I had a difficult time finding someone in Maryland to grind or "lap" the faces of my engine irons down. I was reccomended to a place by a well known rotary shop in Va. I was quoted $75 per face. I'm not sure if that is a deal or if I am getting hosed. I think that is kind of pricey. It's $300 for all four faces. Am I being cheap?

Has anyone ever had thiers done and if so what did you pay?

 

My builder has Racing Beat lap the irons. Give them a ring (even though shipping would be bad for you).

 

I used Mazdatrix and it was about $70 per side. Mazdatrix and Racing Beat may share the same machining (as I've heard they share some other tasks).

 

Sounds as though $75 is close to going rate. I would not have shipped them either way but thanks rynberg.

 

I payed 50 bones a plate back in 2002 in fort worth texas.

 

Silly question but is this something that can be done on a rotary table grinder like a flywheel machine? Dave, can you ask the machinist what kind of equipment he's going to use when you trach one down? I'm really curious.

Thanks..

Oh, and I heard you met my brother up at Peek Performance. What'cha building? Rotary sand rail maybe?

Dave

 

Yes I met Mark up at peek, nice guy. I have a glass manx type buggy I am building when I get moments away from my rx7.

From what I understand they do the work on exactly that, a flywheel grinder. I'm going to swing in this place in Clinton,Md.to see if I can get a better quote.

 

Cool.. If you have any VW type questions or need parts let me know.. what I can't remember I can pass on to him.

Mark mentioned that you might call Burtonsville Machine. They have done balance work for him before and probably are equipped for that. (301) 490-3131. Kind of far for you though.

 

You do realize when you lap the housings you are removing the nitriting...

 

No I did not. However my mechanic Ray told me he thought the side seal grooves were bad enough that I should get the plates ground down. I am sure if removing the nitride coat were going to cause problems he would not have suggested that I do it. Considering he knows I would give him **** all over the internet for it. He has always been very forthcoming and honest in regards to what is best for my car. PFS has been very good to me over the years and I trust his judgement and to add. I was actually reccommended to the place by Brett at Rotary Performance. He said that he had irons ground down regularly. So if it's not a good idea (assuming that is what you were getting at) then why are two well known shops suggesting that I get it done?

With all that being said I am all ears as to what ill effects would one expect from removing this nitride coating?
Personally I was not even aware that the iron faces were coated with anything. They don't look to be coated with anything.

That all aside, the grooves from the side seals are not going to work. So it's either grind them down or get new irons. If ground ones will last me a couple of years, and I assume they would. Then I am fine with it. Besides I don't want to lose the sweet port job I did on these.

 

Both Racing Beat & Mazdatrix are excellant guys to work with, and well worth the shipping.
my 2 cents

 

Dave,

they'll last you a few more years. I ran lapped irons for 30k miles or so with no problems.

Rich

 

I usually charge $30 per side to surface grind them.

Couple of things to ask/tell whoever does them for you though especially if they haven't done these before:

What type stone are they using...Some types of carbide stones can actually embed into the iron housings which will then only wear out the sliding seals prematurely. Usually the first ones to go are the oil control rings which you will notice by the motor starting to burn a little oil. Aluminum oxides work great for surfacing the plates.

If you are using the teflon o-rings then tell them not to take more than .006 off or if using the stock o-rings you can take off as much as .010 before you will lose the depth of your o-ring groove. Normally you only need to take off about .003 or maybe .004 to clean up the plates. Taking off to much material and you run the risk of blowing out a coolant seal wall when you try and compress the o-ring.

 

From my dark and damp archive -
I'm not sure if this place is still around but at least they are on the "right" coast.

Lapping & Re-nitriding source.
LAPCO Industries, Inc.
5440 HWY. 55 East
Lake Wiley, South Carolina
(Att. Bob or Dick Pasture)

Found a new number on the web - so I guess they are still in business -

803-831-0324, 888-887-2109 (toll free)

 

You certainly won't get longevity out of the irons if they are not nitrided, which is why remans have their irons sent back to Japan to the original manufacturer for lapping and nitriding. This was a deciding factor for me in getting a reman a few years ago for my FC after the Brett Depedro rebuild failed after 58K. I wouldn't trust him to work on a child's wagon. My irons were way out of spec (as many other things were after that hack worked on it) and at that time there wasn't anywhere to get them nitrided. There is at least one place now according to Dave Barninger. Ask yourself how long you want your motor to last. As Rich said he has 30K on his. I expect 100K out of a rebuild and would not lap without nitriding.

 

Thanks for the input guys. I'll make a few phone calls and think out my options.

 

Niether of those numbers are good. The 888 is to a different co. and the other is out of service. Thanks for trying.

 

58k out of a rebuild is pretty decent from what I see, with many remans and rebuilds coming in my door with <30k on them. Hell, most FD's did not make it to 58k when they were new and stock, hand assembled from japan out of all new, shiny, in spec parts. I guess you wouldnt trust those guys to work on a paper airplane, either, huh.

 

FWIW I have yet to see a lapped set of irons last more than 10k without causing problems. I dont know if they weren't done right, or if the idea is just not sound. Most of them end up wearing down MUCH faster and causing severe smoking and compression loss problems, whereas just reusing a lightly worn set of original irons would not have caused a problem...even 4 or 5 thousandths of wear on an iron will not significantly affect compression or cause excess wear in most cases, in my experience. Personally my opinion is it's one of those things better left alone, you can easily do more harm than good. IF you have a problem with an iron that is too bad to run, IMO you hunt down another used one for 100 bucks and go on with life.

 

Kevin,
My problem is with one person, mentioned above. There were many internal engine issues that I found upon disassembly as well as installation issues. It is disappointing when one's personal situation dictates having someone else do engine work for you and you receive it back with zero oil pressure at idle warm. You take it back and it is returned to you in the same condition ! Long story short, he is incompetent, as proven last year when one of his former defenders suffered two engine failures, costing him most of his auto-cross season waiting each time for repair.

Surely you aren't serious that 58K is a reasonable life span for these engines. I got 127K out of my TII motor (not knowing all that I do now, thanks in part to this forum) and am at 96K on the FD (with blown o-ring but good compression). I bought both new. The infamous John Duff had 140K plus on his FD original motor before his son balled it up. The premature failure of most FDs can be attributed to poor service, owners who ran the **** out of them, and excessive heat largely caused by the pre-cat. My only problem was the common one of failure of the 1st design intake manifold gasket. I've been working on motors as a hobby for forty-five years now and have high standards that produce better results than what you have seen from others work. I agree with you that good used irons are probably the way to go for many situations, although I wouldn't want more than .003 wear.

 

All I could say is that I want to see some pics of lap irons.
Some I've seen on this forum, I think its better not to even send them out.

I had my engine lapped (still sitting on the ground), but what I know of lapping is that it needs to be done correctly. My builder in Alabama built his own lapper and it takes him 1-2 hours to lap one side. But when its done, its flat, smooth, and no sign of any swirl marks.

Also, every engine my builder built have been lapped. Far as I know, he has a great track record (building rotary engines for 25 years).

Fd3Boost, if you are interested, I'll ask him if he will lap it for you (I think he charges $60/side).. He only builds 1 engine or so per month and he also don't like to get phone calls.

 

Actually I have Ray at PFS looking to see if he has a decent set of irons around his shop I can buy off him. By the time I spend the money on getting my old ones lapped and renitride coated. I could likely afford better irons. Besides it will give me a chance to port another engine.