Let's play "Help Bryant pick a cam " !

[Bryant Fields]

Ok guys, Your opinion matters. Thats why I'm coming to you for suggestions. It's time for a new cam, and I wanna go bigger. But I also don't wanna go so big that I'm backin' up. Here's what I have now:
290 adv, duration, 550 lift.(that's all I know about it) I have an oddball combination of 1.6 intake and 1.5 exhaust Harland sharps.This gives about 580 on the intake. I'll be changing one half of that combination of course.
When choosing the new cam, heres the stuff that matters: Pistons are flat top with valve reliefs (originally Arias domed tops, had to be cut for the closed chamber heads);
915 heads (big valves,3 angle valve job, pocket porting,gasket matched, basic bracket racer stuff);Torker w/ a 1050 dominator (occasional N2O used); 2" primary hookers/3 1/2" exhaust with 3 1/2" flo's;3500 stall 727; 4.56 w/ mini spool,moser axles amd 28''tires; 68 barracuda wieghs a maximum of 3300 with my fat ass sittin' in it and fuel cell full of av gas.
What a mess right ? Ok, lay it me....Your two cents worth would be appreciated.

[Dave A]

Bryant,....OK let's answer a few more questions. How much static compression do you have and what is your displacment? Is this a street/strip car or just race? If you change cams you're going to change valve springs too. Have you cut the cyl head spring platforms for larger (dual/triple) springs yet? How much air does the Dominator actually flow? What E.T. and speed are you wanting to run? BIG mph and low E.T. require more rpm's, less weight,... more money. Remember the car also has to be upgraded when you get the motor stout enough to make those BIG SMILE "top-end charges".

[Fury Boy]

call engle and ask for there K10, www.englecams.com

[Streetwize]

What RPM are you running through the traps and what is your ET/MPH and what is your 60 foot time? From this we can get some idea of your acceleration curve. 4.56 gears and a 28" tire is roughly 112mph @ 6200RPM (with zero slip). If you have a stout motor in a light car you may have too much gear. 112mph @3300lbs is roughly 358@the wheels or 430 @ the crank. How close are you to that?

I really can't zero in a cam unless I know what kind of head flow you have. Pocket ported 915's can go anywhere from 225I on a bad backyard port job to all out race w/epoxy=thin 270+cfm. A Dominator with a Torker is not an ideal combo due to the small manifold plenum and less-than-great distribution on that piece, you may try to borrow an M1 single plane from someone to make a couple passes before the cam swap. You don't want your cam writing checks the top-side of the motor can't cash. anyway. 550" with 290 duration sounds like it's probably a solid. The Torker itself may be holding you back

See if you can get some more info and we'll see what we can come up with.

Streetwize

[HOLESHOT]

CHECK OUT THE ARTICLE IN THIS MONTHS CAR VRAFT ON THE 360 CAM DYNO TEST AND YOULL BE IMPRESSED.

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[Bryant Fields]

First of all, thanks for replying to this. Dave ,I really dont know what the static compression is, or how much the heads have been shaved or the block decked or even the gasket thickness for that matter. Would a compression test help give me the info I need ? This car sees very limited street use. As for the valve springs, That's what started the whole thing. Theyre probably gettin a little weak as the car had sat unused for a long time,(built a house and a family) and the last time I ran it I noticed it had fallen off on the top end and seemed to be popping a little through the traps. So, even if I dont get a new cam the springs at least will be changed.
The dominator; I cant tell you what it actually flows. and I havent ran it on the car at the track. I had a 750 vacuum sec. when I ran it before. I did drive it around town some, did fine and man , what a difference out of the hole ! using the formula I found in a magazine (rpm&cubes , etc..) came up with 915 cfm needed, so I figured that it wouldnt be too much over kill. Only future time slips will tell. RPM&ET? I wanna keep the rpm's under 6500, have turned 7K before but I know that would be a deathwish for my bottom end . we only have 1/8 mile tracks here was running 7.60 with 1.80 60 ft's (spinning some) w/ the 750 and 4.10 gears and 100 deg air. I'd really like to get it to make some 7.0's in good air.
Furyboy, thanx, gonna call'em today.
Streetwize, in the previous mentioned passes, with those conditions it was turning about 5200, and seemed to be flattening out( I think bcoz of the springs, or maybe the ignition was a contributing factor also).
The heads; for all practical purposes , lets just assume they are stock w/ bigger valves.it wasn't a back yard job but I'm sure theyre not all out jobs either. The engine was built by a very reputable speed shop, but they werent mopar guys either. Just a good "cleaning up" . As for the torker, I always thought they were pretty good. I remember reading in the older D.C. books that the only one at the time that was better was the holley, but they said it wasnt enough better to change. Of course that was way before the M1 stuff came out . So, if the mopar piece is that much better, It'll be on there soon. Your right, the cam in it now is a solid. The engine builder had it there bcoz someone ordered it and didnt come back, so he made me a deal on it. Hey, I was only going bracket racing at the time! I was alot younger and naive at the time, and was being Advised by older mopar racers.( thats where the split rocker ratio Idea came from ....$#$#$#@!!!)
oh yea! another thing that might help.. when this motor was fresher( better valve springs) I had it in a full bodied Road Runner with 486 gears and it ran a best of 7.49. put all the info into the moroso power speed calculator and came up with 425 hp. Thats what it takes to get that number but theres always wasted hp through the driveline and stuff. Well guys, I hope I've answered some questions. Thanx!

