have 289, need help

[Stude Ranch]

OK. I will concede advancing of the cam timing of a 70's engine
might only be bringing it back to where it should have been. (read my last comment). But by the service manual, I am now in the area of 5 degrees advanced instead of the 10 or so retarded that it was when I bought it. Which is closer? It seems to start and idle better than it did, but high speed seems about the same. (if you call 3600 high speed). this would be the opposite of your guess of high speed being better, and loosing on low. I agree theat usually if you gain in one area, you will loose in another.
I am still wondering if there are any HP-torque curves vs. RPM. Maybe no one has one, but what RPM is the best torque, and what is the best for HP ?
On the compression, if you reduce 140# ( book says 140-160) by 12% it is 123 shich isn't that far off what I have. Some where it sticks in my mind that power was reduced by 3 % per 1000 elevation which would be 25# less than 140, exactly what I have, unless the compression is guaged from whatever elevation South Bend is from.
Most the engines on this place are probably down a bit on compression, but they run well for what they are.
That said, I am sure the compression is not all that great as it is a long way from new, and I have no idea of its past. I think that the advice about timing or carburation has more validity. When it comes back from the trans shop I will work on the advance curves and maybe swap distributors. Anyone know if a Delco distrubutor for a studebaker can be upgraded to HEI? I can also swap in a couple of different carbs and see if that helps. I don't see any reason doing an expensive overhaul if I don't have the confidence that I will be happy when it is done.
I once had a riding lawnmower with a worn out engine, about 70# compression. I bought a new long block from Briggs and Stratton for about $600 . It started better with better compression, but power was still the _________(and thats bad). That lesson still stings.
thanks for the help David

[Milaca]

I have a 1982 El Camino that ran smooth with a 305 but had little power. I tried a few things and then gave up and brought it to a mechanic. Turns out that two plug wires were swapped with each other making the 8 cylinder only run on 6 cylinders. Just a thought, but you may want to confirm that the plugs are indeed wired to the correct corresponding outputs of the distributor cap.
The other possiblity may be that your fuel pressure is too low to supply enough fuel to run any faster. Junk in the fuel line? A pinched fuel line? A bad fuel pump? A hole in the rubber line thus sucking air? A collapsed rubber fuel line? Good luck.


Brent's rootbeer racer.
MN iron ore...it does your body good.

[sals54]

StudeRanch, Ditto with what Milaca said, but do remember that the Stude Distributor turns counter-clockwise, when setting the wires to the correct plugs.

sals54

[buddymander]

According to your numbers, you have less than 10% variation between cylinders. The actual numbers are of less importance. I always degree the cam based on what my compression gauge tells me. That way I will have the most low end power. Set that cam to the highest compression reading and your engine will run smooth and sound great. It will also be much more responsive. This doesn't work with long duration cams, or cams with a lot of overlap.

[Stude Ranch]

Dear Buddymander, You have me stumped on that on --how to degree the cam based on compression. Maybe you could explain yourself.
Two other symptems I have now remembered.
1) the motor turns over hard. It is very difficult to turn by hand. My sons Champ with 259 turns much easier. We havn't done a compression test yet, but it runs quite well, may burn a little oil, but if you push on the v-belt to get a little traction, it turns fairly easy. Could it be possible something is binding, which could suck up power,and cause heating?
2) I have pulled the plugs a couple times to get hints as to what is going on, and the right side of the engine is running richer than the left. It confuses me as I would think that if one side of the carb was putting out more fuel, 2 of the plugs on each side would be darker. Any ideas on that?
Thanks David

[JeffDeWitt]

What about an exhaust system partly clogged on the right side? That could account for the plugs and at least some of your other problems.

Have you checked the vacuum?


Jeff DeWitt

http://carolinastudes.net

[Milaca]

Is your manifold heater valve opening up when the engine is warm? The cast iron weight is supposed to open the valve when the spring becomes warm. These tend to rust and not open if not taken care of.


Brent's rootbeer racer.
MN iron ore...it does your body good.

[sals54]

I remove all the manifold heater valves from my exhaust systems. I think they're antiquated and too problematic to rely on. You could fry an engine in the time it took you to troubleshoot the problem. Can you tell that I can't stand them?

sals54

[JeffDeWitt]

It still could have a partly clogged exhaust, maybe a baffle broken loose in a muffler or even something like a mouse nest.

Does it have duals? Does it seem like the same amount of exhaust is coming out of both sides?

Jeff DeWitt

http://carolinastudes.net

[Stude Ranch]

new stainless exhaust from Silvertone 2 inch duals, and mufflers from there also.
I welded in a crossover pipe just behind the transmission mount.
as he didn;t have one available. New Manifold heater valve from SI. R3 cast headers From SI.
I too thought that a restriction might be the culprit as the pipes were rusty and dinged up I have to admit I didn't try it without the mufflers. I noticed no difference other than a lot less noise from leaky header pipes.
Maybe the manifold heater has someting to so with one side burning richer than the other, I think it was the right side that showed richer.
Any one have any ideas on the engine turning over dificult by hand(12/8 post) ? Thanks for everyones input. David

[buddymander]

You first check the compression, then change the cam timing either advance or retard, maybe half a tooth. Check the compression again. If it's higher, go in that same direction another half or less and check it again. Keep going in whatever direction raises it until it begins to drop off. If you have two readings the same, then the point between them is probably the highest. If the manifold heat riser is stuck, then that side has to force the exhaust up under the carb, and that restrictive exhaust would darken the four plugs on that side; plus restrict your rpm.