Gearing questions 7.5 rear

[Stupidquestionspro]

I wondered what that dead spot is in the rpm range.

Also I’ve been having issues getting my kickdown adjusted just right unfortunately. If anything I have it adjusted too loose and that’s why it’s not kicking down.

The wire on the back of the factory tach is still there but it is not a resistor just a tiny piece of wire.




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[hoffa65]

I wondered what that dead spot is in the rpm range.

Also I’ve been having issues getting my kickdown adjusted just right unfortunately. If anything I have it adjusted too loose and that’s why it’s not kicking down.

The wire on the back of the factory tach is still there but it is not a resistor just a tiny piece of wire.




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since your speedo is right on I ran the numbers thru the RPM calculator I posted before, if that was a second gear pull (I think it was) every thing is right on the money, 65MPH=3100 RPM with a 2:41 gear and the trans in second gear. It just dont sound like it has any balls. I dont hear the vacuum roar of the intake, are the secondary's opening up ? have you check to be sure the throttle is all the way open 100% when the pedal is on the floor? 30 MPH in 13 seconds is just crazy, I think my 79 260 motor with 120K on it did better then that LOL

What heads are on this motor?

 

[Stupidquestionspro]

Well it wasn’t from a dead stop it was from a roll so it could have been second gear.

It’s a 68 350 block with #5 heads bored .30 over though when we had it rebuilt we had no idea about the compression loss with newer cast pistons which is what I believe it has so the compression is super low.

It has an Edelbrock 7111 intake and summit 600cfm carb the secondaries are vacuum I believe and I think they are opening. From what I can tell the throttle cable is pulling the throttle all the way open but my throttle cable is messed up and I’m working on swapping it for a new one.

I know for a fact the trans shifts twice and I know it will shift into all gears from manually shifting it and manually downshifting just to check.

My kickdown may be messed up I’ve been fighting issues getting the kickdown to actually work for a while.

I’ll have to do another vid from a dead stop.


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[olds307 and 403]

Your low stall won't be helping launch but it may have carb issues. Your timing should be close. What are you currently running for vacuum advance? It is hard to tell with the rpm, depends a lot on the exhaust. Buy a cheap tach and compare the rpm. Yeah, 2.41 gears and a 1700 stall don't help at all. My 70 Cutlass S is no hell with it's 1700 stall and 2.78 gears. I just bumped up the timing from 14 or 16 to 20-21 and man what a difference. I believe I set the mechanical advance to 18 as well. So I should be around 50 total with vacuum advance, set at 12 I believe. But my Olds 350 is 9 to 1 compression. My 88 with the Olds 260, I checked the timing, final got a marker back on it. My dial back light needs fixed. The little 7.5 to 1 260 had to be around 35 degrees at idle. I retarded it, I bet it was 40+! I went it between that where it was hitting the starter and where I put it around 35 originally, runs better in gear at idle. I should have put the 2200 to 2500 stall behind it, flashed at 2300 stall behind my 350. With the Sanderson shorties, 2.5" dual X pipe exhaust and 3.42 gears, the 260 has acceptable performance and sounds great. I miss the 2200 to 2500 stall a lot and will be going to back to one on my 70S.

 

[Stupidquestionspro]

My MSD came with the vacuum advance set no adjustment on the can. I have it running to the timed port on the carb it hated full vacuum like some recommended.

Yea may be carb issues my carb is only a few months old but I will say I’m having the hardest time adjusting it makes me miss computer controlled systems I am way better with those this is my first serious time with a carb and it’s whopping my *ss.

The stall and gearing I’ve never been a part of so I have no idea before my dads disease got to him he always handled everything gearing and carb related I only did bolt on and off with that for the most part I handled anything computer controlled or computer programmed and wiring. Unfortunately years of being away from the industry and the toll the disease took on his mind and he has lost his touch and makes quite a few mistakes so I’m trying to teach myself rather than constantly proving he’s losing his skills


This is the tach key off

Tach with the key on

Tach engine idling in park

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[Stupidquestionspro]

Ok new videos and just for info prior to the videos I did put on my new throttle cable and while I’m pretty sure it allows full travel I’m not positive and I’m hoping the pedal isn’t bottoming out prior so I’ll have to check

WOT from a stop

driving through my neighborhood

I didn’t get a video but on the way back I manually put it in first and ran it to like 4500 and it was like there was a dead spot where it stuck around 3k but suddenly it got past it and started pulling hard all over again ended up almost 45 mph in first gear.


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[olds307 and 403]

I am surprised it hated manifold vacuum, my 8 to 1 Olds 350 and 403 with the 204/214 cam liked it. Looks like it puts out 16 degrees of advance which puts you at 56 part throttle which about right. A carb is guess work, I bet it is too rich out of box. Most are set up for 9+ to 1 sbc 350's with some cam. Only and Air/Fuel meter will tell you for sure but you can read the plugs but choke setting and timing will effect that as well. Where are the automatic shift points on the tach? Not sure on a base TCI but stock are around 4000 rpm.

 

[Stupidquestionspro]

Well from what I read the TCI has a different first gear of 2.75 but shift points seem to vary based on load in the WOT video it seems to be around 3500 rpm


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[Stupidquestionspro]

Manually shifting through the gears after I adjusted the shift cable it was on the second hole not first like the instructions for B&M said though didn’t seem to make a difference.

So it is seeming someone changed gears or my tach is off which is strange considering to my ears it sounds about like the RPM the tach is showing

And I triple checked the axle the code is 2AJ for sure.


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[olds307 and 403]

Until you get another tach or open the rear end cover, you won't know for sure.