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.

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?

60vett

are you sure you have all the lifters out? Seems like it would probably move 1/2 inch before hitting another lobe.

wpease

I have all of the lifters out. Seems pretty strange.

wpease

Appreciate any suggestions on what might be causing the cam to not come right out. Thanks.

Vipermike

The camshaft turns one revolution for every two revolutions of the crankshaft. Turn the crank 360 degrees and the cam dot will align with the crank dot.

It sounds like maybe you have not yet removed the fuel pump.

wpease

You were exactly right on the fuel pump. Pretty dump of me to miss that, but what would I do without you guys.

wpease

I pulled the cam out and can't seem to find any information on this cam. The information written on the end of the cam is:

Y94J
Skenderian
7 08
E
270 HYD
MEGACAM
201

Any ideas what this is?

noelga

Sounds like an isky cam.
http://www.iskycams.com/

wpease

I did some looking and believe that this is a 270201 cam which is a pretty hot cam from what I had read. no wonder if won't idle.

wpease

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.

SWCDuke

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

wpease

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?

wpease

When I set the idle timing, I set it at about 10 initial (vac plugged) and then put the vac adv on the vacuum. At that point, I have about 25 or so adv.

SWCDuke

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

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.

wmf62

get a solid hub flex-fan and put all your worries about fans behind you. the noise is not objectionable.
Bill

wpease

What kind do you have?

SWCDuke

Try the NCRS Board. No other mechanically driven fan is as good as a correct themo-modulated clutch fan.

Duke

wmf62

i looked on the Jegs website and found these Flex-a-Lite:

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

JohnZ

I have that clutch (P/N 3916141) on my '67 300hp with a DeWitt's repro Harrison aluminum radiator and stock shroud, and it works fine.