[Streetwize]

I'd give Tim Goolsby @ UltraDyne a call, he's VERY knowledgeable and has always been right on the money. If you have 10.5-11:1 (with 915's that's usually a pretty safe bet!) and your heads are above average (somewhere around 255+ intake)I'm thinking a .904 solid with 265-270 degrees @.050 and around 585-600 lift on 106 in @ 106 (for 1/8th mile) and an M1 with the dominator flange. That tight lobe center will make a TON of midrange, just about perfect for short strips. This should be a good combo, watch your piston to valve 'cause 106 brings a bunch more overlap!! Get a big tach 'cause your shift points are gonna come at you fast! If you can get the heads on a Flowbench we can get a more accurate choice.

Lunati has got some particularly nasty and succesful Cheater grinds if the car is for the strip only, you wouldn't run'it on the street though.
They're low (~465"lift) but nearly roller lobes on a hydraulic blank . 1.6" will help your lift but remember these cams are pretty brutal on the pushrods and rockers.

Wize 1

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Streetwize

[Sport]

I don;t think I can get you you down to 7.0s but, maybe I can get you a tenth.First your 60 ft. could be improved upon ,that could get you another tenth.But you wouldnt; be alone alot of us could use improvement there.Streetwize,s advice about losing the torker is good. Car Craft has mag on the stand now that compares the torker flow rates to the RPM,s . Torker runner flow was 240 cfm.vs the RPM,s at 275.The RPM ported they were able to flow the runner at 290 cfm.Dont use the max,s as absolutes should go without ..... In a seperate mag they did a drag strip test of the RPM vs the torker 2. The torker2 lost almost a tenth to the RPM at the 60 ft.,but almost equaled the mph.in the 1/4. In the 1/8 the torker 2 wouldnt have made up as much.In the same mag they also compared the M1 to the RPM they were almost a dead heat .This test was done in 3900& car, in a car like yours the M1 would be the ticket,I think . I think you have plenty of cam lift to get the job done but you dont know the rest of the cams specs . Like Streetwize I also like the tight lobe seperation for midrange torque.In an 1/8 mile car torque may be your friend. It would also be nice to know the cfm of your port job. Keep us up to date on any changes you make and any improvements you get .May be some of us will follow .Its always cheaper to let somebody else to be the test subject .I almost didnt reply because there was little that I could add that Streetwize didnt cover, from my perspective.Sport

[DaMopaGuy]

Sport, Do you know what month/issue that car craft is(just bought what I thought was current)

[DaMopaGuy]

wait, Maybe I missed it but what engine are you runnin?

[Bryant Fields]

OOPS! I knew I left something out ! It's a 440.

[440 Jim]

I agree with pretty much everyone has said, especially Streetwize. However, I think that 3500 converter might be a little too small for a solid cam with 265-270 degrees at 0.050. But, since you are not hooking up the tires right now, maybe it will help that; but you really should work on the tires/suspension not over cam.

