Hot Rods RPM's too high on 700R4

If by "a little over 20 years" you mean 35 years, then I agree.

The more I read, the more I'm convinced the tachometer is configured wrong. Pump gas street engines rarely idle over 1000 rpm. OP, have you checked this? If it's set to a 4-cylinder configuration, then it explains everything else you've described: the tach is reading double the actual RPM.

 

Big tires, 820x15's will give you about 10 mph faster at the same "RPM".

 

We are only mentioning a tachometer because it’s mentioned in the opening. I guarantee I would know an engine running 4000 rpm at freeway speeds and Rick in his first past says it shows 4000 on his tach but he doesn’t say his engine is loud AND he’s not going at least 150 mph. I’m starting to this is all BS or it’s April fools and I’m starting to think I know who are the fools..

 

Why are we talking about 700R4s ? I'm sure Street Rod magazine has lots of articles about making them work.... But then again I did catch shit about my TKO 600. But at least it has 3 pedals....Sorry in advance , Lumpy.

 

Ask the Great Wizard ......

 

Ha, ha. Not an April fools and not BS. I didn't grow up a motor head and am new to all this so bear with my ignorance. I've never owned a hot rod (until now) so never really had to pay attention to tach readings. I'm quickly gaining an education. Here's an update. I did check the settings on the tach and some of you who said it sounds like it was set at 4 cylinder were correct, it was. When I set it to 8 cylinders, sure enough, it dropped to about 550 RPM's.
I am running the Edelbrock adjustment bracket, but the geometry still seems a bit off. I'll let the tranny guy figure it out. I think I've got it close, but it's not worth it for me to "think" it's correct and gamble at getting it right when I can have a professional "know" it's right for hopefully a lot less than a rebuild.
What this is in, btw, is a 1948 International KB1. I started on this project 3.5 years ago and didn't know anything mechanically or body work but have done all the work on it myself. We all have to start somewhere, right. Thank God for Google and Youtube.

 

Your truck looks great.

 

Glad you found it. It would have been my first check but I’ve been a motor head for 60 years. Good luck with your trans settings,,

 

We all learned this stuff and some point, none of us were born knowing any of it. Good for you for following through with this!


Sent from my iPhone using H.A.M.B.

 

I'm so glad that this site exists. Everybody's input is really valuable and makes tackling a project like this a lot easier when us newbies can lean on folks who have been down this road before.

 

Bright side... It was super easy to fix!

I'm glad you found it and you did not have to pull a transmission in the process. Keep learning!

 

Ain't hot rodding fun?!! One tip - don't use the TV cable to try to adjust shift points. That will quickly ruin the box. Set it at the correct setting and forget it. If you find you need to raise your shift points (common problem for hot rods. It is easy to raise shift points by removing weight from the governor. I have only done it on 200R4s but it has to be the same for 7004Rs. Biggest difference I reckon is that the 200 governor is accessible outside the tranny while the 700 requires removing the pan. Governors are surprisingly cheap. I found an internet source for $12 for 200s. I bought several and experimented 'til I found the right weight removal.

Here is what my 200 governor weights needed.

ground one, marked for grinding on right.


Marked one on right, ground one on left

Removed this spring for a little more RPM.

Brazed in a small nail to capture the remaining spring. Reportedly they pop out at times.

 

I like that old IH truck, actually pretty stylish and unless appearances are deceiving, you've done a nice job

 

You’re right about the governor and the shift points. I might be foggy after 25 years, but the early 700 I had the governor came out the side, not the pan. In those days you could buy “kits” with weights and springs to change shift points. They were “approximate”, took more than one change to get it right.

Nice truck, way better first effort than mine.

 

I think you are right. thec200s are in the pan, the 700s are outside. Either way, its an easy task and worthwhile.

 

Did you ever think about the fact that we use a device invented to keep steam engines under control to control a modern hydraulic transmission?

 

200 4r governor in the pan. 200 3 speed , in the rear, outside,..along with the 700 R4 and TH 350 and 400
The brazed in nail is to keep the spring in place during a burnout. Sudden change in RPM causes the problem.
If the cable corrector is the right one, then a lagging 3-4 shift can be corrected by taking a couple of clicks out of the cable adjuster. I said a couple..Anything more..you should have a pressure gauge hooked up.

 

For the love of all things holy, please tell me you are going to put the fenders back on and get some different wheels?

 

I’ll bite. Can you explain a bit more?

 

I think he's talkin' about the governor, Governor.............

 

Balls Out!


Sent from my iPad using The H.A.M.B. mobile app

 

LOL - Yes, fenders are going on. Just waiting until I get the transmission business figured out. Much easier to work on this way than leaning over those fat fenders and run the risk of scratching it. The rear fenders are on. This is an older picture. As far as the wheels. My goal is to put Cragar wheels on. I just have to wait until my budget allows it. Also, these are 14". I don't like the look of the smaller wheel. Will be going with a 15" when I go to Cragar rims.

 

Shift points on the 700R4 are adjusted by using different weight springs on the governor. There are kits with different springs that are easily changed by simply removing the governor cover and swapping springs. B&M sells a kit with a half dozen springs for this.

https://documents.holley.com/20248.pdf

 

Good to hear. Keep at it.

 

On a 700R4, shift points are in fact affected by the TV cable adjustment. The TV cable and the governor work together in yielding the shift point at various throttle positions and speeds. I have read so many times the absolute false comment that if your TV cable is out of adjustment it will ruin the transmission in no time. Of course taken to the extreme if you disconnect the cable and floorboard it, you're going to have some trouble, but if it's somewhat out of adjustment you will just have real weird and crappy shifts.

 

Hats off to @silent rick. You named that tune in 7 notes! (posts)

 

With a 700 the tv is for maintaining proper pressures in the transmission only. It is the only GM trans that has a tv cable instead of a kick down like the 350, 200 etc. In that respect it is just like a mopar transmission. Improper adjustment will cause slipping of clutches or excessive pump wear.

 

Modern transmissions use a speed sensor. The flyweight governor hasn't been used in 15 years or more.

 

Bingo! Yes, the TV cable does have some affect on shift points, but should not be used to adjust or correct shift points. It's adjusted to correct pressure on the clutches and trans only. The governor and springs adjust shift points.