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Yes, please follow-up once you've had the opportunity to put some miles on the changes
Well I took it out for a ride today and clearly I'm not that talented of a mechanic. Everything seemed to be fine but with the manifold vacuum I could not get the idle down under 1500 RPM. With ported Vacuum it runs at 750.
I ran it with manifold vacuum and then switched it back and it seemed to run better with the original set up. So maybe some of you could tell me what I need to do. I just don't want to reduce the idle, that seems to be too simple. If I have to go into the Distributor, then I guess Im just going to live with it. I noticed at low speeds (1st and 2nd) with manifold vacuum it ran rough as well. High speeds (4th gear) ran good. After it warmed up ran good in all gears but racing at idle.
I could use some direction.
In regards to the shroud, please, yes send me a picture. This car was restored in the 90's so not sure about the originality of the shroud. The shroud does not block any of the core. Also, remember I took my brass Harrison out and installed a Dewitt Aluminum radiator.
Well I took it out for a ride today and clearly I'm not that talented of a mechanic. Everything seemed to be fine but with the manifold vacuum I could not get the idle down under 1500 RPM. With ported Vacuum it runs at 750.
I ran it with manifold vacuum and then switched it back and it seemed to run better with the original set up. So maybe some of you could tell me what I need to do. I just don't want to reduce the idle, that seems to be too simple. If I have to go into the Distributor, then I guess I'm just going to live with it. I noticed at low speeds (1st and 2nd) with manifold vacuum it ran rough as well. High speeds (4th gear) ran good. After it warmed up ran good in all gears but racing at idle.
I could use some direction.
In regards to the shroud, please, yes send me a picture. This car was restored in the 90's so not sure about the originality of the shroud. The shroud does not block any of the core. Also, remember I took my brass Harrison out and installed a Dewitt Aluminum radiator.
Thanks
Ed
Hooking your vacuum cannister up to full manifold vacuum WILL increase the warm idle RPM . Back off the idle adjustment screw until the RPM drops down to around 750. Take it for a drive and report back.
To help you understand, the thinking in 1967 was that changing to ported vacuum would enhance the engines ability to have a clean idle. Done for smog control purposes but remember this was one of the first efforts by GM to reduce emissions and it was not done well. Swapping it back to manifold vacuum will help your engine but it also adds around 10* more timing at idle in no load situations. This is normal but you do have to reduce your idle set screw to bring the idle back down. Talk about an easy fix. Jump on this one, it will help your cooling and engine performance in general. If it does not you will want to map your timing curve, map your vacuum advance curve and see what is wrong. It can all be fixed and make you happy.
Well I took it out for a ride today and clearly I'm not that talented of a mechanic. Everything seemed to be fine but with the manifold vacuum I could not get the idle down under 1500 RPM. With ported Vacuum it runs at 750.
I ran it with manifold vacuum and then switched it back and it seemed to run better with the original set up. So maybe some of you could tell me what I need to do. I just don't want to reduce the idle, that seems to be too simple. If I have to go into the Distributor, then I guess Im just going to live with it. I noticed at low speeds (1st and 2nd) with manifold vacuum it ran rough as well. High speeds (4th gear) ran good. After it warmed up ran good in all gears but racing at idle.
I could use some direction.
In regards to the shroud, please, yes send me a picture. This car was restored in the 90's so not sure about the originality of the shroud. The shroud does not block any of the core. Also, remember I took my brass Harrison out and installed a Dewitt Aluminum radiator.
Thanks
Ed
If it ran rough on manifold vacuum I'd verify that the Vacuum canister isn't blown and adding more air to the mixture and now running lean.
EDIT: On second thought, if it was blown you wouldn't get an increase in idle speed. Disregard above!
Thanks for all the input. I will look at the seal kit and lower shroud extension.
Temp gauge is now accurate. I think. (lol) Not sure when it climbs to 230+. That will be my next check with the Temp gun. Going to let it idle after I take it for a ride and compare the gauge with the gun as it rises.
Not sure about vacuum hook up. It's set up like it came from the factory. (see picture)
Timing is set at 12 degrees BTC. Also set timing at full 3500 RPM as discussed by others on this forum.
I know when I changed my radiator I did not install a seal kit. When I took out the original Harrison radiator it did not have a seal kit that I could remember.
Where did you buy the seal kit?
Tell me what the difference is between the vacuum set up and why It would help my cooling if different then factory hook-up?
Thanks
Is it possible this fan blade is put on backwards? It looks like it would push air as opposed to pull it. Just a thought.
Actually, what you have sounds normal for a C2 big block. With a 13lb. cap and 50/50 anti-freeze/water mixture, your boiling point is above 250°. Mine will run up to over 210° , especially after a
run on the freeway . As long as it's not puking coolant, I wouldn't worry. The factory gauges aren't known for accuracy. In 65, the center mark was 180° but so many people complained that they thought there car was overheating. in 66 the center mark was changed to 210°.
I also have a 2012 SS Camaro in addition to my C3. Chevrolet did the exact thing to the oil temp gauge. Normal indicated oil temp when just cruising is around 210. ON the 10 & 11's straight up on the gauge is 200 so normal operating the needle will be over the center mark apparently leading owners to believe that their oil temp is too hot. For 2012 they made the center mark 210. So is guess it is the same deal. I'm a member of several Camaro groups on FB & at least once a week someone posts a question if their oil temp is too high on their 10 or 11 model cars. I just shake my head.
As sort of a related problem with my 435 hp, It runs fine until it gets to operating temp,150 and above it does not want to idle, it dies and dosent want to start until it cools which by no means is not near overheating.If the temp gets anywhere near 200 it will act like it only wants to start up on half the cylinders and of course not start until sitting to cool down for half hour or so. It sounds like a fuel problem or a vapor lock to me.I insulated the fuel lines. Ambient temp 70 degree day. I switched to manifold vacuum, new radiator, clutch fan. As i said it barley gets to operating temp and the problem starts, my IR gun is pretty consistent with the gauge.
Any of you guys had this problem? any advise appreciated.
As sort of a related problem with my 435 hp, It runs fine until it gets to operating temp,150 and above it does not want to idle, it dies and dosent want to start until it cools which by no means is not near overheating.If the temp gets anywhere near 200 it will act like it only wants to start up on half the cylinders and of course not start until sitting to cool down for half hour or so. It sounds like a fuel problem or a vapor lock to me.I insulated the fuel lines. Ambient temp 70 degree day. I switched to manifold vacuum, new radiator, clutch fan. As i said it barley gets to operating temp and the problem starts, my IR gun is pretty consistent with the gauge.
Any of you guys had this problem? any advise appreciated.
You might be better served starting a new thread - then your info isn't lost in the mix or diluting the original.
In regards to the shroud, please, yes send me a picture. This car was restored in the 90's so not sure about the originality of the shroud. The shroud does not block any of the core. Also, remember I took my brass Harrison out and installed a Dewitt Aluminum radiator.
Ed
Take a look at this video from @CADbrian His looks very much like mine (mine is still under it's winter wraps). Our shrouds seem to sit about 1" higher on the radiator than the pic you posted.
My fan shroud looks exactly the same. I believe I have the correct shroud for my car. Thanks for the info.
It might have been the way I took the picture.
06-07-2024, 01:52 PM
Dennis
