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General Buick Tech / Have Had Lots of Troubles with my New Engine/Trans Combo 2004-R

« on: November 03 2020, 11:23:05 PM »

Lots of Troubles with my New Engine/Trans Combo
Greetings all,

I am a new member this is my 1st post.

I am here with you guys because no one should know more about 2004-R's than you folks, but mine is behind a SBC V8 and I am having difficulty figuring if I have engine issues or trans issues. But most certainly at least some of both?

If you want a good read go over and check out this Forum for all the background to my woes, sorry its super lengthy but very informative: https://www.stevesnovasite.com/threads/help-diagnosing-performance-crate-engine-runs-ok-but-fairly-stock-bottom-end-mid-and-peak-power.673177/page-3#post-5902418

I have been through the ringer trying to get this right and need a good solution without dumping tons (more) cash, and ideally not tons (more) of time.

The car does well off the line but then you can barely tell it hitting 2nd and so on despite being a fresh build with a shift kit. Basically a soft mushy hit of 2nd, and early, at like 3200RPM. Seems to bog or be low on power, but also a better shift may help even that feel better. Engine is a 350ci in a 72 Nova, 3.42 rear.

The 2004-R was out of a 1991 Caprice, I think. Got it out of a junkyard since I just wanted to have it rebuilt to go in the place of a TH-350.....teh OD of course. I only needed a cross-member to do the swap, drive shaft was still fine otherwise I may have done a 700 or something else, but that takes a cross-member and shaft, etc.

I have tried 2 carbs (The link to that forum chronicles my search of the engine for issues, carbs was one suggestion).

1) 1st carb, a Holley 670 Street avenger vacuum secondary with the Sonnax kit for the TV to add to the throttle arm as well as the bracket to hold the throttle and TV connections to the rear bolt of the carb. At full extension I was getting about 1.100" @ WOT.

With this arrangement I got the following pressures:
PND3@idle=60, R@idle100, 2&3@Idle 157

Then holding TV cable full extension (TV cable disconnected from throttle so that the car can still stay running at 700-800RPM idle) the trans read pressures as follows:
PND3@idle=155, R@idle=250, 2&3@Idle=160

2) The 2nd carb on it now is a Quickfuel SS650. This carb has the TV spot built into the throttle lever, so it needs no converter kit. I also still used the bracket to hold both throttle and TV connections to the rear bolt of the carb. I think its even less firm of a shift to 2nd with this carb despite being a mech secondary. At full extension it was giving 1.400” @ WOT which matches the Sonnax suggestion better.

I have not double checked my pressure readings for this 2nd carb since it had the preset throttle arm I thought I was good but it is still soft shifting, actually I think even softer just when I thought that was not possible.

Again you can see this forum where I have been trying to chase engine power issues coupled with how this trans just does not seem to perform well: https://www.stevesnovasite.com/threads/help-diagnosing-performance-crate-engine-runs-ok-but-fairly-stock-bottom-end-mid-and-peak-power.673177/page-3#post-5902418

Trans has a 2k converter and I got a 2800 converter I just ordered but have not yet installed it.

No idea about the 2004-R governor I have, I expect in the long run I will need to modify it to shift later than around 3200 RPM. Open to suggestions on shift RPM and what exactly to do to the governor to get that with the least drops of the pan. I did have it out to get my speedo internal gear right, I know it has at least 1 spring in it, might have 2 but I forget. Didn't realize at the time that that mechanism affects shift points or I may have guessed and checked without a spring to get this project going since surely it needed less spring than a 91 Caprice.