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Discussion Starter #1
What is a good RPM range for a muscle car? A lot of the cams I am seeing have a operating range that start around 2500RPM or higher. That seems really high to me for a street car.

Does the operating range of a cam dictate the idle speed of the engine as well? If the operating range of a cam was 2500-6500 RPM. Does that mean the idle speed has to be around 2500 RPM? Or is that just the range that it starts to produce power. Would I be hurting the engine if it is below the intended operating range?

Also, if the operating range of a cam is higher, does that mean the car is harder to drive with a stick. Like is it hard to pull out from a stop if the operating range is higher than normal?
 

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If this is for a small block Chevy, the first thing to know is the range given by cam manufacturers is typically for a 350. So the range will be lower in a larger engine, and higher in a smaller one. Not sure how it would work for big block, Ford, Mopar, or other GM engine families.

As for idle, I'd say most "2500-6500 RPM" cams will idle OK at 1000 RPM, but will be "soggy" until at least 2500 RPM. The stated "range" is where the engine will make most of its power. In other words it should start pulling well at 2500 and fall off at 6500. But attaining power at 6500 also requires the proper intake system, heads, and exhaust system.

Good chart below for choosing cam duration based on engine displacement and desired RPM range. Be realistic about where your engine will spend most of its time, and whether or not the other components can support RPMs above 4500-5000. For example a 230-240 degree cam in a stock 350 would kill power below 2500-3000 RPM, but the engine would NOT support revs above 4500-5000. So you'd end up with a pig with a lumpy idle.

 

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Discussion Starter #3 (Edited)
I am building a 383 stroker out of a chevy 350. I am currently looking at two cams for possible candidates.

Howards Cams 110041-10 1955 - 1998 Chevrolet 262-400 Hydraulic Flat Tappet 1800 to 6000 Camshaft

and

Howards Cams 110051-10 1955 - 1998 Chevrolet 262-400 Hydraulic Flat Tappet 2800 to 6200 Camshaft

I'm think the first one with the RPM Range of 1800-6000 will be more useful for my uses. Good low end torque for whipping it from stoplight to stoplight.

Also what's a good rpm range for a "sunday car". I want a car thats highpower but also driveable. Should I go for a RPM range thats even lower than that if thats my intended purposes?
 

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What is a good RPM range for a muscle car?
Although some cam grinders will tell you that their cams will have an operating range over a span of 4000 or even 4500 rpm's, realistically the true effective range is about 3500 rpm's. It'll make good power from 1000 to 4500 or from 1500 to 5000 or from 2000 to 5500 or from 2500 to 6000, etc., etc.

A lot of the cams I am seeing have a operating range that start around 2500RPM or higher. That seems really high to me for a street car.
I think 2500 to 6000 is realistic. You could run a manual trans with it or you could run a 3000/3500 stall torque converter with an automatic which would allow the motor to come up in revs and "get up on the cam" to move the car. With a manual trans, you just slip the clutch a little and rev the motor a little when moving from a standing stop. Any cam you bolt into the motor will have its good points and its bad points. There is no "one size fits all".

Does the operating range of a cam dictate the idle speed of the engine as well?
Yes, as the grind becomes wilder, the idle speed will have to move up. A lope is simply the sound of a motor being inefficient. It is the sound of a motor with a cam that is too large to be operated at a low rpm. What happens is that the intake closing point on the cam is extended with a hot cam, to the point that the intake valve does not close until the piston is well up in the bore on the compression stroke. This allows the piston to push some of the mixture that has just been drawn through the carburetor and into the cylinder.....back out of the cylinder and back up the intake tract, past the venturi again and back out the top of the carburetor body. You can see this phenomenon, known as standoff, at night under a strong light shone on the carburetor. As the fuel slug is pushed back out the carburetor, it passes the venturi again, just like it did going into the motor. The venturi doesn't care which way the fuel slug is going, it sees a depression and adds fuel to the slug. Then, on the next intake stroke of the motor, the fuel/air slug is sucked back down into the motor and.......yep......you guessed it, the venturi adds more fuel. Well, by this time, the slug is waaaaaaay rich and the motor cannot idle cleanly. This is why you will see heavily cammed motors going rump, rump, rump and why the car owner has to continually blip the throttle to clean out the motor so that it will continue to idle. Otherwise, if left alone, the motor will load up with fuel and die.

