tom jelly

Just finished bolting everthing together and thought I'd share a few thoughts. The engine was making great power and 12+psi, but using coolant at the end, and after 96k plus hard miles and 1 sucessful blockweld job I figured it was time for a new engine.
1. don't bother with blockweld unless you bypass the radiator and heater core during the treatment, and clean out the turbo coolant supply line banjo bolts after treatment (they were 85% blockwelded)
2. Turbo timer value is very debateable. I bought my car with over 85k hot georgia miles on it THEN modified it and ran it at the track and on the street (80% track) to 96K. No turbo timer ever. I don't know if the guy who had the car before me ever let it cool down ever. turbos were clean, other than poor seals allowing oil into the intake. The hot side seal ring on both turbos had worn to a rounded profile on the inside, that is, the shaft side, and there was a corresponding matching deposit on the shaft. YOU MUST REMOVE THIS DEPOSIT WITH A DENTAL PICK TOOL OR SOMETHING WHEN REBUILDING THE TURBOS OR THE NEW SEAL RING WILL NOT SEAT FULLY. I actually thought this was part of the shaft until I saw the new seal ring had a square profile. the shaft mic'd OK. I think this deposit is more due to being worn out than heat soak or anything else. no oil coking in any other areas or lines. BTW both turbine housings were well eroded, one of them looked like someone took a cutting torch to the inside of it, with a 3/4" long slice. plenty of cracks in the gasket surface as well. lucky I had a spare set of low mile turbos and manifolds (which I rebuilt anyway)the turbine wheel from the eroded housing had a perfect profile, but the blade surface was slightly etched, and the etching was still visible after glass beading with a pencil blaster. This unit was rejected. The rebuild kits from turbo city were easy to install, but will require both super size and tiny .040 snap ring pliers, and the tiny ones will likely have to have parts of them ground down a bit to be able to reach the holes. a pencil blaster w/ very fine grit, and parts washer will also be necessary. handy to have a lathe or drill press to polish the shafts as well.
3. The engine wiring harness was (and still is) hard as a rock. I replaced some wiring by taking apart the connectors and resoldering formerly crimped connections, i'd love to have a new wiring harness, but for the high heat stock sequential twins I wouldn't spend any money on a stock replacement unless I could make one myself out of tefzel (sp?) hi temp aircraft wire. of course the connectors would be a problem. I did a silicone hose job of course. ALL hoses were like glass, and even cutting them off with a razor knife was tough, but I only broke one solenoid. One new motor mount in urethane from rotorsports racing, the old was destroyed. BTW the engine came out w/trans attached, but after lifting it a bit, remove the motor mounts and it will come out very easily. The whole engine compartment was a mess and I contemplated a pressure wash, but decided to try castrol super clean- WOW, the stuff works great (I'm 90% sure its the same stuff as the famous s100 motorcycle cleaner,but only $7/gal); I used it to clean even completely gunked up stuff, no need for a powerwasher.
4 I used liberal amounts of antiseize, don't forget this!
5 I bought brass check valves with viton seals, replaced the stock crappy ones.
6 sent the injectors to rc engineering for cleaning. at 28$ ea, they showed a 5%improvement in flow, but just as important as the peace of mind they included new o rings and pintle caps wich would have cost quite a bit.
7 look inside the crank end, there was gritty crap in there just past the pilot bearing. dunno how this escaped mazda, it may have blown in during transport or something as it was loose stuff.
8 I put in a remote reservoir OMP adapter- this pushed out the pump far enough so the front turbo oil drain line connector flange interfered with the OMP electrical connector. I had to grind off the part of the flange that was in the way, and silver soldered the joint. no interference now. I'll be able to run ashless dispersant 2 stroke oil now, and synthetic after break in.
I'll post some more when I get the thing in and running- the new fluidyne rad looks great.

Tom

pomanferrari

iTrader: (1)

Tom, please post pictures of your OMP work around, I'm in the same situation as you are with engine replacement and contemplating running the OMP adapter.

A question for you: I have a stock turbo set with less than 10K that is submerged in ATF fluid for the last 6 years (yeah my way of mothballing the thing). Should I need to rebuild it or just slap it on?

duboisr

Garfinkle has the 0mp adapter and reclocked the end of the pump to get the wires away from the turbo . He had to drill and tap one hole and do something inside the unit to make it work. Great mod for a long lasting motor. worth looking in to .He uses Amsoil 2 cycle oil .

jdhuegel1

Garfinkle needs a website!

tom jelly

Engine is back in, I didn't take pics, sorry. I took apart a MOP to look at clocking it, looked like it would be more of a hassle to do that so I just cut off the intefering bolt on the oil line joint cleaned everything up with a grinder and silver soldered it. Got this great silver solder and a rosebud tip for my little smith cavalier oxy/acet setup and it worked great. I'm gonna go around silver soldering everything now! Don't go crazy with the heat, and make sure you bolt the lines together in the right position and screw them to a wood jig to keep everything in place while brazing- it looks like the same solder is used on the factory joints, so when they soften up you don't want THEM moving.

tom jelly

Its really no trouble to do the rebuild, but will cost you $300- money you probably don't have to spend if you KNOW the turbos only have 10k miles. I'd look at the blades and measure the play and put them on, then rebuild your current ones and then measure the difference and then you'll know for sure! If you take them apart get an electric engraver and mark everything so you can clock them correctly when you reassemble them. I'm going to rebuild my old setup after I get a little better at welding, as the housings are bad- heat cracked, etc, so I'd weld up the cracks and mill the weld beads but if I have to take things apart again it will be to install a small single for the track applications that I do. I would need a really low lag setup, and it would have to make a solid 400-450 hp to be worth the effort and $$

Tom

Mahjik

iTrader: (1)

Good info for those who have already used the block weld.

spurvo

For that matter, have you looked at the coolant passages of the turbos themselves after blockweld? If the banjo joints are blocked up, I shudder to think...

mazda/feed

so dont tell me that the bleck weleded wont hold since you have done this

jetmech77

So how do you bypass the raditor?