I had a conversation today with a reputable shop that rebuilds engines... I won't list their name because they are great people and know their ****. I just need to get a second opinion about it.

Basically the conversation was about Atkins Rotary rebuild quality... My last 91NA got a rebuild and I loved it. However, I only got about 25,000 miles on it, it was great and pulled hard. The individual I spoke with basically said that they see a LOT of engines blown after only 10-30k miles from Atkins... His argument was that their viton oil rings weren't designed for the kind of movement that rotors make and end up leaking WAY before the OEM counterpart. Also, the atkins seals, made of a softer steel, are more porous.. lots of gaps in the steel under a microscope... they don't make as efficient of a seal. He also stressed the fact that they shouldn't be using used rotor housings and that you can't get a decent rebuild to last any longer than 30-45k miles on a used rotor housing. The ONLY way to get another 100k miles out of an engine is to replace the rotor housings, bearings, and use an OEM rebuild kit.

I'm trying to get the most out of my money when I get an engine... I had assumed that my 2500 dollar budget was going to be sufficient, but its starting to look more like 3000-3500. Looks like I'll have to sell a kidney.

Any thoughts?

 

ive heard claims from people saying theve gotten 50-90k on there rebuilds reusing housings and such.

 

Yeh man I'm in the same issue...trying to get the most bang for my buck, but luckily in my location there are some good shops around me. Try and contact a local shop and see if they will spec your engine out for you if you bring it to them. From all the things I have heard from numerous people it seems like every engine is different as far as what your rebuild will be like. All I can really think of doing is just biting the bullet and forking out for a flawless rebuild with OEM stuff

 

Well. I don't have the engine ready to go to a shop yet... Its still in my car.. and I use it. I do have another core that I was thinking of using to get rebuilt. But I am scared to think of whats inside it. But I guess I could tear it open and find out. then perhaps take that one down..

Biting the bullet for me is much more difficult as I'm unemployed.. Unemployment insurance doesn't really cover engine costs. So, while I look for a job to support my addiction, I'll have to sell **** to get the money. I feel like a meth-head.

 

Look at it from a return on your dollar point of view.

You own what averages out to be about a $3000 car. The average person drives 12,000 miles per year. So a rebuild that will get you about 30k-50k miles before funking out on you is still 3-5 years worth of use. Are you willing to spend more than your car is worth to get an extra few years that you likely will not use? Its very likely that you wont keep that car or engine for 100k miles, so why pay for it.


Unless this car will never be sold again, or you are going to make a badass engine that you are going to sink some serious money into, why bother with the added expense of a essentially new engine? You spend $1300 on a 30k-50k rebuild, or $4000 on a 100k mile rebuild. The money says that you should roll the dice and rebuild twice for 2/3 of the cost....


BC

 

I will be getting some porting done, but.. nothing crazy.. and you ARE right... by the time 30-50k miles rolls by, I'll probably end up being ready to throw something more radical in anyways.

But, I'd like to know where you are getting rebuilt engines for 1300 dollars.

 

Kevin Landers at Rotary Resurrection did mine for ~1300. That included emissions removal and an auxiliary port job.

 

That's BS about requiring new rotor housings.
Have you ever priced a new pair out???
I've got about 30k on my rebuilt 13BT, and it's still running fine.
It originally had about 90k miles on it initially.

I think it's more the condition of the used rotor housings that will dictate how much longer it will last.


-Ted

 

I hope the "secret shop" you are referring to is not Pineapple Racing, because they themselves have been known to be shady builders as well.

 

That made more sense... an over generalization like "all rotor housings need to be replaced" is a bad one to make.

Whats everybodies opinion on bearing replacement? Lots of shops don't replace those.. and in MY opinion, they should always be replaced.... well, unless there's like 30k on them or something. but, for my 147k engine... fo sho!

 

^ Braille **** avatar!!!!! Too funny.

 

Rotary Resurrection is one place.


Another is your garage. get a rebuild kit and the video and do it yourself. For what you pay you will get a lot in return, plus the knowledge that you KNOW what was put in.


BC

 

I'd go with Racing Beat's recommendations, since they have been doing this for a LONG time...

Replace bearings only if significant copper is showing.


-Ted

 

Glad you like.

 

Well, my options are definately better now, knowing a little more about the rebuild process... I know a lot about how the engine works and what the components are; I just hadn't taken the time in 6 years to learn about rebuilding theory. Anybody know any good books/articles? Or will the video teach me everything I need to know (LOL).

