Engine needs major tune-up

Hey guys. I recently finished upgrading the suspension of my 1970 Skylark 350-4 and feel that the car is ready for a proper tune-up. I'm currently in the process of changing spark plugs and wires and will finish in about an hour. My issue lies in the redline of the car. It is an automatic transmission and for some reason shifts at 3500-ish from first to second and 4k from 2nd to 3rd. Is there any reason why it shifts so early? I feel as though the car gets more and more power throughout the band, then as soon as it's about to unleash everything it shifts before it can get there. The car seems seriously underpowered considering the upgrades the previous owner did. It has a TA perf. stage 1 intake man (I believe it's a single plane, don't remember for sure. Will check later and update post), 4 bbl edelbrock carb, and a pointless dist with flamethrower 3 ignition. From what little I know about V8's (forgive me i'm still learning lol) this engine should be making high 200's to low 300's hp? What could be wrong? The engine has 88k original miles and sounds extremely healthy. Any information/help is extremely appreciated.

 

The carb is holding the engine back big time... swap to a rebuilt Q jet from one of the vendors here on this site and you will be super happy you did.

 

How could I find out for sure whether it is the carb or not? I was told the carb was high end. Once again, forgive me as I still don't know enough about carbed engines let alone a 1970 Skylark. That's why I got her.

 

Read Larry's "PowerTiming":laugh: Thread

 

Your leaving a lot of questions to be answered first. You should find out what trans you have. 350 or 400. 350 has a cable that goes up to gas pedal near firewall where accel cable goes to carb. 400 will have an electric switch on accell pedal and a wire on driver side of trans just above trans pan. You could be needing an adjustment for trans to shift later. I really don't think anything is about to unleash at 4000 rpm. You may me missing out on extended rpm range though. Chances are its overcammed and compression ratio/trans convertor/rear gears are not matched either.
Next find if it was originally a 2 barrel car . if so acellorator cable can be too short holding back carb from fully opening. Confirm vacuum lines are all in correct places. This can make trans shift wring also. The stage 1 is a dual plane intake. For a lower rpm range. Yes carb isn't the best choice more than likely too small also. A correctly built Buick 350 qjet is best choice. Check engine code on block between cylinder 1 and 2. Code will be like SP or SO or similar. This will tell you more about the engine. I also think you may need to degree cam but you will need to know what cam you have. Might want to contact previous owner. He kinda left you hanging with an unfinished project in my opinion. He never got the combo tuned right and lost out on the gains . the edelbrock carb is not high end. If your not an experienced carb tuner this isn't for you. Find out if trans convertor was matched and what rear end gearing you have along with camshaft.

 

Thank you everyone for all the information! There's definitely quite a bit I still need to learn. I'm glad this board exists otherwise chances are I wouldn't learn anything myself. It seems the next step is definitely a quadrajet and making sure the transmission is properly functioning. Would buying a quadrajet from TA and having them tune it be good enough? Should I even try playing around with one myself? I would eventually like to learn how to tune a carb. Also I'm fairly certain the cam is stock. The previous owner had a comp cam in a box that looked like it had sat for years. He gave it to me when I got the car. The rear gears are stock too, but he told me he installed a shift kit.

 

Get a qjet from quadrajet power.com or everyday performance. I seen mark at quadrajet power has a few carbs built already. Get the correct fuel line if yours has been cut. I would not bother with a comp cams cam. A ta 212 is OK for what you have if you plan to use headers. But the Crower level 2 would be abit better for lower end power without headers and stock gears. Or you can shave heads .060- .070 to bump compresssion to about 9.4/9.5 (about 42 cc chamber)get the Crower level 3 a 2000 convertor and 3.23 -or better gear in rear even a 3.08 would show improved response. Don't need headers with it either. Shift kits can alter shift pressure and could be the reason for it shifting early. If you have a 350 trans ,the cable that goes to pedal doesn't really have an adjustment. But you can add a lead fishing sinker to cable to pull cable out farther. Some trans shops did it that way . some would bent pedal bracket for cable

 

No changing the cam until everything else is in proper order. Even when he gave the cam with the car I had no intention of using it. I read quite a bit of info on this board before even buying this car so definitely no comp cam. Also I will definitely check out quadrajets from people right on this board. Once again thank you everyone. I appreciate all the help.

 

Did anyone suggest shifting the car manually to see how it does?? If it runs great shifting manually, then it's either the governor or the detent cable/switch depending on which transmission it is.

If it's not pulling hard to 5500 or so, then there is another issue. That will need to be solved first.

 

I tried manually shifting today. It pretty much capped out at 3500 in first gear. No difference.

 

You mean you were holding it in 1st gear with your throttle foot on the floor and it wouldn't go higher than 3500 RPM. Something is seriously wrong. Without going back and rereading your OP, do you by chance have an electronic conversion in your distributor with a rev limiter in it? If so, the limiter may be adjusted way low.

When you run it up in first gear, does it run smoothly all the way up or, does it miss, surge, etc.?

 

It actually runs very smooth. If I didn't know the redlie should be higher I would have assumed that's just how it is.

 

I'm thinking there is a fuel problem but further testing needs to confirm that. But the edelbrock needs to go in my opinion. But that's not the problem. Should go past 3500 even with it. You mentioned flamethrower ignition. Is that just the coil or distributor also?. Could be a bad coil. Been reading a lot of performance coils seem to be subpar. So its something to test for.

 

You mentioned in your OP that you have a Flamethrower III pointless ignition. Could it be the Pertronix Ignitor III? If so, take a look at the spec from their web site and notice that it has a rev limiter inside. If you have this module inside your distributor you need to remove the distributor cap and adjust the rev limiter upwards. If you have it and it's adjusted too low, that is what's limiting your RPM. When it gets to 3500 the distributor keeps it from going any higher. Check this out before you go any further.

Here is the features of the Ignitor III:

Integrated electronic ignition - available with Solid State Ignitor or the powerful Ignitor III with built in adjustable REV limiter and multi-spark through redline.

 

Thank you so much! I never even thought it could have a rev limiter. Time to figure out how to adjust it.

 

Hah I got excited too soon. The coils flamethrower 3 but the actual ignitor unit I believe is either 1 or 2 so no adjustable rev limiter.