Where did my HP go?
 

Hey everybody,
I just put the new transmission in my car, had the heads retorqued and the valves adjusted. The engine sounds better than ever, and it's running smooth, but the horsepower and torque is gone.

I wouldn't think that having the valves and heads adjusted correctly would cause you to lose horsepower. Could the new transmission be different enough that it would have this effect? It's the exact same model transmission that I'd previously had in the car though, but this one has all of the gears and shifts smoothly.

Any ideas on what might have caused this? Is there anything I could have inadvertantly done to cause this?

Thanks,
Andrew

The only thing that I can think of is that you might have adjusted the valves too tight. This would cause them not to close and you would lose compression.
I can't see the tranny change causing a loss of power.

Ads912 has a very good point about the valves. I've seen compression drop to under 60 psi because of a valve being too tight. Also, when the heads were retorqued, was it all of them or just the bottom?

I would agree with both of you, but what's strange is that some valves had been too tight so they were loosened. I just got back from driving it and it is even worse than I thought. The car's top speed is about 65mph, nothing I could do could get it above 65 (well I didn't try going too near to the redline in lower gears, but that didn't seem like a good idea), and it barely made it over some bridges it's crossed dozens of times with no problems. It won't accelerate at all in 5th, and barely does in 4th. It seems to accelerate fairly well in 2nd and 3rd (not 1st) but then drops off when it hits 3500 which was when it used to start flying.

The heads were retorqued professionally by my local porsche shop who have worked on the engine several times. I honestly didn't ask which ones had been retorqued, but they're very good and very thorough, so I don't think the problem started there.
I don't know... I guess I'll call them on monday though. Still, if anyone has any suggestions or ideas I'd really appreciate them.

How are the carb linkages, and the throttle bushings, and links. Also, how is the timing?

lol, ever noticed it's much easier to find out what's wrong with your car in the daylight? Josh, you were right, it was the linkage. I'd never changed throttle linkage when I bought the car. It has 44 webers, but they've always opened about 75%-80% of the way and I never really wanted any more. After putting the engine back in though. They're only opening maybe 50% of the way at best. I really wish I'd switched linkage with it out of the car, but has anyone done this with the engine in the car? Any advice on what linkage I should switch to in order to get them to open up fully?

Unless you have the incorect parts you should not need to swich things just ajust things corectly so the butterflies open all the way.

true, but it was a complete pain in the butt adjusting them the first time, and I don't quite remember exactly what I did. Plus it'd be nice to have them open up all the way, and I can't do that with the solex linkage. I'd rather switch to new linkage and not have to worry about this again.

Also check the accelerator link at the firewall, as well as the busjings at the tranny. Mine are shot and I am having to replace them. If they are shot, they will provide so much slop that you will only have half throttle, if that.

Thanks guys, I'm glad that this turned out to be something relatively simple. I was really worried for a bit. I'm looking around for good linkage kits, and I'll check out the firewall link and bushings.

Andrew

Hi Andrew

You should be able to adjust the linkage so you obtain full throttle without buying any new parts. Do check the bushes on the trans. If there is play in the ball sockets you could cut out a small piece of plastic, I used the top of a plastic bottle as it also has a slight curve on it. Cut it out just s a little smaller then the ball socket hole and put it in with some grease. This will take up the slack and tighten up the linkage. Make sure it still allows each one to rotate freely. A cheap easy fix.

PS there is also some plastic guides in the central tunnel which the accelerator rod sits in. If you?re replacing everything else you may think about changing these.

HTH

Alan.UK

I'm 99.99% positive that there is no way to adjust the linkage that I have and get them to open all the way. Harry Pellow (The Maestro), my local mechanics, and my own findings have confirmed this. The problem seems to be the bell crank on the rear of the fan housing. No matter how many adjustments you make, the bell crank can only move so far. Which in my case is about 75% open on the carbs.

I would assume that new linkage would either replace or overcome this problem. Does anyone have any experience doing so? I'd like to find out if I can just replace linkage, or do I need to find an alternative bell crank as well?

If anyone has replaced their linkage to get webers to open all the way, I'd appreciate any advice you can give.

I am running webber 40s with the stock linkage and my carbs open 100%. I guess I didn't know it couldn't be done so I just done it anyway. ;)

What is the problem? Are the carb arms too long? is something in the way? Do 44s have difrent arms? 90 deg of motion is the same regardless of the carb used. One thing that will make a difrence is the carb arm length.
If you shorten the distance between the linkage ball on the carb arm and the butterfly pivot point you will need less motion to open the carbs all the way up. This is an easy thing to do. If the balls are bolt on just drill new holes and bolt them up. Some times they are cheap press in and you need to carefully buzz off the backs and then pull the balls out. Drill new holes that press fit the ball tightly and peen or MIG tack the back to hold em' in place. You can get difrent length and angle arms for Webber carbs too

Green,
Thank you! I hadn't even thought about touching the carburetors (honestly I didn't even know you could switch arms). I'd just been trying to adjust the linkage.

I still may try to adjust the linkage back to where it was just because I'd like more pedal travel, but the carb arms! yes! The ones I have on now are a little over 5cm long, and they do rotate 90 degrees. So the linkage has to move about 8cm total. Shortening the length of the arm will definitely help out. Maybe they'll finally open 100%.

Do you know where to find different length carburetor arms? Mine bolt on to the carb body with everything else, and the ball and arm are one piece. I'm not the greatest person in the world when it comes to machining things, so if I can find a replacement I'd like to try that first.

Hi again
I was also running 40 idfs and I had 100% opening. I'll have look to see if I can find any pics.

Alan.UK