73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: TexasRed on January 31, 2011, 08:44:49 pm
-
Ok. Here's the skinny:
Engine: 383 Chevrolet with vortec heads, edelbrock performer intake and their 8032 throttle bracket. I used the throttle bracket to hold the TV cable and the throttle cable didn't want to reach to the carb. I think the bracket is too far back. So I modified a bracket that fits on the back of carb for the throttle cable.
Carb: 1980 Qjet that should be calibrated for my engine, are all Qjets ready for the 700r4 TV Cable? I've read somewhat contradictory information on that. It's on a one inch plastic spacer with a 1/16 gasket between the spacer and carb and a 1/4 inch gasket between the plastic and manifold.
Problem: It doesn't upshift to 2nd when it's supposed to and subsequently holds 1st too long. I've adjusted the TV cable twice, by pushing the tab and then the housing back to the bracket and then WOT under the hood. Should I try pulling the cable out a little more? Maybe I'm at the end of the adjustment on the cable and should get a bracket that's closer to the stud on the carb?
-
are all Qjets ready for the 700r4 TV Cable?
There are differences in the total carb movement "idle to WOT measurements" between one meant for a kickdown cable from a TH350 and one meant for the 700R4 TV cable. I ran into that problem on a truck a while back. One more reason I don't like automatics but that is a whole other story. I am sure others will chime in...
-
What I've found through trial and lots and lots of error is that anything that messes with the original geometry is not going to be right, no matter what adjusting on the cable that you do. Aftermarket intake, carb spacers, etc. will change your geometry relationship to the bracket. As far as the q-jet, mine had no provisions at all for anything but a throttle cable, since it was originally equipped with a manual. What usually works in a situation like this is VileZambonie. ;)
-
Well I don't quite recollect, but I think the transmission didn't shift at all. It did before the carb swap, so I'm going to try to see if I can pull on that cable a little to get a little more slack and try that. Otherwise I may have to move the whole thing forward.
-
http://www.cpttransmission.com/tech_tvcable.htm
Take a look at the diagrams for proper geometry.
Same stuff here:
http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html
The mid-80's Q-jets definitely had the proper linkage and you can swap out the throttle shafts. I was unsure whether the Q-jet I'm rebuilding (a '79) would have the proper geometry for a 700R4 and it does according to the above links.
BTW How does your 383 run? Wishing you had gone with a bit more cam? Did you hit any other snags after the whole connecting rod ordeal?
-
It's running good. Haven't had a whole lot of time to put miles on it. I need to switch out electric fuel pumps. No other snags really, had to put headers on it and as the 305 exhaust manifolds had a bolt hole in the wrong place. So now it's got long tubes on it, no biggie. Just a few bugs here and there to shake out. May get it to Giddings this weekend for a small drive, but it kinda needs new tires since the truck was sitting for a few years.
Update: I forgot you asked specifically regarding the cam. I know I'm prolly leaving some HP on the table, but it seems to be a good cam that I got. I may wish I got more cam later, but I think either way I need to numerically increase the rear end ratio.
-
The TH350 distance from the center of the throttle shaft to the center of the pin for the kickdown/TV cable is the same as the 700R4, so they can/do work. Your best bet is to use the bracket that bolts to the carb & not the manifold since you have the spacer in there. I have mentioned in other posts...this whole deal has to be right (stiff, arch, ect.) to work properly. I've even altered the stock bracket due to variations in the replacement throttle & TV cables to achieve full throttle once or twice. Your problem may not be in the cable, Transmission?
Can you post a picture of your set-up...maybe something will pop out as a problem. Does your TV cable have any ridges where it slides to the backside of the bracket? Post up a pic & we'll try to help. Lorne
-
Update: I forgot you asked specifically regarding the cam. I know I'm prolly leaving some HP on the table, but it seems to be a good cam that I got. I may wish I got more cam later, but I think either way I need to numerically increase the rear end ratio.
Glad to hear you're happy with it. I wasn't suggesting that you left too much hp on the table. In fact, IMO for any street-only engine HP means "nada" (even in something like a Z06 or a GT500). I was just curious if you are satisfied with the torque curve and if it ended up with a enough mid-range grunt to make you happy.
