
I've never had a need to do it since all the irons I've built with have been < 1/2 of the allowed wear.
Last edited by alexdimen; 12-09-08 at 11:13 AM.
Trending Topics
#9
always modding
Join Date: Mar 2005
Location: on a tiny island in the middle of a sea
Posts: 1,667
Likes: 0
Received 3 Likes
on
3 Posts
if u can't get them re coated with nitrite they are basically junk..
I had the same issue... I had mine re-surfaced..
then I did a search.. only to discover that I basically ruined them..
I ended up buying a good used one instead.. and the old one became a pretty door stopper
I had the same issue... I had mine re-surfaced..
then I did a search.. only to discover that I basically ruined them..
I ended up buying a good used one instead.. and the old one became a pretty door stopper
#10
TANSTAFL
iTrader: (13)
if u can't get them re coated with nitrite they are basically junk..
I had the same issue... I had mine re-surfaced..
then I did a search.. only to discover that I basically ruined them..
I ended up buying a good used one instead.. and the old one became a pretty door stopper
I had the same issue... I had mine re-surfaced..
then I did a search.. only to discover that I basically ruined them..
I ended up buying a good used one instead.. and the old one became a pretty door stopper
On another note, when I glass bead blasted my coolant seal grooves, I got some of the adjacent surface too. I noticed that it gave it a nice matte finish and when I looked at it under a microscope only the finish was slightly changed, it didn't remove any significant amount of metal.
Maybe putting a matte finish on used housings can be a DIY process. It'd be interesting for someone to try it on a larger scale on an engine and see if oil consumption was changed or anything and measure before/after wear.
#11
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Well I already have a few hours of porting as well as 300 for the grinding so I guess i will be sending them out for nitriding. Who is the closest shop to NJ? Or does anyone know where to get the materials to diy?
#12
Racecar - Formula 2000
On another note, when I glass bead blasted my coolant seal grooves, I got some of the adjacent surface too. I noticed that it gave it a nice matte finish and when I looked at it under a microscope only the finish was slightly changed, it didn't remove any significant amount of metal.
Dave
#14
TANSTAFL
iTrader: (13)
I think many people never see that kind of thing because they don't bead blast the grooves.
Most people just scrape it with a wee screwdriver and the crud stays in the low spots. I wanted a bare metal surface to hold the seal and hylomar that couldn't erode or break away from pressure.
Besides, that's not that part that I've seen fail... it's the thin cast lip that's on the lower part of the irons that falls into the channel and lets the ring slip out.
#15
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
I wonder if this would work
http://www.zypcoatings.com/Datasheet...NDBStopOff.htm
NDB Stop-off coating is a "Do All" coating for heat treating, being effective for all nitriding, carburizing, and carbonitriding atmospheres. NDB is a safe, easy-to-use water-based 100% inorganic ceramic formulation that provides a hard, abrasion resistant barrier layer on all metals. NDB is proven effective for fluidized bed processing where abrasion resistance is mandatory, but can also be used in conventional furnaces. Apply like ordinary housepaint by brushing, spraying or dipping. Remove residues after use by using steel brush, bead-grit blasting or other mechanical means. There are no environmemtal and flammability problems like those of solvent-based stop-offs
http://www.zypcoatings.com/Datasheet...NDBStopOff.htm
NDB Stop-off coating is a "Do All" coating for heat treating, being effective for all nitriding, carburizing, and carbonitriding atmospheres. NDB is a safe, easy-to-use water-based 100% inorganic ceramic formulation that provides a hard, abrasion resistant barrier layer on all metals. NDB is proven effective for fluidized bed processing where abrasion resistance is mandatory, but can also be used in conventional furnaces. Apply like ordinary housepaint by brushing, spraying or dipping. Remove residues after use by using steel brush, bead-grit blasting or other mechanical means. There are no environmemtal and flammability problems like those of solvent-based stop-offs
#16
In the burnout box...
iTrader: (32)
I wonder if this would work
http://www.zypcoatings.com/Datasheet...NDBStopOff.htm
NDB Stop-off coating is a "Do All" coating for heat treating, being effective for all nitriding, carburizing, and carbonitriding atmospheres. NDB is a safe, easy-to-use water-based 100% inorganic ceramic formulation that provides a hard, abrasion resistant barrier layer on all metals. NDB is proven effective for fluidized bed processing where abrasion resistance is mandatory, but can also be used in conventional furnaces. Apply like ordinary housepaint by brushing, spraying or dipping. Remove residues after use by using steel brush, bead-grit blasting or other mechanical means. There are no environmemtal and flammability problems like those of solvent-based stop-offs
http://www.zypcoatings.com/Datasheet...NDBStopOff.htm
NDB Stop-off coating is a "Do All" coating for heat treating, being effective for all nitriding, carburizing, and carbonitriding atmospheres. NDB is a safe, easy-to-use water-based 100% inorganic ceramic formulation that provides a hard, abrasion resistant barrier layer on all metals. NDB is proven effective for fluidized bed processing where abrasion resistance is mandatory, but can also be used in conventional furnaces. Apply like ordinary housepaint by brushing, spraying or dipping. Remove residues after use by using steel brush, bead-grit blasting or other mechanical means. There are no environmemtal and flammability problems like those of solvent-based stop-offs
#18
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Well I found a company that can either gas or Ion nitride the plates for $1.50 a LB. not to bad if you ask me. I just need to read up on which process is better. Would it be worth to have the rotors done as well?
#19
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
would a surface hardness of about 400-500 HV with a maximum depth of 100um be good? Should I have anything else treated as well? Eccentric shaft? Rotors? stationary gears?
#20
Senior Member
that search button is a real doosie
https://www.rx7club.com/rotary-car-performance-77/iron-nitriding-473596/
https://www.rx7club.com/rotary-car-performance-77/iron-nitriding-473596/
#21
Senior Member
Thread Starter
iTrader: (38)
Join Date: Jul 2008
Location: Brick, NJ
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
that search button is a real doosie
https://www.rx7club.com/showthread.php?t=473596
https://www.rx7club.com/showthread.php?t=473596
#25
Rotary Enthusiast
iTrader: (3)
Join Date: Nov 2001
Location: michigan
Posts: 1,018
Likes: 0
Received 0 Likes
on
0 Posts
looks good.
Don't forget to re plug all the oil galleys copper factory plugs, because thy will leak from the heat treat. Also the 2 coolant lines on the rear iron will also leak.
If you address those issues you will be good to go....
Don't forget to re plug all the oil galleys copper factory plugs, because thy will leak from the heat treat. Also the 2 coolant lines on the rear iron will also leak.
If you address those issues you will be good to go....