 

There is a reason most of the rebuilds that are done cheaply and use 3rd party seals do not last. It is very uncommon to see one last as long as a new OEM engine. Even good piston builders will say you can just reuse stuff it must be in spec and you must use the right parts.

It is very simple to see if you want a motor to last at least as long as the original did then build it to that standard.

Now if you’re going to do this why make shortcuts? I replace rotor housings and all new OEM seals on every rebuild. But I spec the bearings out because they never touch anything therefore they are usually very much in spec, same with the rotors and Eshaft.

If you complain about the price of new housings then look at it this way. If they are within most people’s tolerance of a used housing then resell them both for the price you paid for 1 new one and save some money.

Now if you built the motor 5k miles ago and oil seal goes it is probably safe to say the housings are reusable.

 

i use atkins seals and OEM gasket kit, in close to 2 years i haven't had a single engine failure and i haven't had any customers pony up for new rotor housings yet. my personal engine has close to 30k on it and the rotor housings originally had about 90k on them- fully modded and daily driven.

replacing the rotor housings and using OEM seals almost doubles the cost of the rebuild, something alot of people just CAN'T afford. working on that budget is not something that is all that bad, do you really think even a rebuilt engine with used rotor housings is not capable of making it to another 80k miles or more? that depends on the condition of the rotor housings, irons, tuning and cooling system integrity.

what is the main reason for failure of rebuilt engines? if you say apex seal failures then you are referring to faulty TUNING. if you say coolant seal failure you are referring to cracked irons which is a result of lack of maintenance or just plain old tired irons that cracked because it was their time, remember these engines have been heat cycled tens of thousands of times, replacing all of the irons with new ones adds $1500 to the price of a rebuild.

i think some people need to start getting their facts straight before telling people why these engines fail!

FCs have less issues with rotor housing electrolysis and more problems with thin iron castings failing. FDs have more rotor housing electrolysis issues and less problems with iron wall failures because the irons have had less heat cycles, the iron castings are basically identical to FC irons but they show less abuse because they generally have less miles and age.

 

From what I understand, the main wear point is the apex seals.

 

the main wear point is the apex seals, which is why i always replace them regardless of their condition when doing a rebuild. but how often do apex seals really wear beyond spec? i personally haven't seen any out of spec after removal, apex seals fail due to boost, carbon build up, detonation, heat warping and a few other reasons not generally due to normal wear and tear which is why n/a's rarely have apex seal failures.

 

Main wear point I notice is the housings then apex seals and thrust bearings. I personally builder preference rather not take the liability or risk and replace them regardless. As I said there is that 5k motor where the internals are perfect still those get reused. After all you’re in there why cut corners? I mean most of the information on the net is who said she said follow the crowd.

The irons cracking people have there own opinions and recordings you ask me it’s purely detonation! Maybe one lingering case of harmonic rod vibrations cracking them. I think this failure is more prone to center iron. Of course I use methods to reduce this risk.

 

none of the cracked irons had seen detonation, most i have seen were in n/a engines. i am referring to cracked coolant walls not cracked dowel pin lands.

yes both the apex seals and rotor housings take the most abuse but i still will reuse housings regardless of what other people's opinions are and not everyone has an extra $1100 burning a hole in their pocket to toss in new rotor housings. there is no proven methods of reducing the risk aside from recasting the irons. i have tried the JB weld method recommended in the Atkins video but after tearing down my own engine i saw that the coolant and thermal expansion did a number on the JB weld trick so i don't even bother with that anymore.

McMaster Carr coolant seals will help avoid issues with the coolant seal wall failures, even if the coolant seal wall does break off the encapsulated Carr(also known as Rotary Aviation) coolant seals are rigid enough to still hold in place and reduce the internal coolant leakage.

 

If the coolant wall is broken I trash them. I can repair them properly but my time cost more then a good used one. I was referring to the dowel on my previous post.

 

i don't reuse broken coolant wall irons either, there is no proven method for repairing them that i have found.

i however do save them for an experiment i am going to try on my Datsun full bridge project that is going to use all damaged irons and Mc Master Carr coolant seals and a patch on the irons to see if there is a possible viable repair for them.

 

I have a working method but it costs $250 minimum.

 

not worth it since new irons cost a little more and the used irons still are aged and more susceptible to cracking.