If the operating range of a cam was 2500-6500 RPM. Does that mean the idle speed has to be around 2500 RPM?
No. Normally, with a stock cam, you will be idling around 600 rpm's. As you go wilder with the grind, you will have to move up to 700, 800, 900 or maybe 1000 rpm's because the cam just will not idle cleanly at a lower rpm.
Back when I was a kid, we used to idle through Shoney's with the choke on to make the motor rump-rump. hahahahahahahaha

Or is that just the range that it starts to produce power.
A cam that makes power from 2500 to 6000 won't make enough power to pull the hat off your head under 1000. This is just my opinion and has no scientific fact attached.

Would I be hurting the engine if it is below the intended operating range?
You won't hurt the motor or the cam, but you won't be doing fuel mileage any good. This is one of the things I try to impress on fellows who plan to use an overdrive transmission and cruise at 2000. If the operating range of the cam if 2500 to 6000, then you are just kidding yourself that you're going to make additional mileage with that hot cam. Nothing could be further from the truth. You should have used a cam that makes power from 1200 to 4700, so that it's "up on the cam" and in its efficiency zone by 2000.

Also, if the operating range of a cam is higher, does that mean the car is harder to drive with a stick. Like is it hard to pull out from a stop if the operating range is higher than normal?
It takes a little getting used to. You just rev the motor a little higher and slip the clutch a little more.
.
 

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A cam that makes power from 2500 to 6000 won't make enough power to pull the hat off your head under 1000. This is just my opinion and has no scientific fact attached.
:thumbup: Very funny.

And that's some informative stuff you posted about why cams lope.
 

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Discussion Starter #7
My setup is as follows:

-Wiseco Flat Top pistons
- AFR Aluminum 195cc heads - 75cc Chamber. https://www.summitracing.com/parts/afr-1036
- Compression ratio of 10:1
- 4 Speed Muncie manual
- Going into a 69 chevelle
- Do not know the rear end ratio yet. Gonna go with something mild and able to drive at highway speeds
- Do not have carb picked out yet. Will vary depending on everything else
 

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Howards Cams 110041-10 1955 - 1998 Chevrolet 262-400 Hydraulic Flat Tappet 1800 to 6000 Camshaft

Is this a good option for my intended purpose? A sunday car that has some balls from stoplight to stoplight with highway ability?
279/289, 225/235, 0.465"/0.488", 106 intake centerline, 110 lobe separation angle, 114 exhaust centerline, 1800-6000 operating range, fair idle, Hot Street & mild Bracket Racing.
Will need 9.5:1 to 10.5:1 static compression ratio. Stay at 9.5 with iron heads, go to 10.5 with aluminum heads. Will want low rear gear, like maybe 3.73:1 with a 27"/28" tire.
Read through this tutorial that I wrote several years ago to learn how to make your flat tappet cam surive in today's roller tappet world. Motor will want minimum 750 carb, 1 3/4" long tube headers. Install X or H pipe immediately after the collectors, then through mufflers of your choice to the rear bumper. Pipes that are terminated under the vehicle sound Mickey Mouse and identify you as a fellow who didn't know any different. Use a 14" x 4"air filter assembly so the motor can breathe. Cut the block decks to zero and use a Fel-Pro 1003 head gasket for a squish/quench of 0.041" to prevent detonation.
http://www.crankshaftcoalition.com/wiki/Camshaft_install_tips_and_tricks

.
 

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Discussion Starter #9
So many factors to account for! Woo getting a little overwhelmed ;)

Yeah the 4 speed on the highway is definitely going to be an issue. But just to make sure the cam I'm looking at is enough to "make my hat fly off"?
 

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hat fly off cams do not usually come in the form of hydraulic flat tappet. Any other type of cam will make more horse power.

I'm having to post about rear gears again;
rear gear ratio by itself has zero affect on how the engine runs, period. Steeper gears are usually associated with drag type racing. example,,, If you go with 4.10 gears and a Muncie close ratio transmission you would have a good combination for a tight road race car but a terrible combination for a drag car or street stop light to stop light car. Same car with a wide ratio Muncie and 4.10 gears would be ok for a tight track road race car, not bad as a bracket car and decent to good as a stop light to stop light car.

