Nah, the engine was on its last leg anyway, that leg just happen to break yesterday. I found what looked to be exhaust carbon on my overflow dipstick, the temps were rising much higher than they normally had, and coolant was gushing out the overflow tank. I did a coolant system pressure test and the pressure kept building up to 25 psi untill I shut off the car.

 

I'm not an engine builder, and the motor I put together and in my car has 8,600 miles and sees 17psi boost every time I turn her on...of course I gradually up'd the boost has I began to be more confident. I turned WI on once I went over 14psi on pump gas. I used "used" motor parts and feel that the car does have lower compression than optimal (spool is a little slow...but once she hits, HOLD ON!), but I didn't know if the motor was going to crank at all, haha!! I feel that I've learned a lot and the next motor I build will be much much better...not that I'm looking forward to that.

I also get around 22mph on the interstate

 

Wow, that's pretty slow... I thought the minimum speed limit on any US interstate was 40 mph

 

lol

 

opps...

 

Hi guys, this is my first post here.

I rebuilt my own motor after 55k (coolant seal failure) and it lasted only 4500 miles.

Word of advice, DO NOT get your end or intermediate housings lapped flat without getting them re-nitride hardened.

I work for an engineering company and have access to lapping facilities etc. My housings were warped no more than 0.003" at the worst point and I decided to lap them perfectly flat (ensuring coolant seal / combustion seal groove depths were not compromised).

At the time, I didn't realise there was a thin layer of hardening on the surfaces and proceeded to lap between 0.001" and 0.003" off all 4 surfaces for them to clean up (the surfaces themselves were in very good condition prior to lapping).

Car runs great for 4500 miles, then starts to blow faint amounts of blue smoke out the exhaust (under throttle and at idle).

After much heartache (not to mention wallet ache) I decide to pull the motor again as the symptoms did not seem to point towards turbo problems.

I couldn't believe the wear on the surface of the housings after only 4500 miles. Both sides of the intermediate housing have 'v' shaped grooves 0.015" to 0.020" deep along the oil control ring wear line.

The end housings in the region of a 0.006" to 0.008" step along the apex seal wear line.

Check out the FAQ's on Atkins Rotary's website, they explain why they do not offer lapping as a service to customers.

Unfortunately for me, I found out too late, don't you do the same.

Gary

 

Rick Engman lapped my irons...but he has been building for quite some time, so he has it down to an exact science..."this much weight, for this much time" then "center the weight here for this much time", etc...I can't remember what all he said, but I don't believe he re-nitride hardened them, as he had me sand/polish them up before I put the engine together.

your post is interesting...

 

I've got a Pettit rebuilt with over 51,000 on it with alot of harddriving miles. Used new rotor housings, that was 5 years ago. Makes around 300 rwhp, sequential set-up.

Tom