63 327 Overheating problem
Thread Starter
Intermediate
Joined: Jul 2006
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I have pulled the engine apart to install the new cam. Interesting that when I took the timing cover off I saw that the alignment dots were not aligned. The cam sprocket was 180 degrees off of the crank sprocket dot. I am not sure exactly what difference that will make, but certainly does not look right.
I am not able to slip the cam out. It comes out about 1/2 inch and won't come any further. It won't go back in either. Any suggestions?
I am not able to slip the cam out. It comes out about 1/2 inch and won't come any further. It won't go back in either. Any suggestions?
Burning Brakes
Joined: Jul 2004
Posts: 825
Likes: 17
From: Rowlett, TX
Originally Posted by wpease
I have pulled the engine apart to install the new cam. Interesting that when I took the timing cover off I saw that the alignment dots were not aligned. The cam sprocket was 180 degrees off of the crank sprocket dot. I am not sure exactly what difference that will make, but certainly does not look right.
Originally Posted by wpease
I am not able to slip the cam out. It comes out about 1/2 inch and won't come any further. It won't go back in either. Any suggestions?
Racer
Joined: May 1999
Posts: 470
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From: Marietta, GA
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Thread Starter
Intermediate
Joined: Jul 2006
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I had some issues installing the new GM cam which were addressed in another thread I created to discuss a starting problem, but now have the cam installed and the car running. It runs great and idles very well now. I drove it around for about 10 mins and seems to have a histation when first accelerating, but then kicks in nicely. Not sure what that issue is. After about 10 mins, it went back to overheating. I have the timing set with about 36 total timing, 10 initial.
Race Director
Joined: May 2000
Posts: 12,712
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Put the B22 VAC back in. This is not the source of the hot running, but the B28 is too aggressive for the base engine cam.
IIRC you said you have a "new" fan clutch. It's been discussed before that replacement clutches (GM? other sources? not sure which) are set up for later cars with 195 deg. thermostats, and the clutch doesn't engage until a higher radiator exit air temperature.
There is someone who rebuilds the original fan clutches (don't recall the name or web site), and apparently they engage at the original radiator air exit temperature for models originally equiped with 180 deg. thermostats.
Set the idle mixture screws at 1.5 turns out from the seat. Then set the idle in Drive (set the parking brake firmly and thoroughly chock the wheels so the car doesn't run away from you) at about 450-500, then adjust the idle mixture screws to get the highest speed/vacuum.
AFAIK the original 3460S PG carb communicates full manifold vacuum to the VAC, so the total idle timing should be initial plus full vacuum advance, but I have never personally verified the above. Perhaps you can.
Duke
IIRC you said you have a "new" fan clutch. It's been discussed before that replacement clutches (GM? other sources? not sure which) are set up for later cars with 195 deg. thermostats, and the clutch doesn't engage until a higher radiator exit air temperature.
There is someone who rebuilds the original fan clutches (don't recall the name or web site), and apparently they engage at the original radiator air exit temperature for models originally equiped with 180 deg. thermostats.
Set the idle mixture screws at 1.5 turns out from the seat. Then set the idle in Drive (set the parking brake firmly and thoroughly chock the wheels so the car doesn't run away from you) at about 450-500, then adjust the idle mixture screws to get the highest speed/vacuum.
AFAIK the original 3460S PG carb communicates full manifold vacuum to the VAC, so the total idle timing should be initial plus full vacuum advance, but I have never personally verified the above. Perhaps you can.
Duke
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Knowing that the new cam would resolve the low vacuum issues, I put the B22 back in when I put the cam in. That seems to fully engage at idle now with the 17" of vacuum at idle I have now.
You could see the temp go to about 185 and then drop when the thermostat opened. Crept up to about 190 for awhile and then started to creep up over 200.
I have heard about the rebuilt fan clutches. I will do some checking on the web and see what I can find. I have a new replacement GM fan clutch for this engine. GM ordered it for me. I am sure it is a 195 clutch. Will that make that big a difference?
You could see the temp go to about 185 and then drop when the thermostat opened. Crept up to about 190 for awhile and then started to creep up over 200.
I have heard about the rebuilt fan clutches. I will do some checking on the web and see what I can find. I have a new replacement GM fan clutch for this engine. GM ordered it for me. I am sure it is a 195 clutch. Will that make that big a difference?
Race Director
Joined: May 2000
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That's correct total idle timing.
Find out at what temperature the fan clutch tightens. This can be tested by revving the engine periodically to about 3500 as the temp rises at idle. Once it engages you will feel more air flow and hear more fan noise.
Figure that the fan clutches for the later engine with 195 stats don't tighten until 15-20 degrees beyond where the older models fans designed for 180 stats tightened. At idle or low speed driving, that's going to show up on the temp gage.
At highway speed it will run close to stat opening temp.
Duke
Find out at what temperature the fan clutch tightens. This can be tested by revving the engine periodically to about 3500 as the temp rises at idle. Once it engages you will feel more air flow and hear more fan noise.
Figure that the fan clutches for the later engine with 195 stats don't tighten until 15-20 degrees beyond where the older models fans designed for 180 stats tightened. At idle or low speed driving, that's going to show up on the temp gage.
At highway speed it will run close to stat opening temp.
Duke
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Joined: Jul 2006
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In looking around on the net, I can't seem to find anything yet that references an original design. I will keep looking. What do you think about the torque based clutches. Seems like that would resolve the low speed issue. Just might be louder.
Race Director
Joined: May 2000
Posts: 12,712
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Originally Posted by wpease
In looking around on the net, I can't seem to find anything yet that references an original design. I will keep looking. What do you think about the torque based clutches. Seems like that would resolve the low speed issue. Just might be louder.
Duke
Race Director
Joined: Jun 2006
Posts: 17,901
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From: Inverness FL
St. Jude Donor '07
Originally Posted by wpease
What kind do you have?
400-1817 17 inch asymetrical 7 blade (probably a little quieter) not fond of the blue hub though
400-1617P 17 inch 6 blade, steel blade
400-1717P 17 inch 6 blade, aluminum blade (lighter weight)
400-14538 spacer (verify the application is correct for replacing a thermal clutch)
i liked their selection better than Summit's
Bill
Last edited by wmf62; Aug 7, 2006 at 07:10 PM.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
Originally Posted by wpease
I have a new replacement GM fan clutch for this engine. GM ordered it for me. I am sure it is a 195 clutch. Will that make that big a difference?