The rear gears and transmission combined with tire size is the combination you need to worry about for the "cars" purpose. The engine and its power band should fit the "car" and its use. Adding rear gear just because you installed a big cam is a very bad choice made to crutch a poor combination.

If you are building a car for dead stop acceleration then a rear gear change is usually welcome, especially in fat north American cars that are way over weight.
Consider using a stronger and more versatile 5 speed instead of the Muncie. If you insist on the Muncie then contact "autogear" for help to strengthen your transmission to live behind some power.

Buy a scattershield
 

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If you insist on the Muncie then contact "autogear" for help to strengthen your transmission to live behind some power.
Check out the M22Z here: Muncie 4 Speed Transmissions and Parts

I think it uses an Auto Gear gearset made in Italy. The 2.98 low gear makes it easier to run a taller final gear and still have enough torque multiplication to easily get moving in first gear. And the wider ratio between 1st and 4th is still closer than a lot of 5-speeds.

I almost pulled the trigger on a complete M22Z trans as an alternative to a Tremec 5-speed. The 5-speed would have required a new clutch disc, shifter, shorter driveshaft, and mods to the transmission tunnel. I ended up staying with a stock M20.
 

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The Muncie,2.98 2.04 1.47 1.00 spread is similar to the TKO 600 without the very use able .82 5th gear at about the same price.

If the new Mustang 5.0, 6 speed if it was a tough transmission I would recommend it. It has a deep first gear that would work well with 4.30 gears paired with a strong 7k rpm engine for street/strip and it has an over drive that's .68 ish.
I think the day of the 4 speed is dead for a serious anything,,, All the way back to the early 60s one of the biggest complaints was GM did not have a 5 speed or disc brakes(LeMans cars)
Ford has a 10 speed auto,,,
 

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Howards Cams 110041-10 1955 - 1998 Chevrolet 262-400 Hydraulic Flat Tappet 1800 to 6000 Camshaft

Is this a good option for my intended purpose? A sunday car that has some balls from stoplight to stoplight with highway ability?
This cam is similar to the stock cam that came in 350 HP 350" engines in the 1960's... it was intended for use as a higher performance daily driver in an engine with 11:1 compression ratio... The HP was limited to 350 HP by the stock heads, but the cam can make 450 - 500 HP with better flowing heads...

We don't usually pick a cam by RPM range, but by the combo of desired HP, torque, intended use, vehicle weight, rear tire size, vehicle wind resistance, drivability, MPG, etc... and the RPM range is just whatever that cam that fits our purposes needs to run in...

If our purpose is a budget street performance car with good drivability then we will prolly aim for 600 - 6500 RPMs range (which fits your cam choice) since that is compatible with an engine with mostly stock parts in it... going higher in RPMs has costs that add up quickly...

GM sold cars for daily driver use with 2.21 - 4.33 rear end gears... but getting over about 3.90 rear gear produces a vehicle where the engine buzzes at a rather high RPMs on the hiway... and wears out faster... but we lived with it back in the 1960's when overdrive trannies were rare and mostly not an option... drove them coast to coast...

The 225/235 cam you linked above looks about right and max size for your purposes and compression ratio... since you are going high dollar on the heads, you might also consider going roller lifters/cam of similar spec.s...

The rear end gear will depend on the vehicle weight and desired rear tire size...
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Here is a brief rundown on my two small block chevy builds. As you can see on my lunati hydraulic roller cams I have the milder one and then in my slightly wilder build I have the voodoo cam that is the next step up on the list.

On my 96 s10 which is the milder one it idles about 800 rpm in park and drops to about 600 or so and it has a faint lope to the idle but nothing radical with about 17 inches of vacuum and drops to about 14 in gear. My compression ratio is slightly on the low end of things for the cam in my 86 s10 but it still overall runs really well but its not something you would want be in stop and go traffic. My 96 s10 can go through some stop and go traffic here and there but its not something for short distance travels everyday.

The throttle response on both trucks My 86 s10 idles at 1000 rpm and drops to about 800 rpm in gear and does have a racy idle to it and you can tell its way more then a entry level performance cam. I have about 12.5 inches of vacuum in park and goes down to about 9 inches of vacuum.

