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Discussion Starter #1 (Edited)
Power in a strain with my 57’s 235 6 is poor. Such as going up a hill, or past 55 it’s a real dog. My old 59 Chevy had a 235 in it and seem to have no problem with hills or going over 55. The heat riser valve is stuck for sure in my 57 and won’t move. The flat on the weight of the heat riser is parallel to the ground. Is it open or is it shut? I know if it is shut this could be my problem. If it’s open, I’ll look else where for the problem.
Thanks to all for your input. I did a search and could not find a for sure answer to what is shut or open. Also, please don’t tell me to put a V8 in it, I’m keeping it original (Snagged another trophy with it Saturday, judges like those Blue Flame engines, their different).
 

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I may be wrong, but once its warmed up, it shouldn't matter if thats open or closed ? I just checked mine and its still hot from driving earlier, it is parallel to the ground, I can push up on it (towards the engine and it moves) but I have never seen it anything other than parallel to the ground. It sounds like more of a carb issue. I put on a 2 barrell and haven't looked back, but mine isn't 100% stock either. Sorry I couldn't help more.

FYI, I have an electric choke, but its not hooked up, so only heat the carb gets is from the manifold and it still warms up and runs good pretty quickly.
 

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Discussion Starter #3
Thanks for the quick reply. If yours does good with it in the same position as mine it must be something else. The engine was rebuilt around 12 years ago, idled a few times then sat with out running for the rest of the 12 years. All new valves and pistons were installed because the cam gears stripped and the valves hit the pistons and bent them and cracked a few pistons, so all new ones were installed with the rest of the rebuild. I took out the plugs, and put oil in the cyclinders and let it sit for a few days, then turned it over by hand with the plugs out and everything seemed fine. I also rebuilt the carb. It starts up fine (I had put a manual choke on it) and does not smoke at all, so I think the rings are Ok. It just don't have as much power as I'm sure it should. I have been driving it for 10 months now to local shows and it doesn't over heat and runs smooth on flat ground, but put it in a strain and it's a dog. New points, condencer, rotor, rotor cap, coil and wires. Also new fuel tank pickup and fuel pump. It's getting plenty of gas to the carb. Timing is on the money. I"ll do a compression check tomorrow to see how that is, but I feel it will be OK. I even jacked it off the ground to see if any of the wheels were dragging and all 4 were fine.
Thanks again for your reply. I'll take any helpful hints. Also, I am not new to engine and automatic tran rebuilds. I'm 61 years old and use to work rebuilding engines and trans of all brands and have done a lot of them. Maybe I'm forgetting something in my old age!
 

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Well then, you are probably alot more informed than I am on these things. I don't have much experience with engines, especially with 235, just what I have learned with mine. My single carb was seeping fuel out of it, that's why I knew it was my carb. Good luck to you. Hope you get it worked out.
 

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I do not think my speculating on what else may be causing your poor performance would be of help so I will try to answer your question on the heat riser. It is currently stuck on, the way you describe it and that is bad. My ’55 was like that when I got it and it performed just awful. Oh, the old girl started right up and never faltered except for the occasional backfire due to one weak valve spring; but the Stovebolts were like that. They had such a wide range of tolerances that they ran when a less-forgiving engine would not. That was part of their reputation and long-term success. But she did not have any “guts”. I was determined to free up the riser. It took a few days. First came the penetrating oil. My oil of choice was “deep creep” by Seafoam and I applied it after the engine had run for a while. I assumed that the heat would pull the oil into the mechanism. I then found that getting a grip (purchase) on the counter balance was difficult and I could not budge it with my hands. After many different tools and approaches I found that needle-nosed vice grips could allow me to apply some leverage. I was applying so much force that I was afraid that I might break it off but an old restorer said: “so what: you cannot make it worse”. After more penetrating oil, I got a small movement on the second day of trying. After that it was “move, oil, move some more, oil, move a lot more”. Finally it was free as a bird so to speak. The bi-metal spring was long gone but I found one of those as well and after all that she did perform much better.
I hope that helps.
 

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The heat riser weight is normally horizontal and with the heat from the exhaust manifold it spins it vertically upwards :D
 

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Discussion Starter #8 (Edited)
Ok folks, thanks for all your help. It means a lot to me. I think I got the problem fixed. I got to work on the 57 today, so I started at square one. I pulled the plugs and they looked like everything was fine and in perfect tune, I then did a compression check. Number one was right at 130 psi and the rest were between 150 to 160. I figure it setting up for 12 years that maybe one of the valves on number one was open and the seat started to rust and wasn't seating as well as the others. None of the cyclinders were pumping oil, so I felt the compression was ok as my 59 Motors Manual said 130 psi compression was minimum for this engines year. Well, then I took off the valve cover and readjusted the valves, but they were fine. I then reset the distributer to 0 degrees and also set the points. I figures I'd tackle the heat riser next. But just before that I rememberd that I never got to check the carb for full open as I'm always by my self and it's hard to be in two places at once. I didn't want to leave any stone unturned so I phoned my son and had him come over to help as it was his day off work (I'm retired so I can arange to be off when I want). I had him push the gas pedal to the floor and guess what, the butterfly in the carb only opened about one quarter the way! That made me happy. I knew all the linkage on the side had never been changed during the rebuild, but the kick down to the trans had which moves the bellcrank on the side of the engine and changes the rest of the linkage had been off during the trans rebuild. I readjust the kick down leaver and the carb butterfly opened almost all the way then. Long story, but I took it for a test drive and thought I had a new engine in the car, plus I went up the hill that it would barely go up before and it climbed it like a champ. So now I feel stupid that I didn't check this before, but I never had anyone around when I would think about it and I did think about checking it lots of times and never got around to it. No wonder the car would only do 55 at full throttle before which was really quarter throttle. Thanks again for all your help,
Signed, Stupid!
 

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Thanks for letting us know, not stupid at all. Glad you got it worked out !
Definitely not stupid – since you figured it out methodically. (And managed some 'quality' time with your son!)

The stupid thing would have been to not post on this forum. :)
 
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