JT's M20 Build Thread

[digger]

i'd go with same size if the delay valve is deleted that way on limit the fronts should still lock first (accounting for weight transfer) assuming the front pads a slighty higher friction compound.

[whodwho]

...
- 0.75/0.700 has the best bias % when weight transfer is considered assuming the pad compund front and rear are the same (probably arent)

Good to hear, I have the original .70 I used for the front that I have wanted to try for the rear in place of the current .625 once it is back on the street

I need to make up my mind on whether to go with 0.7/0.625 F/R masters or 0.625 for both, with the stock brakes. I am leaning to 0.625 for both and making a significant adjustment with balance bar. This is just for street use while I get everything working with the motor build.

Do you think I will be irrecoverably ruining the brake balance if I run twin 0.625s and bias a fair bit using the balance bar? Even if it isn't great balance wise fronts should still lock first, and I can likely use a 6.1 pedal ratio as well so hopefully travel isn't abysmal. Really at this point I just need something drivable until I can figure out suspension, wheels and brakes.

In other news, hopefully getting the car back on the lift this weekend, things should then be moving pretty quick.

I started with the .70/.625 with stock brakes and I think you will be better off with the .625 x 2 and like you said between the bar and the ratio adjustments you should be able to get it dialed in

[JehTehsus]

Sounds great guys, thanks for the input. I am going to get that on order with a few other bits here, things are starting to come together and it feels good.

Had some 'fun' messing around with fuel rail a bit more. I ended up getting some socket head bolts so I could lower rail a bit (it was sticking out just a bit too far, I thought). Turns out it isn't enough, you can see in some of the attached pictures that when I got the boroscope in behind the injectors they are clearly not seated. In my best estimation the angle of the injectors is correct, or at least very close, but any simple bracket I build for the nuke rail is going to either push the rail too close to the head and totally ruin the angle, or else like what I currently have, will not let the injectors sit deep enough. For that reason I am leaning towards some spacers, I think another 10mm or so will be perfect.


(yes, I know there is some crap there... paint/powdercoat that was around the rim of that injector hole I believe. I cleaned the friggen IM 30 times before I put it in but there is always something...)






I also discovered my right-angle-swivel-female 8-AN + union fitting is too large/long. Wooohoooo. Going to use one of the right angle swivel fittings like I used on the front of the rail going to the FPR, it is just a bit shorter but that should be all I need, hopefully enough clearance that a tiny bit of engine movement doesn't bump the rail and start a big ol M20 bonfire.... If not, I will have to further modify that blower fan shroud plate.

[JehTehsus]

Car is back in the shop! Will be wrapping up all the last little bits these next couple weeks (although I am still waiting on a few adapters and things that are likely a month out, but nothing major. Just more delays before first run).


Installed the massive brake kit. Currently the 0.75 I had will be running the rears, and the 0.625 for the fronts. This is strictly temporary, moving around the property setup while I wait to get my hands on another 0.625. Kit went together very smoothly, biggest issue I had is my poor cutting skills for the master rods, but really no problems at all.



Installation also went well. Going to mount the reservoir today then see how far I get mounting other goodies and preparing to run fuel lines.

I may have a bit of a bend in the hose for the brake lines (not too tight, but a bit) if I mount it like this. Debating flipping the bracket upside down so the MCs are lower.

[JehTehsus]

Hoses are in (strictly speaking need to replace clutch master and plumb line to it, but brake hoses are in). Overall I am fairly happy with it, will probably try pushing the hoses onto the master cylinder connections a little bit more (they are a nightmare... 30 minutes to get them that far with a heat gun) but they are definitely solidly connected, no air will be coming in there.

Due to height limits the reservoir is right up against where the hood is when closed. I don't think I am going to flip the MC bracket after all, there is no way for any of those hoses to end up caught in the balance bar assembly, which is what I was concerned about.

[JehTehsus]

Final bit of work on the throttle body tonight, aside from some painting touch ups. Not incredibly happy with it, clearances are tight and I had to grind down a fitting. Biggest concern is vacuum and boost leaks... O ring is probably not perfectly seated (I don't exactly have a setup to machine a solid receptacle for it) but I did dump a bunch of thread sealer in there too, so fingers crossed.

[JehTehsus]

Got a little bit done last night, basically just pulled the degree wheel installed the shifter linkage. Somehow mixed up the bushings, so I had to pull it back out and redo it... popping the clip took about 40x longer than everything else combined. Such is life. Also, added a couple furry family members, feel like this place is starting to turn into a bloody farm house, between the chickens, dog and now two kittens.

First time trying out the IE DSSR. Maybe not the most beautiful but seems solid enough. The short shifter is the UUC kit. A discerning eye may also not that the tranny is a little low, this was taken before I tightened up the mounting bracket. You can also just see where the mount is, the one I got welded. Broke again, naturally. I may grab a pic of the poly mounts later tonight and put it up, I followed the IE lower torque spec for them but tbh they look pretty sketchy, I am not so sure it is a good idea. Motor mounts seem totally fine, however.





Coffee for scale. Second night they learned how to climb the tower; buggers are like velcro. Only time they fall off is when they battle for the upper platform, so I have strategically placed pillows around the base until they are a bit bigger.

