1981 Oldsmobile Cutlass Brougham- my thread

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JasonL

Greasemonkey
May 8, 2012
105
4
18
Great progress on the car. You did a good job on the hood. Hopefully the new trans works out. I have the trans go shift kit in my 200 4r trans and it works good.
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
Thanks for the encouragement! I am just getting the seals I need for the TH350C and I hope to try to get that in this weekend. I am also getting new plugs (R44T Delco's) because the Accel header plugs are (IMO) crap- I have had them in for about 4 weeks, and already the electrodes are rounding off because the ground strap only covers half the electrode... I have only tried these once before with similar results. IMO they are a waste of money- $30+ a set, and they seem to run worse the longer I drive my car- and I have only about 350 miles on them.

Once I get the plugs changed and trans in, I am going to start tuning from square one again. I think my primary jets in the carb are still a tad lean, as the plugs now are just barely tan after up jetting the carb, but I want to try the new plugs before I change the jets. I am going to put lighter advance springs in the dizzy and back down my initial timing so it starts easier, but gets full timing faster, and I need to adjust the rockers again, so I am going to take an old steel valve cover, cut the top off it so I can adjust the rockers while the car is running without spewing oil everywhere... After that, A lot of road testing is in order :)

I just want to drive the damn thing!
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
Well, Saturday I got the trans swap done again... Those Afterburner headers are awesome! I didn't have to touch the exhaust to remove the trans like I previously did! I dropped the Old trans, swapped all the outer seals (front pump, rear output, shift shaft, and pan gasket/filter), and installed the TH350C in the car. Everything went well, the trans seems ok so far except I have a leak at both cooler lines at the trans because I switched to AN-6 fittings with 3/8" hose on them, and I think the NPT taper is different on the fittings I used than the factory fittings (even thought I used ARP teflon sealant, they still leaked). While working on that, I swapped the Distributor back out with a known 'good' Streetfire distributor with one medium advance spring and one light spring so I can have less initial advance but full at a lower rpm, I dropped a 168 tooth flywheel in place of the 53 with a new starter, and fired it up. It runs through the gears fine on jack stands right now, but once I found the leak I unbolted the tq converter to try to tune the motor with no load on it. I pulled the valve covers and jammed cardboard by the outside of the heads to keep the oil in the heads, and re adjusted all the valves once the engine was hot. I got all them where I like them (zero lash plus 1/2 turn hot) and the motor ran good, but it was surging badly- had to jack the idle up to about 1150 to keep it idling, and it still stalled when I put it in gear. Now I know the motor is adjusted right, so the only last piece I had was the carb again. Even though I did a tear down, clean (as best as I could without a parts washer or solvent dunk) it still was running shitty at idle. So I grabbed an Edelbrock 750 (that I just pulled apart, cleaned, wd40'd and re-assembled) I got in a trade for a junk trans that was no good to me, and after adding the pressure regulator back on (Edelbrocks don't like more than 6.5 psi) It fired up and sat there and purred... I don't know why, but Edelbrocks seem to have the best idle and drivability for stock to mild cammed motors. Anything over like a 470 lift 110 overap cam, and a demon is in order... Once the motor warmed up, it sat there and will idle all the way down to about 750 rpm (with trans still disconnected mind you) so I have to tighten the fittings, bolt the TQ converter back up, and see how she runs now! I have to say with the bigger primaries on the 75 Edelbrock, the off idle throttle response is INSANE!! I have a 1" 4 hole spacer on it too under the carb. Seems to help a 350 with a 750 cfm since a 750 is a lot for a relatively 'stock' 350.

I would have got more done this weekend, but I had to take my wife to the Hospital at 2 am because her wate broke- so at 4:43 am on Sunday I welcomed my second child ( a boy!!) into the world! He was 2 weeks early, but as healthy as can be, and we are home now 'enjoying' a 2 1/2 year old and a newborn :) we'll see ow slow the progress is now... Luckily most of it is done.

