Fellow recurve lovers:

Loafing at a speed shop this afternoon I fell into talking with a gang of big block Mopar racers who like slants too. I was joking about the pinging with my new head (milled .100, big valves, CC'd to yield 9.2 CR) when I first tooled around the block, before the carb messed up, still to fix it so no running since.

They said heck, plug off your vacuum advance, adjust when advance is all in with your springs since you want it all in by 2800 rpm (I do) and let er rip. I don't see why this won't work....but since on this forum many threads address the vacuum can and its adjustment, am I missing something? I realize the lovely slant has its peculiarities, like it can take a lot more cam than I ever would have thought.

rock
'64d100

From what I understand the vac advance is there to add some timing at part throttle cruise. I just curved my dist, and drove around with a vac gauge hooked to the dist line. I found from about 5~10% throttle to about 25~30% throttle I had vac at the pod. These percentage figures are just "feel of foot" but I had vac from just off idle to a bit before half throttle. It is very common for the vac pod to be disconnected on a high performance engine, especially when there is not concern about mileage.

Hope this helps.

TopHat

Rock,

That is what I did. I left the advance unplugged while tuning since I know it ads another 20 degrees on top, so I leave it till later when I am done.

For tuning I used big block springs since they limit or stop the advance very well with the 15R govenor to get 16 degrees mechanical and add another 16 degrees initial. That is my basic set up when I head for the track. Driving to work I plug in the 11R vacuum advance to get the mileage. I have my vacuum advance screwed in 3 turns so when I plug it in it does not come on or engage.

Hope that helps.

The fine tuning is really with the primary spring. At the moment I am using a medium red spring, but the super light Mr. Gasket or MOPAR spring is fun too. You just end up burning a little too much rubber with the light springs. I put in a 2.76 posi and P235 60 14's with the hope that it wouldn't spin too much. Oh' well it surprises alot of folks, especially with a single barrel 1920 Holley.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Rock,

That is what I did. I left the advance unplugged while tuning since I know it ads another 20 degrees on top, so I leave it till later when I am done.

For tuning I used big block springs since they limit or stop the advance very well with the 15R govenor to get 16 degrees mechanical and add another 16 degrees initial. That is my basic set up when I head for the track. Driving to work I plug in the 11R vacuum advance to get the mileage. I have my vacuum advance screwed in 3 turns so when I plug it in it does not come on or engage.

Hope that helps.

The fine tuning is really with the primary spring. At the moment I am using a medium red spring, but the super light Mr. Gasket or MOPAR spring is fun too. You just end up burning a little too much rubber with the light springs. I put in a 2.76 posi and P235 60 14's with the hope that it wouldn't spin too much. Oh' well it surprises alot of folks, especially with a single barrel 1920 Holley.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

This is what you do for performance and 'street draggin', it just lets you have all the init+ mech advance (I can't get any of my slants to ping with only 28-32 degrees of total advance...but then again I lose about 5 mpg doing it that way too, when I drive up to Portland or down to Eugene...)...

The vacc. advance is there to assist in getting that extra bit of advance needed during 'cruise'/highway conditions so the A/F mix is more or less properly burned (if tuned right, hopefully more, but not enough to cause ping/detonation)... If you just drive around town and don't ever make 100 mile round trips, this is an 'ok' mod...

-D.Idiot

"Wha kind a nation don't we like?!?!? Deh-toe-nation"
"Well them poor toes better watch out, then..."

I think my poor toes must be about gone by now.

Sam

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To everyone who answered...

THANK YOU!!

Darn if I can't still learn sumpin every day...even after a lifetime of asking questions. Particularly glad to get answers from folks who really know and from whom I have learned a lot.

In stead of "off with their heads" I think I am gonna try "off with the vac line!" I rarely do road trips and built this engine to enjoy, not save gas, so I will see what she will do. One of you used the magic word performance, as in what one of the speed shop guys said..."Heck man, that is a performance slant in a performance application...let it rip! I admit it is fun kickin the stuffing out of BMW's and Z cars with my 43 year old truck.

Thanks again,
rock
'64d100

Rock,

Yeah baby! That's what I am talk'n about......recurve that distributor and have some fun!

With the few minor things the good doctor suggested on my rebuild last year, they sure made a huge improvement and the car allot more fun to drive.
From a slug and ping city to wa hooo! rock and roll

Each morning, even in the dark it is a blast to drive the 60 miles to work.
It is nice to have the good mileage and the performance to boot!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG