Yeah, for now. I did just get a second oil cooler in the mail yesterday though along with this gem:



I'm going to see how well this one works by itself before I install the second one. I have an autocross this weekend

 

*sigh*.....

so I blew up my engine again on Sunday morning. I was leaving to go to an autocross when my car decided it was going to boost to like 20 psi (I should be running ~12psi).... and then crack the rear iron.

I'm pretty sure my temporary wastegate actuator fix (wrong sized circlip) failed... and somehow the wastegate arm pinned the wastegate closed when it came off.

new rear iron has been ordered from mazdaspeed... I'm going to try to get this re-re-built and back up and running for and autocross test and tune on the 28th...

 

Sorry to hear it.

I am battling a prespool actuator rod that keeps falling off. A bit of the original c-clip is so rusted in the groove I can't get it out. I can get a new c-clip in, but it doesn't fully seat and pops out.

I am going to tack weld a washer to the c-clip pin.

I don't know if you can still get it (discontinued), but the Greddy pop-off/relief valve saved my FC from overboost many a time.

It threads into a 1" NPT nipple (I used an aluminum conduit nipple). Back the hex shaft out and then in to where you just feel it engage spring tension and then the # turns per boost opening is quite accurate as per the (Japanese) instructions.

Set it two psi above what you want to run and check it isn't opening by putting grease on the piston exposed through the port. You can set it this way too.

 

Oh no! I'm sorry to hear Did you have overboost protection enabled in the megasquirt? you can set it to pull out timing, so anything above 15 psi right now I have it pull out like 5-7 * of timing.

 

I did... I went and looked at it yesterday and for some reason I had it set to 220 kpa (17.4 psi) and set it to drop 14 out of 15 ignition events... I'll be setting it further down (maybe 14 psi) until I can get my car tuned a bit better. I don't think my table even goes up to 220 kpa... which was probably the main reason it went.

I paid for speedy shipping on the iron... it'll be here tomorrow. I also ordered a giant pack of circlips hopefully there is one that's the right size. from some research it appears a 3/16" circlip should be the right size, but we'll see. the stock one is probably metric, which I couldn't find anywhere

made some progress on the engine last night:


I'm going to attempt to not pull the turbo or LIM or oil pan.... and just pull the rear iron and keep the rest of the engine together.

Here is a thread I started asking about it if anyone is interested:
https://www.rx7club.com/general-rota...-iron-1046365/

https://www.rx7club.com/2nd-generati...-*pic-1008221/

 

Engine is out:




and here's the crack....

 

I would check the apex seals for warp from the heat of detonation and cracking just in case you hadn't planned on it.

My last engine had a mystery leak for a couple weekends of racing. I confirmed it was the rear iron at the dowel and when I took the engine apart the rear 3mm factory apex seals were all cracked down the middle. I was just lucky it hadn't come apart.

 

I'll probably check the rear apex seals, but I don't think I've heard of anyone messing up a set of ALS seals.

 

current status of the engine, pretty much ready to start taking apart (just need clamps):


new rear plate came in... new and improved thicker casting version


then I got the drill and tap out and immediately tried to break it:


but it turned out fine, tapped the rear coolant nipple for 1/4" NPT for my turbo coolant line (same as on my old iron):


Now I have to clean up the stock port again like I did on the iron that's on my engine and we should be good to go.

 

I don't even wanna know how much that iron cost new and overnighted......

 

haha, I didn't overnight it, but fast shipping wasn't cheap :P. I ordered it through Mazda Motorsports development (mazdaspeed) so I got a discount on it Helps offset the expedited shipping costs...

 

btw, even overnighted it still would have been cheaper than a new housing... I <3 ALS seals

 

put in a long day yesterday:

Here's the crack, there is another slightly smaller crack that didn't go all the way through


I wasn't really taking pictures, but the engine is back in the car. everything went ok. I re-used my pineapple racing HD water seals and oil o-ring. they looked fine.



I just need to install the starter and the down pipe and I'm good to go. I did break the down pipe to mid-pipe gasket while moving it so I ordered another one, should be here tomorrow.

I might try to replace the cable that goes from my circuit breaker to my starter while I'm at it. I have a feeling it's been causing some of my starting issues as neither of the ends are particularly good.