Back to your 700R4: It seems that you should set up your TV cable geometry (relationship between the carb and mounting point) first and then find some other means of adjusting the throttle cable so you can achieve WOT (shorten cable, aftermarket cable, bend pedal rod, etc). Did you compare your setup to the diagrams in the articles I posted?
HAULIN IT: What carb mounted bracket would you recommend? Most of the ones I've seen look flimsy like they would flex. What bracket setup were you last using with your 700R4 before you swapped to a 4L60E?
-
I used the Holley 20-95. It's pretty strong.
-
event: I did stumble across those pages. . . I think if my carb seems to have the right linkage, it should give me the right dims for the pull.
I'll try to take a picture of the setup, tomorrow, as it's like 27 degrees right now. I would have worked on this sooner, but I got a job interview and a staffing agency interview (disappointing about Austin :( )
The 20-95 holley bracket works with the quadrajet?
Thanks for the help guys!
-
The edelbrock bracket is almost perfect for my throttle cable. There's some slack with the Mr. Gasket bracket. I only need like a quarter inch with the edelbrock bracket or somehow take up the slack with the Mr. Gasket bracket. I think I got another click outta the TV adjuster, but that thing may be at the end of it's adjustment.
A couple of pics:
(http://i57.photobucket.com/albums/g207/hippiegohome/P2050094.jpg)
(http://i57.photobucket.com/albums/g207/hippiegohome/P2050093.jpg)
-
Seems like that Mr Gasket bracket isn't gonna let you get close to WOT with that much slack. That is important for proper TV cable adjustment. The Edelbrock bracket should simply pull the "at rest" position of the accelerator pedal a bit higher. If the accel. pedal rod (in the cab) is hitting the firewall before the cable can reach the carb, something isn't right there, because that bracket looks very close to a factory bracket in terms of distance from mounting point to carb stud.
And yes, that TV cable seems to be pulled nearly all the way out. Make sure it does still have another click or more of adjustment. If not, you've most likely found your problem. If that is the case you'll need to either modify the Edelbrock bracket or go with a sturdy carb mounted bracket like HAULIN IT suggested. No, a Holley 20-95 doesn't look like it'll fit a Quadrajet without modification.
Here's one I found for the Q-jet:
http://www.summitracing.com/parts/TCI-376700/
But I would try modifying the Edelbrock bracket first. It looks like a decent piece.
-
It did have a different combo on there, so someone may have adjusted the throttle cable. Is that possible to do in the cab? I think I need to get something different for that TV cable, it's just too far away. I guess I could get one of these too and cut it to length:
http://www.jegs.com/i/Mr-Gasket/720/5657/10002/-1?parentProductId=1358571
-
You can get a little more throttle travel by bending the pedal rod like I had to do. Do you need the 1" spacer as an adapter or could you ditch that and bring the carb down to a closer to stock location?
edit after looking at the pic again: But you can't get THAT much slack out of it just by bending the pedal rod alone.
-
Get the carburetor mount bracket. Autozone carries the cheap universal one that works just dandy.
http://www.autozone.com/autozone/accessories/Spectre-Throttle-cable-bracket-with-automatic-transmission-kickdown-May-not-be-legal-for-use-on-pollution-controlled-vehicles/_/N-25y2?counter=1&filterByKeyWord=throttle+bracket&fromString=search&itemIdentifier=228260_0_0_
-
At first I thought that was the same as the mr. gasket, but it appears to be MUCH more adjustable. I'll try that in the morning, after I replace my vw rabbit's battery. >:(
Thanks again guys!
-
Hmm, well, checking summitracing.com: http://www.summitracing.com/parts/SPE-24283/
I have to buy an extra part to make it work for a 700r4. :(
-
Tex, After looking at your pictures I agree with the idea that it seems as you would have a bunch of slack in your throttle cable (pedal laying close to the floor) with it hooked up. I realize it's not in place in your pictures, however it looks as though it's running uphill from the bracket to the carb. This needs to be close to a straight line. Maybe you could add a plate with the bolt holes to raise the upper portion to make it straighter. I've never been a fan of the adjustable ones that Vile posted, too weak & too many things to work loose, ect.
