'71 455 Electra - Not enought power?

'71 455 Electra - Not enough power?

Hi everyone, I have the '71 electra you see in my avatar pic. This is my first big block Buick, so forgive me if my expectations for output is a little high.

I just feel like the car should have way more power than it does. I mean, in the past I had a smogged '74 2bbl 350 Century that was a lot quicker. With the Electra, I can barely turn a tire off the line and it's an open rear end.

I don't know if I'm not factoring weight in the equation or what, but it feels like it should have more, well, balls in plain english.

I've already updated the points ignition with an electronic conversion kit and a hotter coil from MSD, but I never touched the carb yet or the single 2 1/4" exhaust.

Could this be where my trouble lies - in the carb or restrictive exhaust system, or am I expecting too much? I was hoping some other full size owners will coment and let me know.

 

I would not think that those mods will increase performance if the factory set up was within spec.


Recurving the distributor and making sure the total timing is set up to 32 -34 degrees would be a cheap improvement. However it is a very heavy car that likely only ran in the 16 second 1/4 mile range from the factory.

 

I have a 73 hardtop sedan and can tell you that the weight is a major factor. You're looking at somewhere in the neighborhood of 6,000 pounds (depending on options). Trying to compare it to a 3,500 pound A-body just isn't reasonable. Based on the idea that 100 pounds equals 1/10th at the track you can figure that the exact same engine will run 2 to 2.5 seconds slower in the C-body than in the A-body.

You want an eye opener on weight than drop the 350-2 from the Century into the Electra and watch how slow it'll go.

On the plus side, you can do all the performance upgrades that the GS guys do to really make the car into a quick cruiser. Just remember you'll still be a bit slower than they are when you're done.

 

Open up your exhaust.(headers/duels) get an after market alumn manifold and then have the carb gone through and freshened up a bit. theres several members on the board that do a great job. You'll feel a difference. If you want more start lightening up the car. Every pound helps.

 

Your car weighs arond 5000lbs (close to my Riviera) you should be able to roast the right rear. Are your secondaries opening? also as mentioned recurve the distributor and dual exhaust. My guess is with 30,0000 miles the secondaries are slugged closed.

 

Not sure what the stock timing specs are on a '71 but I can say that the '70 stock timing specs are very conservative and generally aimed at minimizing NOx emissions. You're further handicapped because you lost at least one point of compression. From a power making perspective you might easily leave 20 to 40 horsepower behind simply by following the factory tune up specs. As an example an SF '70 455 initial timing spec is 6 degrees advance. Try that and you'll swear you're towing a boat with a flat tire and the parking brake engaged. Install a simple recurve kit in the distributor and increase your initial advance and you'll be most surprised. You'll want to read Larry's timing thread for the details.

 

My riv was the same when I first started driving it. Slow as hell. Fully rebuilt the thing and had the heads and manifolds attacked heavily by the die grinder. Combine that with the 750cfm Holley street HP, Pertronix flame thrower III ignition set, a big exhaust and a High stall torque converter.

Well it goes apesh*t now. Will spin the wheels at anything over half throttle.

Have taken off so hard once the exhaust hit the ground!

In saying that the new pertronix kit you installed should help no end. Get that timing dialed in perfectly and the performance gains are very noticeable.

 

Thanks for the input guys. Maybe it's becasue I'm a younger guy, but what the hell is a recurve kit?

I did time the car at an idle (8* advanced) when I installed the electronic conversion kit, but I have never power timed a car before. I'm assuming that involves timing it at 1/2 or WOT(?) Can someone explain?

I have a chrome open element air cleaner on the car now and I can hear the secondaries open when I put my foot down, but if they are opening all the way or at the right time is beyond me.

I did find some interesting issues with it today. Before I left work, I borrowed a hand operated vacuum pump from a tech and pulled a vacuum on the vacuum advance with the distributor cap off. It did nothing. I can hear a leaking noise from the diaphragm, so I'm pretty sure the innards are shot. No biggie - ordered a new one.