 

I also rounded off the fill plug in my diff while attempting to change the oil out with some OS Giken 80w250. so I ordered some lug nut extractors to try to get it out...

 

ouch

I hope the engine holds up! what do you plan on doing to remedy the failure from before?

I meant to send a PM to have you send measurements for your vmount. It looks like there is a steel plate sandwiched between two pieces of aluminum that act as ducting?

 

The failure was due to either my wastegate getting jammed closed by the wastegate actuator falling off or the clip I used to secure it getting snagged on my turbo heat blanket. I ordered a bunch of metric external snap rings and used one of those, hopefully it'll work better, it looks far more secure...

I also replaced the rear iron with a '91 TII style iron with a much larger oil passage casting which won't crack as easily.

I'm also updating my firmware of the megasqirt (I'm on a pretty old beta/alpha build) to allow me to use some of the new safety features. and I'm definitely lowering the boost limiter to something around 13 psi.


I need to improve the ducting on my v-mount, but there is basically a metal bracket which acts as the frame that the top of the radiator and the intercooler are bolted to with a large sheet of aluminum bolted to it.

Here is a different picture:

 

i would do that! in fact i'd lower the boost limiter to basically the spot where you're tuned +1psi, and then as you tune it you can slowly raise it. walk before you can run!

 

haha yeah... the plan is to run 12 psi, but I'm a bit worried about boost creep.

I'm also going to be swapping out my Greddy boost controller with a solenoid controlled by the MS3 pretty soon, so that'll give me a lot more control over it... in the end I think this damn wastegate is going to be what forces me to go with an aftermarket turbo.

 

Will this be the first time you'll get to run the V-Mount with the revised oil cooler location? I know you had said you moved it maybe a week or so before the rear iron took a dump, is that right?

Progress was pretty swift lol.

 

besides driving it down the street about a mile and cracking my rear iron, yes. Hopefully I'll get to drive it a bit further this time.

 

Finished up the car and drove it to work today. Everything seems awesome.

wastegate is working well again. I set the boost override to 195 kpa (~14 psi). Took a look at my fuel map... it only goes up to 205 kpa, so the 220 kpa boost limit was really dumb, I'm not really sure what I was thinking when I set that....

The bad:
I forgot to plug in my o2 sensor before I started the car and killed it... picked up a new one from autozone hopefully that fixes it (innovate widebands just use VW jetta o2 sensors).

The car is still having starting issues... anyone else have starting issues with bin mounted batteries? how do you have yours grounded?


The new oil cooler placement cools the oil really well (almost too well haha). it was pretty much hovering around 170-180* the entire time (oil cooler thermostat temp). one time it got up to 200, but that might have been because I was sitting still... I forget before it would hover around 230-240 on the highway....

 

Where do you read your oil temp? i am reading mine from the oil pedestal and mine shows around 170 at all times. I cant believe yours was that high before.

You work quick! If I did that to my car I would not have even had the engine out yet. congrats! Hope you do well in your upcoming autox.

 

from the oil pedestal (i have a re-speed oil pedestal.) yeah... it was pretty bad.

The autocross this weekend is a test and tune/school. I should get a million runs and hopefully learn something.... haha.

This will be the send off for the 4 hoosiers I got for $20 at the beginning of the season I'll run them till they cord, switch to the new much better condition (but still used) hoosiers to see how much time I drop, then 4 runs later I'll probably switch to my NT01s so I don't use up the good hoosiers... Hopefully I can fit 8 wheels and tires on my trailer/in my car

One of the reasons I worked so fast is I missed this test and tune in the spring because my engine blew right before it and didn't want to miss it again... and the last autocross of the season is next weekend (10/6). It did take me like 2 months to rebuild my engine the first time

 

Get a car battery(dry cell), I don't think the little motorcycle battery have the cranking amps needed for the rotary. Check all battery grounds, and solder joints. Keep up the good work.

 

when i did mine i had an teeny little battery in the back. good sized battery cables, ground was right near the battery on the unused seat belt bolt i think.

the little battery didn't cut it, switching to a stock sized battery made it work just as well as stock