Josh's Syclone build thread

syclone0517

Member
Well, the trans has been taking a bit longer than usual but my buddy is really putting in a lot of time to make sure we get it built up right this time. Unfortunately, he is having to fix someone else's work. If it was just a stock untouched trans this whole process would have been a lot faster and also probably only would have to be built up once. But, it appears the trans shop in Phoenix that built this thing for the previous owner did some stuff that isn't kosher. I am not a trans expert but my buddy has been showing me some things along the way and will update on this soon. In the meantime, we did get Sports Machines kickdown cable repaired. As previously mentioned, we cut the end off that goes in the trans, and adapted a piece to it that allows 360 rotation so that you can make sure it is not in a bind when stabbing it into the trans and then you can lock it down with the nut in the photo. I have been trying to tell Sports Machines that the end is crimped on 180 degrees off but I don't think they seem interested in investigating this more. It is a reproduction unit since GM doesn't make the cable any longer. At any rate, we will give this a go and hope the end doesn't warp like it did in the previous photo I attached (actually warped twice, this is my second cable).

I also took the time to smoke the intake manifold and fix a leak I found at the IAC valve. I have a base level tune uploaded courtesy of WyoSyclone with the 50 lb/hr injectors installed. We will give that a shot and try and tune it from there. He had also suggested I get the wideband running through the factory ECM so that we can datalog it so I took care of that. Oh, and I upgraded the trans cooler too since the one it came with was only a 4 pass unit. Hopefully, she will be running good come fall and winter here in Texas so that I can beat on it when it is nice and cool outside. Looking forward to dyno day and track day.

View attachment 1863908View attachment 1863909View attachment 1863910
View attachment 1863912
Have you looked at Lokar kick down cable kits? https://www.lokar.com/assets/instructions/INS0036-GM-Kickdown-TP.pdf
 

Goodgollyjosh

Active member
Syclone0517, I will be looking at Lokar for a soft diptstick tube since I don't imagine my 700r4 stock unit or the one that came with the TH350 will work with the tight confines of the Syclone. I was unaware that they make TV cables, good to know for the future. I won't be using a cable with this TH350 which is why I wanted a manual valve body, I'm frustrated with TV cables at the moment lol.

Bob, I used a cut off wheel on an angle grinder and then I chamfered the shaft with a grinding wheel and then filed all the splines to make sure it stabs nicely into the transfer case. I would have preferred to do it on a lathe but that would have required disassembling this trans and I didn't want to do that. The shaft didn't get very hot, I kept an eye on it, never even really blued at all. I meant to snap a pic of the shaft before I left for work but I forgot to. You can kind of see it in one of the pics below.

I finally got the adapter and the Syclone tailshaft housing bolted up. I had to get longer bolts, the studs that came with the adapter kit weren't long enough, they are for a regular 700r4 tailshaft housing. I pulled the pan off today just to make sure everything was clean inside and it looked good so I bolted it all back up.

Been working on the shifter too. Finally got it shimmed up properly to retain all stock center console components including the leather boot. Now time to make some brackets and bolt it in place. I am obviously sacrificing the center console support to do this but it was either that or drilling holes in the floor of the truck which I didn't want to do. I figured easier to find another center console support if need be than to find another cab or floor pan/trans tunnel or weld up the holes in the floor. Will post pics of that set up when I have it all squared away.

trans outfitted, resized.pngpan off, resized_LI.jpg
 
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proptop

Donating Member
Josh,
Looks nice and it has the aftermarket bell housing which is a huge safety factor/deal. You are going to like the first gear in that thing too.
Bob
 

Mikeysy15

Donating Member
Like Bob says , you’ll like the longer first gear . Once you start going fast that first gear is too short and actually hurts your 60ft. I was shifting into 2nd gear before the 60ft when I had my 700r4 in there . 1st gear was a waste of time even on the street .
 

Goodgollyjosh

Active member
Thanks for the kind words Mikey. Also, good to know I am headed in the right direction. So...how bad will it be on the freeway at 80mph? Screaming it's head off?
 

Mikeysy15

Donating Member
Lol. I have 3.08’s and a 28 inch tire on my truck . I’m doing 75mph at 2700rpm so I would think you would be somewhere between 3400-3500 with 3.42’s and a 26 inch tire. So ya you’ll be turning some rpm .
 

Goodgollyjosh

Active member
Well, I did a test fit of the bell housing in the truck and I need to cut off the ears for the dual bolt pattern. The ears are for Oldsmobile and they are in the way, it simply won't go in. So, I will trim them off tonight. It looks like the previous owner of the TH350 must have had the same idea because somebody started cutting one of them off already.