Both trucks run pretty well and does not take hardly anytime at all to get them into the performance rpm range while shifting from first to second then to drive. At about 3000 rpm is when it comes on strong and both pull past 6300 rpm with no problems and levels out after that and it drops within the torque range with that shifting point.

96 s10 9:1 compression
Lunati voodoo hydraulic roller cam 270/278 219/227 @50 515/530 lift 112 lsa 1800-5800 rpm range
weiand high rise intake dual plane with holley 650 double pumper
Dart shp 180cc aluminum heads.
scat cast crank and scat rods 3.480 with 4340 capscrew 5.7 connecting rods
Decked block for approximate .040 to .050 with head gasket and torqued
Turbo 350 transmission with shift kit and 2000 to 2200 rpm stall convertor with 3.42 rear gears

86 s10 9:5 to1 compression
Lunati voodoo hydraulic roller cam 282/290 231/239 @50 535/550 lift 110 lsa 2400-6200 rpm range
weiand high rise intake dual plane with holley 650 double pumper
Dart Iron eagle fully ported and worked over iron heads.
scat forged crank 3.480 stroke with 5.7 h beam connecting rods capscrew style
Decked dart shp block for approximate .040 to .050 deck height with head gasket and torqued
Turbo 350 transmission with shift kit and 3000/3500 rpm stall convertor with 3.73 rear gears
 

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Check out the M22Z here: Muncie 4 Speed Transmissions and Parts

I think it uses an Auto Gear gearset made in Italy. The 2.98 low gear makes it easier to run a taller final gear and still have enough torque multiplication to easily get moving in first gear. And the wider ratio between 1st and 4th is still closer than a lot of 5-speeds.

I almost pulled the trigger on a complete M22Z trans as an alternative to a Tremec 5-speed. The 5-speed would have required a new clutch disc, shifter, shorter driveshaft, and mods to the transmission tunnel. I ended up staying with a stock M20.

Thanks for the nod Vinnie and 55 327! We do supply a lot of parts to Paul at 5speeds.com He also wrote a very good book on the Muncie 4 speed.

I do a lot of M22z conversions for people who want to run down the highway at ~2300-2500rpm with a 3.08 or 3.23 rear gear; and keep the flavor of the 4speed, along with the fitment and quick shifting. Vinnie is correct, a 5speed has its place; as long as you nail down the 1st gear-rear gear-tire height-overdrive compromise.
Personally, overdrives are a compromise in a lot of respects...and I think Doug Nash was closer to the mark with the 4+1 direct drive 5speed. Direct drive transmissions will be inherently stronger and quieter in 5th gear than their overdrive counterparts. Also, driving a 10-speed manual gets old in a hurry for most people - the reality is a torquey v8 with a carb doesn't need a lot of gears, its not a 2L Honda and the carb can really struggle with a single overdrive in a bad combination, adding a .50 6th is asking for a lot of trouble for the guy trying to "fit" an OD into his equation.
If I was going to design a single 5speed with OD; it'd probably be a 2.56/1.90/1.36/1.00/.80 or a 2.56/1.75/1.36/1.00/.80. These would pair well with everything from 3.55s to 4.10+ and it would have a lot more strength, and less feedback in overdrive. Its hard to sell people on a mild overdrive, the interwebs and catalog salesmen insist on the easy sell. "Deep 1st gear and deep overdrive." It covers every rear axle ratio imaginable and whether or not the car is actually efficient in 5th gear (as per Tech Inspector) is a moot point. As long as the car doesn't fall on its face when you shift into 5th, or chug so hard it beats you to death...Joe Lunchbucket will trundle down the highway happily unaware, and the catalog guy gets his commission.

The Z-set can be had from a number of sources; you could even put that gearset in a stock case if it had a 1" countershaft pin bore and the case was in good shape (press fit between the 1" dia countershaft and its bore are important).

If you want a list of approved vendors, or part numbers - just ask.
Nathan
 

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Its hard to sell people on a mild overdrive, the interwebs and catalog salesmen insist on the easy sell. "Deep 1st gear and deep overdrive." It covers every rear axle ratio imaginable and whether or not the car is actually efficient in 5th gear (as per Tech Inspector) is a moot point.
Well said. I never did understand a .50 or even .68 OD gear. I expect there's a lot of guys out there who have to keep the trans in 4th at anything below 70 mph.