I found that the 3 port vacuum switch has gone bad as well; it's the one that sits in the coolant path on the driver's side of the intake. I let the car warm up and checked all 3 ports for vacuum and found out that only the bottom port is getting any. The top two get almost nothing. Pretty sure it siezed 1/2 way open. $8 part - ordered it.

I've already replaced the plugs, wires, cap and rotor last month. Dual exhaust and a carb rebuild are FOR SURE on the list - probably not until the spring though.

I understand this is not a race car, and it will probably never see a drag strip. I just feel that the 455 is hiding something from me.

 

http://www.v8buick.com/showthread.php?t=28438

Best info on the subject here.

http://www.v8buick.com/showthread.php?t=63475

 

That 2nd link made my head hurt. I understand it to a point, but it seems like a mindf***. I'd rather leave that to a pro. I'm just not that confident in myself to tackle an issue I have limited knowledge about.

Now that I see how the recurve kit for the centrifugal advance works, I will try and find a kit (the posted part # in the 1st link to Jegs was dead). I think I will also leave that for someone who knows what they are doing.

 

Basically just get a dialback timing light, cap off the vac advance, set timing to 32 or so with the mechanical advance all the way in (high rpms). The base timing at that point will be whatever it happens to be.

Then get a vac advance canister that's only 10 degrees, or modify one to limit it at that much advance. This will help prevent detonation when letting off the gas after a wide open run.

The recurve kits are what you use to adjust how much mechanical advance you have and when it all comes in.

My car has 28 degrees of mechanical which means I should be running at 4 initial, but I'm actually running it around 8 initial since I have slightly lower compression than you guys with the 70-71 motors. I'm using the middle weight springs from a recurve kit to get all the timing in by the upper end of my usual driving rpms. I have a 10 degree vacuum can to avoid the headaches of an adjustable or modified unit. I can run the cheap gas with no detonation, but you would have to run better gas or lower initial if you had the same amount of mechanical advance as I have. The performance from the timing adjustment alone is enough to get the car to lean back on heavy acceleration.

On a side note, where are you guys coming up with 5k pounds for an Electra? It's bigger and heavier than a Riv is for sure. The registry lists it at 5,500 which is their highest value allowed for a passenger car, and the guy I bought mine form had it weighed and it was just a hair under 6k pounds. The flatbed driver that towed it for me actually had his truck lean back and said it was the heaviest car he's ever had on the flatbed, and he's towed Hummers and Expeditions.

 

'71 Electra's a little lighter than 73-74-75-76, mainly because of the huge bumpers of those years.

 

TCS Switch? Transmission Controlled Spark
If I recall, that prevents vacuum advance until the engine is warmed up and allows vacuum advance only in 3rd gear until then.
:idea2:
Been a while since I had to think about that one. Back in the day we usually just eliminated that thing and ran the vacuum advance directly to the carb.

Dual exhaust will help that boat too.
My '72 Electra I added duals to, and power timed it till it was just right. It was no slouch for such a heavy car.
Not Gran Sport fast, but it would put you back in the seat some.
:3gears:

 

Thanks for clearing things up guys. My dad has a real nice digital dial back timing light I can use. I'll have to try power timing it myself before I give up and bring it to someone. Now, where can I find the right recurve kit? How can I figure out which springs and weights are right for my application?

 

Makes sense. I keep forgetting about them crash bumpers they added. I do know they got slightly bigger every year so it makes sense that the car got heavier. Makes me wonder what a fully loaded '76 hardtop sedan weighs in at uzzled:

 

I'm pretty sure he means the TVS (Thermal Vac Switch). That allows ported vac to the advance until the car gets too hot. If the car starts to run warm it switches to manifold vac to advance the timing and up the rpms, which should in turn cool the car down a little.

I just ran straight manifold vac from the carb and left my tvs sitting empty in the intake. I'm not sure if it worked right or not, but I figured it was just another thing that could go wrong so I skipped it.

 

That's it.
Like I said, been some time since I even thought about those things.

 

That's right, it's a thremal vaccum port.