Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: paul3944 on July 11, 2006, 10:08:17 PM

Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 11, 2006, 10:08:17 PM
Hi,

Been cleaning all my engine internals and measuring all parts they are within tolerances but i have a doubt about the Rear Housing. :confused:

It has a slight groove about 1.5cm in length and catches your fingernail.
Could i get away with it as it\'s right on the edge(Pic).

Otherwise the housing is top notch shame to skip it :mad:

Many thanks
Paul
Title: Need Advice from Rebuild Masters !!
Post by: mullins on July 12, 2006, 10:10:02 AM
That looks more like an end plate than a housing :Tongue1
Title: Need Advice from Rebuild Masters !!
Post by: ro284 on July 12, 2006, 10:21:12 AM
Too close to the seal groove for my liking Paul!
Bob
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 04:37:31 PM
Quote from: mullinsThat looks more like an end plate than a housing :Tongue1

In the Factory Service Manual and Parts Catalogue there called housings

Front Housing
Rotor Housing
Intermediate Housing
Rotor Housing
Rear Housing

:yes

Paul
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 04:42:01 PM
Thanks Bob for the reply

I think the groove was made by the Apex seal assist piece plus the rear rotor was blown aswell.

Could i get it lapped or would it be more cost effective to replace :confused:

Many thanks
Paul
Title: Need Advice from Rebuild Masters !!
Post by: interloper393 on July 12, 2006, 04:45:33 PM
think your best to replace bud, think its more if you can catch your finger nail on it then a seal and catch and get ripped out.. all new engine rebuilt again..
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 12, 2006, 07:47:52 PM
paul have u checked the drop with a dti (dial test indicator)?
no more than .004" is the tolerance for deviation in flatness, it looks like its the corner seal path where the lip is on your pic, are u sure the lip is not the carbon build up on the outside of the cxorner seal path?
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 08:25:43 PM
Yes Mate,

I used a dial indicator to measure them, I\'ve placed a Rotor on the housing to see if the groove will come into contact with the corner seal path.

And as mentioned earlier if the groove is deep enough it can dislodge a seal

Putting the Rotor on the housing has now confirmed it\'s too risky to use :(

Paul
Title: Need Advice from Rebuild Masters !!
Post by: mullins on July 12, 2006, 09:17:43 PM
Why not get the surface re-faced?
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 09:28:00 PM
Who would you recomend to get it resurfaced by ?
Would it be cheaper to get a good second hand one :xconfused

Thanks for the input everyone  

Paul
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 12, 2006, 09:59:32 PM
u can get the plates re lapped flat but it depends how worn they are to start with, I think the nitride coating on a cast iron plate is .020" thick, so if this is already worn say .006" and then u have it lapped flat taking another 0.010" of, your only left with .004" of nitride on your iron plate.
Ive been playing around with an old inter plate seeing how thick the coating is,     cutting on  a milling machine  at .014" deep from a touch on the nitride i was down to cast iron! so the nitride coating is not deep.
there are heat treatment firms who specialise in hardening, anealing, nitriding, stelite etc all over the place if u look round,
its worth enquiring cause it might work out cheaper to have all your plates recoated and lapped for maximum compresion on all 4 side faces on your engine.
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 10:07:33 PM
Thanks Stuart

Excellent Info :Thumbs-up
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 12, 2006, 10:17:23 PM
I used to skim a lot of aluminum cylinder heads flat that had warped and blown head gaskets and you will be surprised how much material you have to take of some of then to get them flat again! sometimes as much as ..015"

this priciple is the same for the side housings but your limited to the thickness of the nitride once u start lapping flat and whats to say the plates havent been lapped before.
Make a few phone calls tommorow to a nitride coating firm and i think you will be surprised at the price:Thumbs-up
Title: Need Advice from Rebuild Masters !!
Post by: ro284 on July 12, 2006, 10:44:50 PM
I think a lot depends on the way the engine failed if it did! when mine went it was a corroded seal groove, (not enough corrosion inhibitor over the years!) but the result was that my end and inter housings had distorted with the heat it reached,not flat! a new rotor housing would rock\' on them, so had all new housings while i was at it,
Good luck Bob
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 12, 2006, 11:02:44 PM
Think I\'ll check these guys out

Nitriding

http://www.nitriding.co.uk/portal.asp

Paul
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 13, 2006, 09:38:01 PM
good find paul, did u enquire about them resurfacing your plates??
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 13, 2006, 11:15:41 PM
I thought it would be best to e-mail them, so i have enclosed pictures of the parts that require nitriding.

Just waiting for a response, will post here there answer. :wiggle

Paul
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 13, 2006, 11:22:20 PM
make sure u do mate cause i might get my fd plates done and use new rotor housings on my rebuild for some good compresion:yes
did u ask them if they need the origanal nitride taking of down to cast iron, or can they resurface over the old nitride face?
Title: Need Advice from Rebuild Masters !!
Post by: stuart wizy on July 13, 2006, 11:28:19 PM
thinking about it, if you resurface over original nitride this would make your water seal groove deeper and could stop water seal,  sealing correctly.
the tuners have them resurfaced but I bet they wont tell u where!!
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 14, 2006, 07:45:35 AM
So,

It would be best to have them lapped so as to remove the nitriding then have them resurfaced, thats got to be the only way :mmmm

Paul
Title: Need Advice from Rebuild Masters !!
Post by: interloper393 on July 14, 2006, 10:37:42 AM
would this work out cheaper than buying new plates?
Title: Need Advice from Rebuild Masters !!
Post by: paul3944 on July 16, 2006, 10:53:06 AM
They have\'nt replied to my E-mail looks like I\'ve been blown out :Nono!

Either that or they dont cater for the Individual only Large setups :confused:

Paul