If I ever get a Tremec 5-speed it would be the one with the 2.87 to .82 spread. It would knock down highway revs from 2500 RPM to 2050, or from 3000 to 2460. Another way of looking at it is a 3.55 axle becomes a 2.91 on the highway, and a 3.90 becomes a 3.20.
 

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Mild cam and/or good carb/ignition tuning are a must.

Hotrodding has always included putting modern stuff in an old car. However, a lot of the 6 speed conversions are done behind healthy motors with BIG cams, BIG carbs, single plane intakes, and less than stellar ignition curves. The more time we spend in our plastic bubble cars, the more our bodies feel the need to go down the highway at 1600rpm.
However, transmissions do not exist in a vacuum. 6 speeds were designed for OE-level, complex EFI. In fact the Borg-Warner T56 was originally the T55 5speed. It was the CUSTOMER who insisted on the double overdrive.
You need to look at the SIZE of a 6 speed, take into account the short driveshaft (changing the driveshaft angles), the increased shaft speed. In addition to shortening the tube, you may need a thicker wall.
You need to look at your engine, if its a race-bred engine, it may not run well below 2500rpm. You need to look at your rear axle ratio, if you spent a pile of money on a 3.55 rear; adding the wrong overdrive becomes a really expensive endeavor, now you need the more expensive transmission, different driveshaft, slipyoke, ujoint, shifter, possibly bellhousing AND to bump your rear gear UP enough to use the overdrive.

In a worst case scenario, I had a customer with an early corvette, with a SERIOUS bigblock, dual quads on a tunnel ram. He wanted better fuel economy (stop. its a big block with a cam thats from the bottom of the page in the magazine). He picked the TKO500, 3.27 1st and the .68 overdrive. And it was slow shifting and miserable on long drives, AND way more 1st gear than he wanted. Since we handle some tremec stuff, he got our name. I asked him to just TRY keeping it out of 5th gear on the highway for proof of concept. Highway manners improved markedly, and the fuel mileage actually improved slightly.
In his specific case a 2.88+ 1st gear 4 speed was the best fit for HIS application.
The moral of that is: Take your time and use a systems approach. Everything has to jive.

Lets get back to cams!
 

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Mild cam and/or good carb/ignition tuning are a must.
Some guys would hang up the phone if they got a street cam recommendation from Mike Jones at Jones Cam Designs. For a 327 with 9.4:1 compression and Brodix IK-180 heads, in a 55 Chevy with M20 Muncie and 3.08 axle, he suggested this flat tappet hydraulic cam: 260/264, 204/208 @ .050, 110 LSA, .443"/.449" lift.

Sounds very un-hot rod like, huh? Needs to be more like 212/218, or even 218/224 @ .050"right? Well, he said the heads flow well enough that they don't need a lot of duration, and that a 327 likes a lot less cam than a 350.

Performance turned out to be exactly what I was looking for. Lots of torque from 2000-4500 RPM, with a killer hit at 2500. It would rev to well above 5500, but I rarely went there. And no nasty manners below 2000 RPM, so I didn't have to downshift to first gear as much as I did with my old cam.

I think performance ended up being somewhere between a 300hp/327 and a 350hp/327, maybe even closer to the 350hp/327 due to the heads and modern cam lobes. And it didn't need a 3.70 axle or 11:1 compression to work.
 

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Jones cams are always a little smaller than the competition; something about the ability to grind an inverse radius on the lobe.

Chris Straub is a custom cam grinder and valvetrain specialist who has offered up a lot of first hand knowledge on this board as well.
 

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Trust me on this it is better to be conservative on the cam size then being a little to big or just overkill as I have done that mistake several times over the last 16 years on different builds. I always go for a little bit lesser cam wise and try to match things real well and for honestly of what I will be doing with my ride more so then for how it will be at a dragstrip since I don't take it there. Its always more fun and good when everything from top to bottom is matched well for what your looking for. Don't take any old cam and say well that will be good enough. A lot of different cam grinders can really make you something that is better then just pulling something off the shelf. Some of the advice from some of the others above is like gold and you can't go wrong. Good luck on your build
 
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