In the meantime, I installed a pencil shift light in the cigarette lighter and mounted the control box in the glove box and simply Velcro-ed it to the ECM. I can see the shift light pretty good from the driver's seat. I thought it was a nice clean install and keeps the stock look overall on the interior.

bell housing and trans, resized.pngshift light, resized.pngautometer, resized.png
 

Goodgollyjosh

Active member
Trimmed the ears off the bell housing. It fits now but it's still a bit too snug. I need to make a small notch for the fuel lines. Oh, and i meant to include a pic of the trimmed tail shaft so I'll throw that in too.

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Goodgollyjosh

Active member
Finally, got some work done, been super busy with other stuff. The notch for the fuel lines has been cut in the bell housing. It finally goes into place nicely in the trans tunnel without hitting anything. I'm sure it will no longer pass SFI certification but that's okay, I don't ever plan on being fast enough to need it. I had some fitment issues with the torque converter, it wouldn't plug into the back of the crank but after I buffed off the paint that B&M applied to the snout, it went right in. Had to fix a few stripped out threads in various spots around the TH350, I'm sure the case is probably 40 years old or better, not sure I could expect anything else from aluminum that is that old.

Surprisingly, the aftermarket dipstick that came with the trans fit perfect in the truck, I was shocked. I'll upload a photo. Another thing that shocked me was that the crossmember bolted right up with the TH350 and the 1.750" spacer and the Syclone tailshaft housing. However, I did notice that the trans mount studs that protrude through into the center of the cross member are now sitting maybe .050" further back on the slots than before. Which means, I will likely have to shorten my rear driveshaft a little because I honestly didn't have .050" to spare, I'm not sure why but even when the truck was stock I always had a hard time putting the rear driveshaft in place, it just barely fits even with the truck in the air and the rear end suspended to full droop.

So for now, the trans is installed, hopefully it'll be in there for quite some time. I'm honestly tired of flat backing it with a trans balanced on a floor jack , it sucks, I'm too old for this shit. But, everything is tight and now all I have left is the new shift cable routing and adjustment. trans brake hook up, which I already did the wiring on a fused circuit, just need to hook it up, I need to have my buddy swing by the house, he always helps me stab the transfer case since we all know that it doesn't sit very nicely on a floor jack, and then some odds and ends and then time to test everything out. You guys have been a wealth of knowledge on this little truck and I appreciate all the help thus far.

dipstick tube, resized.pngnotch, resized.pngtrans left side, resized.pngtrans right side, resized.png
 
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Goodgollyjosh

Active member
Now that I will be shifting this thing by myself, I am curious what a good safe shift point is on these engines when running the stock internals?
 

Goodgollyjosh

Active member
Ok sounds good Bob. I appreciate it. Since this thing shares so many similarities with an SBC, one mod I use to do all the time was to get rid of the exhaust rotators and small springs on the exhaust side and just run intake springs and intake retainers all on valves for a bit more seat pressure. Not sure if guys are doing that on these engines or not. But, in the meantime, I figure if I shift it low enough it'll hopefully live for a bit longer. Just curious how tight do people turn these motors in stock form... 5500? Less?
 
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proptop

Donating Member
Josh,
I haven't looked at a LB4 head lately and can't remember if they had exhaust rotators on them. I believe they do. You could buy some big block Chevy ones and turn them down for spacers so you won't have to use two different springs on them. If it is a stock cam motor it might pull to 5000 rpm but I don't believe it will be making much power up there.
Bob
 

Goodgollyjosh

Active member
Thanks for the tip Bob. It does indeed have rotators. I pulled the valve covers when I first got it. The only aftermarket internal mod that I could see was stock ratio comp steel roller rockers. I don't need to rev the engine any higher than necessary. I will just shift it at stock shift point, whatever that is, I wish I had payed more attention, I think it was shifting at 5k or so.
 

Goodgollyjosh

Active member
Trans cooler has been remounted after I removed the barbs to install AN fittings. I cleaned it out real good after the last trans failure. I also looked up a TH350 oil flow chart and it looks like the lower cooler line connection is out-bound flow and the upper is in-bound so I made sure to feed into the top of my cooler for a small amount of gravity assist.

I had a crack in my center console lid so I epoxied it and sanded it down to respray it. I also took the shifter indicator apart to clean everything and polish the plastic, came out looking real good.

Lastly, took the driveshaft and cut half an inch off the slip yoke so that I won't have any problems installing it anymore. I still have 1" before the transfer case output shaft would bottom out inside the slip yoke so I should have plenty of margin for error. It still bottoms out where it was meant to bottom out, against the rubber stopper inside the transfer case which rests again the tip of the yoke.

cooler mounted, resized.pngrepairing center console, resized.pngdriveshaft trimmed, resized.png
 

Goodgollyjosh

Active member
Got the center console lid filly refurbished. After I sprayed it you can't even tell where the crack was. I oiled up the leather boot too. I used double zero steel wool to polish the clear plastic top for the gear position indicator and then polished out the little micro swirls left behind using some headlight polishing cream. It all came out pretty nice for 30 year old parts.

center console lid repaired 2, resized.png
 
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