so a 264/264 @108 cam is not so good on stock engine.....

westu37

New member
WSA111, you were absolutely right. the clay smith cam 264/264 @108 is too agressive for stock. Is functions but has no vacuum at idle in gear. (less than 5 in/hg)

With that said, the cam is ok after 1000 rpm and feels good at cruising speeds.

SO, I want to confirm before ordering another cam, that 264/264@110 will give a smoother idle, more than 10in/hg at idle (in gear).
If there is other suggestions I am all ears.

The current set up is stock rebuild on engine /head/valves/rockers etc..., holley/motorcraft 1940 with spacer(215cfm?) stock 69+ exhaus manifold and 2" pipe to under car, then 1.75" midpipe to tailpipe, stock dizzy (68+) with dual advance/electronic ignition, stock c4 trans/converter and finally, trying to use a brake booster with drum brakes.

I am driving this May 13th to 27th to MO and Nashville, for the car show. I want to try to get this done before May 6th to have time to drive it before the trip.

Wes
 
unless you are going to build on what you already have in the future, i would suggest the 112 lobe separation angle instead of the 110. the idle will be smoother even than the 110, and it will pump up the low end power as well. this assume that your compression ratio is around 9.5:1 or less though. at 9.5:1 you are in a grey zone where you might get too much low speed cylinder pressure and might run into detonation problems, so think carefuly before going with the 112 and having compression higher than 9.5:1.
 
Since its a stock engine, i would go with a Schneider 256 degree cam. Give Jerry a call & he will advise you further. A 110 L/C with that 256 cam will be fine.
 
FWIW, I'm running the 264/274 110* Clay Smith cam. I have 15" of vacuum. I have a stock converter and it's a little boggy from a standstill but really wants to jet once the RPMs start to climb. I'm running something like a 2.7 or 2.8 rear-end. I'm going to have the converter modified in the near future.
 
I'm likely to do the header back exhaust at 2", with a possible dual exit, but most likely single exit. I may put the 2bbl webber 36/36 but the engine is running well otherwise with the 1940 now, so a cam choice for only stock engine and exhaust mods is most likely. ( it is the wifes car after all, so the more tame the better)

Wes
 
westu37":h7duz6ls said:
cam choice for only stock engine and exhaust mods is most likely. ( it is the wifes car after all, so the more tame the better)

Wes

Yeah, 256H or you might even want to consider a 248-56H, better than stock, will keep compression up and power curve down where most people need it.
 
Jeesh, U guys R really dialin it in,
great thread!
 
thanks for all the input guys. I also found out that the chart in the CI archive is where I got screwed up. On the chart for the Clay Smith comparisons, it showed idle, vacuum and other specs the same as the 110 degree, so I thought why not a little lopey idle. I should have used a little more common sense. :banghead:

So, I'm split between the Clay Smith 264/264 @110 or the shnieder 256/256 @110 or the CS 264/264@112.......
It will be driven an average of hiway and country roads, with some city. I NEED VACUUM more than anything else; I have a brake booster, vac. modulator, vac. advance on dist. etc.

IS THE 112 going to supply MORE vacuum than the 110 cams or about the same? That is the most important answer I'm looking for.

Thanks.

Wes
 
My understanding is that the 112 will provide more vacuum at idle. I've got a Schneider 248/256H in my motor right now, but I couldn't tell you how happy I am with it because I haven't finished getting it all back together yet, but I called Jerry @ Schneider and told him I was using a brake booster and was doing a mild build and that was what he recommended.
 
Do not even consider the Clay Smith Cam @ 110 L/C. A 112 is borderline in your case. Go with the Schneider 256 @ 110.
 
What is the initial timing?
I see where it was suggested to set it at least 16 degrees but did it actually get done?

The intake lobe center is specified at 104 ATDC for cam installation timing.
Was the cam degreed close to that?
 
Initial advance is dependent on your combination. It could result in too much total advance.
Need more information on your combination.
Static compression ratio, cranking compression, zero decked?????
You stated you purchased a dual point distributor, but what is the advance curve. Too much mystery here to even give you a correct answer.
You should have purchased the DS11 and gone from there. But your budget might have swayed your optimum combination. As stated before keep in touch we are here to help.
 
Thank you all for the input!

The initial advance was dialed in to 18* btdc. the idle would like closer to 20 but total advance was already at aprox 36-38* (hard to see timing mark on crank pulley)

I just pulled the motor out last night for a couple of issues. I have a rear oil leak that I suspect i the rear main. The flex plate bolts were threadlocked, I replaced the oil pan gasket twice and can't see if the rear half circle seal in the back is the leak or the rear main, and because I'm driving this to the car how in Nashville, I need no leaks.

Matt at vintage is shipping out the 264/264@110 and should get it today. I should have the engine ready for the swap tonight.

Bill, I know you suggest the 256 @112 (shnieder?) but with Matt helping me out, I'm committed. At this point the 264/264@108 did drive well, felt good on power, just had no vacuum for power brake and vac modulator for trans. I'm ok with the 110 as long as I can get at least 14 in/hg.

BTW, I did degree the cam before and had advanced it aprox 3.5-4* according to my math on the degree wheel ( I got the adjustable dual chain timing set to help dial the timing in)

I'll keep you all posted. Wish me luck.


Wes
 
UPDATE:

I have the seals, gaskets and cam in. I dialed it in at 109* instead of the recommended 4* advanced. It fired right up, I have improved vacuum, but not the best. I also notice that the vac gauge flutters. Is that normal? I am getting 10-14 in-hg now.

It also seems that as the engine warms up, the idle kicks to 1500-1800 rpm. If I pull the pedal back it is better, but not down to 1000 or less.

Can I use a stiffer/stronger return spring?

Is there an adjustable rod for connecting the pedal linkage on the firewall to the bell crank below the carb?

Other than that, everything seems ok so far.

Wes
 
westu37":pccfphcd said:
UPDATE:

I have the seals, gaskets and cam in. I dialed it in at 109* instead of the recommended 4* advanced. It fired right up, I have improved vacuum, but not the best. I also notice that the vac gauge flutters. Is that normal? I am getting 10-14 in-hg now.

It also seems that as the engine warms up, the idle kicks to 1500-1800 rpm. If I pull the pedal back it is better, but not down to 1000 or less.

Can I use a stiffer/stronger return spring?

Is there an adjustable rod for connecting the pedal linkage on the firewall to the bell crank below the carb?

Other than that, everything seems ok so far.

Wes

ok wes, before you start installing heavier return springs, get the carb adjusted, AFTER cam break in.remember that you have change a lot of things, and your old settings are no longer any good. there is an idle speed adjustment on the carb, as well as an idle mixture adjustment. you also need to reset the ignition timing as well.
 
I have initial timing reset to about 15*

Idle at cold start set at aprox 1000 rpm.

Mixture screw about 3 turns out.

(Holly/motorcraft 1940 carb-unknown jet size-probably stock size for holly/motorcraft)

Wes
 
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