[JehTehsus]

Nothing too revolutionary yesterday evening, except getting my driveshaft in. I have also included a few pictures of the tranny mounts. Note that they are torqued to the lower spec that IE lists for them - the one with the broken tab and bracket broke when it was torqued, and I noticed it had broken again when I went to loosen it to fix power steering rack. I am not sure if switching back to regular mounts will make a difference or not, however.

[vWBIRDWv]

subbed

[JehTehsus]

Managed to get a bit done this weekend - mostly tedious bits. Fuel filter is mounted, flex fuel sensor is mounted, vac station and power steering reservoir are also mounted. About halfway through getting custom fan brackets together. Ran the brake lines, wish I had one with double ended L fitting; I will probably just get a couple of the short problem ones remade by a local shop.

Also replaced clutch master and slave cylinder, most of the plumbing is done and in place. In terms of mounting, the only thing outstanding at this point is the two catch cans and the remaining fan brackets, then I am running fuel and vac lines.

Here is where the bay is at: still a big mess but getting closer, bit by bit.

[JehTehsus]

Catch cans are mounted. Only thing left at this point is the fan brackets and fan mounting, then a little bit of painting and touch ups and I can get the radiator, power steering cooler and oil cooler all mounted. After that I just need to go through the joys of running hose!

Drivers side CC: Will be connected to the valve cover breather.



View from the bottom:



Passenger side CC: For coolant

[digger]

did you just holesaw to fit that on the driver side (passenger side has the hole for the A/C iirc) ? you dont have ABS? i was thinking of running an air feed/duct up through there was wondering how easy access was with a large holesaw

i ran my catch can near your coolant one but vented down under near the front spoiler

[JehTehsus]

did you just holesaw to fit that on the driver side (passenger side has the hole for the A/C iirc) ? you dont have ABS? i was thinking of running an air feed/duct up through there was wondering how easy access was with a large holesaw

i ran my catch can near your coolant one but vented down under near the front spoiler

Yup, 3.5" holesaw, worked like a charm. I came in from the bottom after drilling a pilot hole and measuring from the top. Only potential clearance issue is the (horn?), you can see the bolt that holds it on the side. So currently my horn is rotated a bit, not sure I really care. If it was a concern I could certainly move it further forward. If you pulled the horn you could very easily get something larger in there, I would imagine 4.5-5 inches without issue and probably bigger.

I am not running ABS - at least not right now, at some point I will definitely work in a modern system. In the meantime I can easily re-purpose the wheel sensors for the MS3 traction control. Old system wasn't working anyway, and then on top of it my friendly uncle helped by completely stripping the threads into it for one of the brake lines, so I just said fuck it and pulled it out.

The coolant one was a bit of a shitshow, I could not use the holesaw because of the existing hole for the AC condenser valve or whatever it was. If I had a piece of sheet metal handy that was the right shape I probably could have mounted it over top and drilled the pilot hole then used it as a guide, but I didn't, so angle grinder it was.

[JehTehsus]

Relatively minor update today, progress on weeknights can be a challenge. That said, I did get a bit of paint on some bits:



Also roughed in two fan mounting brackets. I think once I have everything up and running I am going to do a CAD pass and get brackets properly cut and bent at the local waterjet, but for now it will do.



Some bits also arrived, new fuel line fitting looks good. Also have the other 0.625" MC, so I will swap that into the brake bracket this weekend.

[JehTehsus]

Bit of a late update, actually did all of the below on the weekend.

Nothing too exciting, but I did get the other MC in place. Oddly enough it took a bit of messing around, could not seem to get it so sit flush/parallel to the other MC when the pedal was pushed in without basically advancing the nut all the way to the end, whereas on the other same size MC it is ~4 threads away. Here is a photo that poorly illustrates that:



Maybe BB is a bit misaligned somehow after removing the other MC? That said I was careful when taking it out... anyway, filled it up with fluid/bled the brakes and everything seems ok. Will be rolling it down the hill later this afternoon (uncle and I are playing musical motors with his trucks this weekend, I think 3 trucks and 4 motors, some sort of swap bonanza going on. My poor e30 is once again getting booted from the bay), so hopefully they work because the next stop is the highway our driveway goes directly onto.

I also painted lots of little brackets, such as for PS reservoir. Decided to just order some SPAL ones for the fan, I actually found them after cutting those hideous things on the last post... somehow I missed them first go around ($5 each too, uhg I wish I had noticed them earlier). Oil cooler and PS cooler is mounted, lines are roughed in for PS at the moment.



My 12mm injector extensions also arrived... I had a lot of fun figuring out I actually would need ~4-6mm extensions, 12 are too large. I think I am going to have to go with plan B and fabricate some sort of bracket that will wrap around bottom of manifold mounting points and fuel rail. Here is a nice picture illustrating clearly how the nuke rail does NOT fit with 12mm extensions:



Overall, in terms of what is left before first startup...

• Fix fuel rail for real (I may just tie it down for now, figure out exact bracket mechanicals later when I do a waterjet pass for all the other little bits).
• Build out my AN fuel and vacuum lines (vacuum station adapters should be here any day now). I may also shorten one power steering line.
• Mount the fan and radiator, and run the cooling hoses.
• Become a better person by suffering through the construction of my own wiring harness. I need to place a digikey order for some connectors, otherwise I should have everything I need.
• Torque main crank bolt, lots of other pre-startup checks and little tiny bits.

Finally, buddy dropped by with 30ft of free unistrut as well... gave me a good excuse to throw this together: