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Author Topic:   Cam Question
Winland Racing
Member
posted December 22, 2003 11:32 AM
I got a 350 with aftermarket pistons bored .030 over. I run 194 heads on a 041 casting, stock 4 barrel mainfold, quadrajet, stock manifolds and single 2" exaust (enduro stock rules)Powerglide with 342 gears (610 total)
I am thinking of buying a cam from speedway # 915110691
Hydraulic-Our best selling hyd racing cam Excellent mis range and top end power.
Rpm range 3250-6750,deg dur@.050 int 238 ex 244, deg adv int 298 ex 300, 106 deg, gross lift int 502 exh 516.
Does this look like a good cam to pull a car off the corners. I need to run 17vac at 1500 rpm. 200 lap enduro races
Any advise or feedback is appreciated.
WR
#66


waltonjr1
Member
posted December 22, 2003 01:57 PM
With a 610 final, unless your running a 1/2 mile track you should not turn close to 6750.Even on half mile its doubtful unless your running really small tires. Try a comp cam #12-242-2, this is a great all around cam.It pulls hard till around 6200.Its suppose to be good only to 5750 but i push it a little further.Should pull 17 at 1,000.Im using this cam with 461 heads.

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DEANJR#22


rico 08
Member
posted December 22, 2003 04:10 PM
That 106 lc will kill the vacuum,you could try bleed down lifters but i think you will need to widen the lc out to at least 110 to get anywhere close to 17 inches.You may luck out and have that cam do it but i doubt it.With that engine i'd get a cam ground special,it would be worth it.


waltonjr1
Member
posted December 22, 2003 06:09 PM
106 is probably the centerline.Its probably advanced 4 degrees from the factory.That would make the seperation 110.Alot of cam cards dont list the sep.,they just give you the centerline and leave it up to you to figure out.Just my guess,I could be wrong.

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DEANJR#22

[This message has been edited by waltonjr1 (edited December 22, 2003).]

wrenchturner10
Member
posted December 22, 2003 07:07 PM
ACTUALLY THOSE HYD CAMS ARE A CRANE SATURDAY NIGHT SPECIALS COMPARE AND YOU WIIL SEE JUST DROP THE 915- WE HAVE RUN ONE OF THOSE TWO CAMS AND WAS A REAL STRONG CAM I KNOW IT WILL TURN 6900 ON A 3/8 MILE ASPHALT ON 86 INCH TIRES AND A 600 GEAR AND ON A DIRT TRACK WITH 90 INCH TIRES AND A 620 THIS CAM WAS EVEN RACEY WITH SMOG HEADS

[This message has been edited by fastrack1 (edited December 22, 2003).]

Winland Racing
Member
posted December 23, 2003 09:19 AM
Most tracks I run are 3/8. Very sloppy in the first 50 or so laps then the track comes around. I want to be able to rocket out of the turns then let off about 3/4 down the strait away. I have been running the powerglide in 1st gear but blew my motor on lap 280 leading the pack in October. I think I will start using 2nd gear next year.
Thanks for the input. Any other suggestions on cams? What are most of the pure stocks using? I want to stay with hydraullic due to the ease of tuning it up.
WR
#66


Raz_900
Member
posted December 23, 2003 09:41 AM
Single 2" pipe? You mean it's Y'd with the whole motor going through a 2" pipe or dual 2" (one each side)?

Either way, look for a cam with significantly more exhaust duration/lift than intake. 10 degrees should be good, but I'd watch to not cam it too high. With a restricted exhaust, it's not gonna want to spin really high. I'd aim for 5800-6000 max and tune the gearing/cam to make the best of it. Cam in the order of 230/240 @.050" with the most lift you can get and 110-112 LBA should work nicely. I think retarding the cam gives more idle vacuum, but could be wrong. I know it'll move the powerband about 50rpm per degree, so that would help a smaller cam on the top end.

Winland Racing
Member
posted December 23, 2003 01:10 PM
quote:
Originally posted by Raz_900:
Single 2" pipe? You mean it's Y'd with the whole motor going through a 2" pipe or dual 2" (one each side)?
Yes 2 pipes into 1 at the collector. Using stock manifolds, 1 muffler.
Thanks,
WR

Either way, look for a cam with significantly more exhaust duration/lift than intake. 10 degrees should be good, but I'd watch to not cam it too high. With a restricted exhaust, it's not gonna want to spin really high. I'd aim for 5800-6000 max and tune the gearing/cam to make the best of it. Cam in the order of 230/240 @.050" with the most lift you can get and 110-112 LBA should work nicely. I think retarding the cam gives more idle vacuum, but could be wrong. I know it'll move the powerband about 50rpm per degree, so that would help a smaller cam on the top end.




dan ferry
Member
posted December 23, 2003 06:59 PM
your definetly gonna need to gear car to turn probably 5600 range with single 2" exhaust. your gonna need a cam with less duration than your planning duration kills low end and thats what you need. with those rules one good thing about it is engines last longer and wont need alot of fancy parts. if u can run 305 heads id try to find some i beleive it the 601 castings off of 80s z28 they make great compression and low end power but may cause u to need to run race fuel. then get a cam ground to your combo and rules


rico 08
Member
posted December 24, 2003 12:54 PM
If you're dead set on a speedway cam,jump down the page to the non-oval track hydraulic's,the 915-113434 is really close to what the other cam was,plus it will be alot more vacuum friendly with the 114 lc.


Winland Racing
Member
posted December 30, 2003 09:01 AM
Bleed down lifters?
It looks like these are used to mellow out a radical cam at idle, but then kicks in at higher rpm.
At what point would you look at installing bleed downs as opposed to regular lifters?
Thanks again,
WR
#66

[This message has been edited by Winland Racing (edited December 30, 2003).]

rico 08
Member
posted December 30, 2003 03:51 PM
Bleed down or variable duration lifters were designed for street cars with big cams to get some driveabilty out of them.They are a compromise to say the least and in tests i've read you never get all of it back,so they probably won't pump back up all the way,but it works good for a vacuum rule.


Winland Racing
Member
posted December 31, 2003 06:16 PM
I am currently emailing the guys at camcraft. I found some great archives on this sight. Hopefully they will steer me in the right direction.
Rico, Thanks again. Your replys are always timely and informative.
WR
#66


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