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Post by garage1 on Dec 23, 2012 5:28:31 GMT -6
we're new to this , whats the best cam, we run a 1/4 and 3/8 mile tracks, with no vacuum and compression rule
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Post by billy5x on Dec 23, 2012 10:14:31 GMT -6
howardscams.com
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Champ2x36
Pit Crew
Just an old racer!
Posts: 10
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Post by Champ2x36 on Dec 27, 2012 21:22:40 GMT -6
Howards Cams and Isky both have a selection of lift rule cams.
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Post by Krooser on Feb 18, 2013 22:12:16 GMT -6
www.camcraftcams.comCharles has killer cams for lift rule tracks.... and he will custom grind whatever you should have...
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Post by rwilliams on Mar 11, 2013 17:48:25 GMT -6
We use Howards off the shelf lift rule cams as we have a 425 lift rule and have had excellent results. Excellent product for the money and a little bit cheaper than the other brands by 50 to 75 bucks or about enough to by their race hyd lifters another product that is excellent in my book. ;
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Post by racenmotorsports on Jul 18, 2013 13:02:23 GMT -6
I used the isky sl1 cam. Worked great for me.
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Post by flipflopoo1oo on Mar 9, 2014 18:22:09 GMT -6
I am not spoiled on any names but I do want to hear all the specs. as to application in stroke verses bore and gears as well as the weight and rpms desired on what length of track, engine compression ratios and intake cooling capacity, type of fuel you want to buy! This call comes into a cam!
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ss47
Pit Crew
Posts: 1
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Post by ss47 on Mar 25, 2014 17:03:54 GMT -6
I am not spoiled on any names but I do want to hear all the specs. as to application in stroke verses bore and gears as well as the weight and rpms desired on what length of track, engine compression ratios and intake cooling capacity, type of fuel you want to buy! This call comes into a cam
WHA?!?!
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Post by flipflopoo1oo on Mar 25, 2014 19:34:07 GMT -6
The weight of the class, gears for the pulling range on the length of track, engine design, and all the info comes into picking out a good cam! Most have to feed all the info in to get the correct cam for your application to get it close and then its a matter of degrees to fine tune! Most cams worth having are hard to find unless you already know what to look for because they have tons of cams they need to sell! I run nothing with less than a 110 lobe separation for the simple fact of getting the exhaust closed sooner as not to be pulled it in with the gasses so much as to loosing horses and torque in vacuum loss! A split in duration and lift of 5-7 and 7-12 will give better flow also! I have picked a few winners and they disappeared as the companies were promptly bought out as to sell other cams already ground! Most don't want to give out all the specs on there best cams until bought! Duration at 50 will give some clues as to torque at the low end! 1.6 rockers always is a plus if figured into the geometry correctly as it tends to give a faster ramp speed in getting things open and closed! A total package to get the most of what fits the car and engine! Its a big world to choose from!
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Post by ssm31 on Mar 25, 2014 20:21:27 GMT -6
You talk about split duration, which I believe as well is very important but with split duration your lobe seperation will drop several points. So it will be difficult to stay above 110. But with that amount of lift I don't believe the lobe seperation is a factor
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Post by flipflopoo1oo on Mar 26, 2014 7:08:17 GMT -6
Every thing is a factor and the lower lifts needs more duration to make up for loss of lift, but the numbers at 50 is where flow actually starts taking place! At 20 with larger valves with smaller stems and porting on longer stroked engines with more vacuum! Asymmetric cams has helped to allow more, sooner, and close quicker with more separation as does 1.6 rockers and lighter moving parts in the valve-train!! Spring tension is most critical to keep up with closing ramps as not to destroy the cam at high rpms! Where do they tech the cam? At the cam or lift at the valve? I have ran lash on hydraulic stock lifters and sacrificed lift and duration to put specs where they needed to be on a 450-12 at 1200 vacuum rule to produce more torque to win 3/4s of our races only turning 6400 rpms. A gear and cam degree change had to be made from turning 7800 but it was faster loaded with more torque applied while staying in the peak pulling range of this design of a sorry cam! Geometry at the valve is a long way from a cam's design! Different compressions and fuel used is a key factor on cam designs also! Pump gas is cheaper by far in a season of racing and can keep you on newer tires or pay for a extra hot dog or three! I do not want exhaust sucked in, so closing while movement is higher helps! I want cool fuel and air to build more compression by its expansion, so getting the valve closed quicker helps the compression ratios of low compression engines to fly by not having to compress so much and at the same time delaying burn timing to burn a longer, hotter burn stroke with out stroking the engine! Its like a game I play in my head of many factors and it gets complicated for this old country boy with grease on my hands and a extra horse in my pocket! If I have a clue, its just because I have paid attention and questioned everything that moves! A curtain exhaust closing number at the valve,(every valve, as all vary quite a bit if tested at the valve) is a key factor in horse power! Its like trying to find and know where roll centers are during a race! It to changes and needs adjustments often like jetting and temps or timing and traction!
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Post by flipflopoo1oo on Mar 26, 2014 7:44:02 GMT -6
After reading my own post and trying to clean it up a bit, I know the first thing that comes to mind is trapping more exhaust by closing quicker! Degree on the cam and jetting ratios as well as fuel octane is now in the factors as always but can be addressed more easily than designs of cams! A tune from start to finish!
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Post by Krooser on Mar 27, 2014 21:55:56 GMT -6
Camcraft grinds some great two barrel limited lift cams… and Charles has great 'backwards' grinds where the exhaust duration is shorter than the intake to help negate inversion...
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Post by flipflopoo1oo on Mar 28, 2014 9:35:54 GMT -6
A hyd.318-336, 450 lift pulling 12.25 inches of vacuum after the race on a clean hot engine is a trick in it's self and I doubt they would have a clue as to how to grind that into a cam and I am not wanting them to know how! A 50 horse advantage is hard to come by these days! I can probably boost most any engine more horses straight off a three week Dyno! We have had too, to win with what you run against these days! I have never been a fan of high dollar parts as most are name and a pretty box with stickers inside! How much does aluminum weigh any-how, what good is less turning weight against higher compression, what good is a heavy balancer to keep it from breaking if it only pulls every other vibration through the engine to be dissipated! Give me turning momentum and harmonics to repel friction and heat energies of static magnetics most any day! NF is 4 pounds lighter than a steel crank, more flexible at high RPMs! I run no balancer only a hub, My belt does the dampening! 305 x rods polished only to add strength are lighter! A light weight set of wrist pins is most of the lighter piston weight or just saw yours off! There is horse power to be had every where you look! If you look! Polish every moving part but by the rules to win or you haven't done a thing! Really! How many can say they have won with out cheating and lapping the field! You will the checked and DQ-ed for any infraction after winning a few, like 16 in a row with out cutting them no slack at all! When other big track owners call and give a bounty on there guy to sush the crowd on there top winning guy, and you do two nights running with two different cars and drivers one at a time, that is fun at its best! Its more about tuning any cam to better fit each cars needs! I would hate changing cams between heats and main events to be faster, that would be like having to change my set-up from track to track! It don't need to happen! Just let me eat another pork chop and you drive, is time well spent at the races! Its no fun watching one car way out in front! You don't need to win every lap to enjoy a clean race, side by side 20 laps from flag to flag! Its the last ten yards that counts with-out tearing something up as to leave time for more tune back at the shop! A different cam in most every engine we ever ran for a season! Too many factors to deal with using the same one in any given block, so why not try to improve on any changes made if you have the ideas and time to do so! It only took me 60 years to get this far but I am here to help you pass on the high or low side!
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