Event asked about the bracket I've used. The one on my truck is a modified version of the GM flat one that bolts to the carb only. It did not allow full throttle originally. After the cutting & welding, the offset is very similar to your Black bracket. It is now just used for the throttle since changing to the electronic trans, however the 700 worked great with this bracket for several years. After needing a new throttle cable I found several lenghts of cables that were supposed to be the same/correct...I'm not talking the total, the cable portion compared to the jacket. I believe this could be some of yours & others trouble with it working out right. If I held the carb end the same, the other end was 1/2" different. When I bottomed out the jacket toward the carb end, the cable & jacket was a good 1/2" shorter on the one. I "fixed" a similar problem on a friend's vehicle by cutting a slot on one of the flats of a small nut & slid it over the cable between the pedal & the crimped on end (shortening the total of the cable).
Hope this helps in some way, Lorne
(http://i163.photobucket.com/albums/t285/HAULINIT/700R4bracket001-1.jpg)
(http://i163.photobucket.com/albums/t285/HAULINIT/700R4bracket002-1.jpg)
-
Hmm. Well it looks like I may hit the junkyard today. To run the 700r4, I have to buy that extra bracket and I can't seem to get that local without paying and waiting the same as if I buy it from summit. Looks like summit may sell a similar one under their one name. . . .Hmm. . . If I had a welder, I'd agree with you regarding modifying something a bit firmer than the adjustables, but since I do not. . . .
Oh and thanks for the picture, it all helps.
-
I still say you can modify that black bracket to work for you. Looks like it would just be a matter of drilling two holes after you figure out where you want it. Should be easy to get both cables moved toward the carb .25"-.5" It's free and you can do it in minutes, so it's gotta be worth a try.
-
http://www.summitracing.com/parts/EDL-8032/
I don't think that bracket leaves a lot of room. I may get .25". Heck, let me take everything off and try.
-
Update: I'm close!! A friend drilled a new hole and that seems to work. One more click on the ole adjuster and away I went. I need to drill another hole as the bracket will move if pushed around. There's a teensy bit of slack in the throttle cable now, but that should be ok.
-
Just make sure you can reach WOT before the accel pedal bottoms out on the floorboard. Then readjust the TV cable.
You asked earlier if you can adjust the effective length of the throttle cable from in the cab. Yes, as Haulin It described above (in case you didn't catch that). Lift the accel pedal up to expose the steel cable where it meets the top of the pedal rod and check for shims or other modifications made. Maybe post a pic.
-
Actually, most of the little slack that I had was taken up I think when I set the mixture screws to 2 turns out. It's weird, I can keep screw the mixture screws out and the idle keeps going up which I have to reset to 700 or so. Anyway, I set it back to 2 turns, and set the idle to 750 rpm. It's a lot better now. It shifts at 15-20mph and then it seems to downshift when I hit WOT too.
Also, there's 2 vacuum switches under the hood, one looks like for the distributor delay and the other the TCC? The delay is on the left and the TCC one on the right? I think I can get rid of that distributor thing because it's an accel distributor.
-
My TCC vac switch is located near the power brake booster. I have the vacuum line for it running through a thermally operated switch and then to the ported vacuum source.
What is the "distributor thing" currently hooked up to?
It's weird, I can keep screw the mixture screws out and the idle keeps going up which I have to reset to 700 or so.
Maybe you could benefit from drilling out the idle mixture screw holes a bit?
Do you know what the specs are on your carb for all the restrictions, bleeds, etc.?
-
The distributor thing is hooked up to wires that go into the cab. I'm thinking it works in conjuction with ESC.
Well, I may try adjusting the mixture screws later, it seems to run well here. Very smooth in the cab at idle but I can hear the exhaust (headers and glass packs don't help). I don't have the settings as the carb builder kinda holds those close to his heart. I could drive the truck to where he's at and he'll redo any settings using that 4 gas analyzer. Hmmm, I may be able to swing it into get some fishing done too.