[Dave A]

Brian,... I agree with 440 Jim on you can overcam your motor. My experience or understanding is that a 265/270 @ .050" will put you too far up (5,000/7,500) in the rpm band for power. For an 1/8 mile you would need to have some ungodly high rear end ratio ~ 5.20:1 or to get the motor to come on hard and it probably wouldn't want a 3000 rpm launch. That would be about approx. 315 to 320 duration @ .009" and that is a bunch to deal with. You would need lot's of air and compression to get that to work. Sounds like Super/Gas motor territory. Take the advice of one of the folks in the list and call a couple of the cam manufacturers and see what they recommend. My instincts say a ~0.500" solid or hydraulic roller and new springs/oil seals would be better for your needs. If you get too large a lift cam you'll need to cut the valve guide stems to avoid collisions with the spring retainers/keeepers. Have the valves faced and seats kissed when you put on the new springs. Re hone and put in new rings and bearings too. No sense trying to make more power if the motor leaks. When you get the motor in the car, work on weight, pinion angle, shocks,... & upgrade to 1/2" aluminum fuel line if you don't already have one. That popping on the top end might be not enough fuel or you're correct in that the valve springs have gone away. OH, I just remembered this from a friends experience; If the motor makes a buzzing sound on top end the springs are floating.

[Streetwize]

If the cam I picked sounds big, please remember that with solids and their associated valve lash (anywhere fron .18 to .34-ish depending on MFG. and valvetrain geometry) should be deducted for comparison from the "theoretical on-paper" lift. Likewise, the .050 advertised durations for a solid typically need to be anywhere from 10 to as much as 15 degrees larger than an equivalent Hydraulic to compensate for lash. The advantage of the solid is it's ability to transfer higher rates of lift once the valves are off their seats. For example, the 265/270 solid cam I stated would typically compare to a 252-258 or so @.050 on a hydraulic, it's just that a hydraulic can't run the aggressive ramps due to the physical limitations of the fluid plunger design.

Hope it helps clarify the choice.

Wize 1

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Streetwize

[Sport]

DaMopaGuy The car Craft mag wasnt the most recent . It was the one out just prior to the current one that is on the stand now.When I was at Rite aid a week ago they were both on the stand.sport.

[quick63]

bryan do yourself a favor. give up the aviation gas. it is tough on carbs.

[Sport]

Bryant,I have had a couple of Busch Lights. So my wisdom is even brighter now, even though I have not been drinking Budweiser.Here Is my Busch light opinion,Its the whole combination you have to work on to get to the 7.0,s in the 1/8 and not just the cam .The cam you have seems plenty big, lift wize anyways. My car is in the same ball park as yours ,it was running 7.45,s@a lighter3100# .484 cam 440 RPMintake 3.91 1800 stall,9.2,comp. 9x28MTSlicks Iwanted 7.0s also.My comb.changed to the tune of lighter 2900# 509cam 440Rpm intake 3.91, 1800 stall, 10.1comp. 9x28MtsSlicks.Igot 7.12@98 in the 1/8 but this was at 28%timing I set it by ear, I was in a hurry. I think at a more appropriate timing say 36% I might have gotten into the 6.90,s Guess only, I will find out this spring.My 60 Ft. times were 1.69 for the 3100# car vs the 2900# car 1.65. Thats why I think you might have a free tenth just waiting for you in your suspension. Hear is where the cars seem to equalize add 400#,s to my car to match your 3300# witch is like adding 1/10 per 100# we are at about the the same ET. But with two differently built engines/and combo.Just Beer for thought. Speaking of witch Sport out!

[Bryant Fields]

Thanks for all the info guys, and keep it comin'. Originally I was considering a small roller, becouse I like the idea of the small duration # to lift ratio and the lower friction too. But $1000 for the setup and taking the chance of over caming for my compression ratio was kinda scary. I was also considering the Hughes cams. But I was also wondering what yall thought about the MP purple 590/312 ?

[DaMopaGuy]

Prple shafts are fine, but I know many who ran them and then switched to a 'smaller' Hughes(509 to a hughes 3038) and picked up .5 sec in the 1/4 oer best time w/ 509

[Morris Brown]

Dear what cams should i use?
if you want more cam try a cam with the same advertised duration but a more aggressive lift. all cam companies have what is called Chryslers specials which are more aggressive than just a cam there are usually 3 cams one aggressive than the other and will load your engine down with a more substantial or a lot more noticalble torque and horsepower. then you can tell all your mopar fan that there is no chevy lobs in this engine.