I can't wait to test drive the car!
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
Well, my fears were realized... When I put the new AN fittings in the holes for the cooler lines, I cracked the case. Damnit... I put the originals back in with some Permatex #2 and the leak was less, but still leaked... so the next plan of action is to pull the fittings back out, JB weld them and put them in, and hope it doesn't leak. it it still leaks, i will have to pull the trans and have it welded unless someone else has a better idea? I do have the fall back of taking the pump out of the trans i just had in my car and put it in the known good trans that the pump gear sheared off, and hope that works for now. My wife just had a baby boy on sunday, so money will be dry for a while since she is out of work
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
well, what I ended up trying to fix it was, I took the fittings out, wire brushed the threaded holes in the transmission and cleaned them with brake clean and a lint free rag, washed the outside of the case, and used some straight thread fittings (versus an NPT) and JB welded the threads on the fitting before I put it in, then threaded it in as far as it would go (which was further than the NPT) so I am hoping that the area where the taper would be would fill up with JB weld, and hopefully plug the crack. I am pretty sure the tip of the new fitting made it into the trans where it is not cracked, so hopefully when I put it together tomorrow, it will not leak. It has been drying for about 30 hours now, so by tomorrow, it will be all dry.

I will let you know. I want to drive my car again!! If this fix doesn't take, I will be taking a good pump out of one trans and swapping it into a trans with a bad pump gear but otherwise drove fine. We'll see how that goes. I may just drop both those transmissions off at my buddies hotrod shop, and let him have at it. That way, someone with actual experience can look at it.
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
well, the Epoxy fix did not work. The epoxy almost closed off the holes in the trans when I threaded the fittings in and it didn't leak for about 10 seconds till it built up enough pressure to blow through the epoxy, and then it leaked just as badly as before.

So, I took the pump out of the transmission that slipped, put it in the transmission that was in my car when I bought it (that had sheared off pump keys), swapped my tunable governor in, put my good vac mudulator in, changed the filter, and dropped that trans in my car saturday. With a full belly of fluid, the car drives great!- with one exception... It slips on shifts only- like it will rev up normal, shudder/slip as it shifts, revs up fine, shudder/slip on shift (only on moderate accel though). if you mat the gas, or manually shift, no slips. So I am not sure if it is an adjsutment problem, governor issue (cause it has lighter springs and weights than factory), or if it is low on pressure. For now it drives great - I have an Edelbrock 750 performer on it now (the demon needed to be professionally rebuilt, has a blockage or something) and it idles fine, has a ton of power, but is rich so I may need to do some tuning with metering rods and jets.

I am pretty happy with it for now, gonna have my hotrod buddy drive it and see what he thinks.

I gotta get the tires balanced, front end aligned, and start working on tinting the windows and putting the interior back in.
 

GT_80

Greasemonkey
Apr 23, 2013
240
7
18
Massachusetts
well, i have great news! I did a bunch of reading and figured even though my vacuum modulator was new looking it may be junk, and even though I used 1/4" fuel line for the vacuum to the modulator, it may not withstand the vacuum pressure from the motor, and the detent cable was not adjusted right.

I previously thought that the detent on a TH350 was not necessary. that it was merely for downsifting and did nothing else (mainly I thought this because I never hooked it up on my pickup and never had any adverse effects that I was aware of) -however I learned that the detent, when properly adjusted, booste line pressure when you are on the throttle which aids shifting and prolongs the life of the transmission. So I figured I had better get it setup right.

So I started by adding a 1/4" hose nipple to the back of the Edelbrock where it has a 1/4' npt plug. Then I made a brand new 1/4" steel brake line to route from the carb to the modulator. I bought a brand new modulator from NAPA Friday (Red stripe adjustable part number 1-7499) so I installed that next. Then I moved my detent cable back on the adjustable bracket I have so that when the carb is at full throttle there is only about 1/8" of pull left in the detent. I started it up, and took it out for a test drive. At first i slowly accelerated to try to mimick the behavior that made it shudder on shifts. No shuddering. So I nailed the throttle, it downshifted as it should then shifted to the next gear at about4500 rpm which will be perfect for my motor. Seems that by taking a few minutes to further tune my car, it was well worth it! The modulator was about $15, the steel line was $4, and the nipple I had on my shelf already. Hour or so of tuning saved me a lot of trouble!!! We'll see how the transmission lasts from now on, but I have my fingers crossed.
 
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