273 mild build cam
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roccodart440
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When are you operating the car under 1800 anyway? Never go by those numbers. I'm running a cam that says 3-7k rpm range. Cars is done making power at 5600. Makes over 400 ft/lbs at 2500 rpm. It's funny you believe the rpm range they advertise but not the "mild idle" part?
Lift has very little if anything to do with the cams idle. Duration, yes. LSA even more.
Notice this cam Crower 31240 // 214 int./218 exh @ .050. 0.455 int./0.474 exh. 112LSA has the same exhaust and 2 more intake duration than the cam he was looking at. BUT it has a little more lift and 2 degrees more LSA.
Notice the "mild idle" howards cam. All the big duration is on the exhaust valve, not the intake.
What gear ratio?
You'll want a convertor anyway but 5-10 degrees past stock duration can still run on a stock convertor but again, a custom convertor is the bee's knees.
Another you might consider is the Comp DE265H. They are ground very similar to the Thumpr cams.
Sorry, I should have looked closer to the duration numbers. I saw the lift at .500 or so and I over reacted. I can see .500 lift with a roller but not with a mild hydraulic.
xLURKxDOGx
"An angel fat, at satan's feast"
I believe it is the stock 3.23 or whatever came in a 63 signet. Does anyone know that the next step up from stick converter would be? 2500?
Jake
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pishta
I know I'm right....
Im throwing one together right now, Donated long block, swap meet rockers and I found a bumpstick on my shelf that has a .450 lift, I think its a Comp 268X so Im going to run it on 7 3/8 cut pushrods and stock hydraulic lifters with mechanical rockers. Im going to do a draw through turbo setup on it old school, and run the whole thing on a test stand for kicks. Will post vids.
Here's a little comparison. Now don't throw me under the bus on this one. I don't have my 273 on a dyno and a whole bucket of cams to try but I did fire up my computer dyno program. I used my +.030 273 with a Isky E4 as a baseline and then plugged all the cam specs in and I didn't change anything else. The actual numbers don't mean a lot but the difference in the numbers do. It's surprising how little the HP and torque increase with the bigger (higher lift) cams. I don't feel it would be worth the extra work and expense to use a .500+ lift cam to gain so little. The difference between the Isky E4 and the Crane roller is a gain of 12 hp. and 19 lb/ft for a cash outlay of $1000? Doesn't make sense. tmm
CAM__________HP/RPM____________TQ/RPM
Isky E4 286/5500 307/4000
Crower 287/6000 285/6000
Howards 291/6000 281/4500
Comp 285/6000 286/4500
20-304-4
Crane roller 298/5500 326/5500
CAM__________HP/RPM____________TQ/RPM
Isky E4 286/5500 307/4000
Crower 287/6000 285/6000
Howards 291/6000 281/4500
Comp 285/6000 286/4500
20-304-4
Crane roller 298/5500 326/5500
ddartdude
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Jake,
Since the car is a 1963 Valiant, it didn't come from the factory with a 273 in it or an 8 3/4 rear end. So how about some info on the engine you plan on using and the rest of the drivetrain.
Is the engine a HIPO 273 or a 2 barrel engine?
What year?
If you are using the stock cylinder heads, what are the casting numbers on them?
What carb and intake will you be using?
Are you putting an 8 3/4 rear in it or does it have one in it already?
Headers or exhaust manifolds?
Alan
Since the car is a 1963 Valiant, it didn't come from the factory with a 273 in it or an 8 3/4 rear end. So how about some info on the engine you plan on using and the rest of the drivetrain.
Is the engine a HIPO 273 or a 2 barrel engine?
What year?
If you are using the stock cylinder heads, what are the casting numbers on them?
What carb and intake will you be using?
Are you putting an 8 3/4 rear in it or does it have one in it already?
Headers or exhaust manifolds?
Alan
xLURKxDOGx
"An angel fat, at satan's feast"
It's a 273 from a 1967 satellite. It has the stock heads # 2758920 which are close chambered, gasket matched with new valves/guides and springs with an offenhauser 4 barrel manifold, not 100% on carb choice yet. I wasn't planning on playing with the rear end just yet but I haven't written it off completely. I'm wanting to go with headers but that might be a tall order on that body, it seams that my best bet will be having them made but that's going to be costly.
Jake
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Don't forget the power band for those cams are based on 340/360 engines in a 273 there gonna act like a cam with 10-15 degrees (advertised) higher. Probably add 600-1000 rpm to those numbers.
Probably you wouldn't want to higher than 255-265 range
unless your willing to go with stall and gears
Probably you wouldn't want to higher than 255-265 range
unless your willing to go with stall and gears
roccodart440
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3:23's are going to make whatever convertor you have act like a little more convertor than it is. I would guess the stock stall speed is around 1800 and the stock ones are tight. I'd call and have one made. Buying an off the shelf unit is iffy and if you buy the TCI's or B&M's they are just crap. I would think a 2500-2800 would be ideal for you. Don't be afraid if they recommend more.
The MPP .509 cam is a hyd flat tappet. I don't get why you think .500 is the cut off. There are hydraulics out there well over .500 lift.
again guys and this is getting really old.
1. You can't compare cams using advertised duration. Not ever, Not never. Repeat..
Not necessarily true if you know what lift the advertised duration are measure at you can use advertised duration to compare cams. But both should be looked at to get some idea the shape of the ramps. Plus all specs of the cam should be scrutinize in making the decision to with which one to use. Cause you could have 2 cams with say 230 @ .050" and be very different from each other.
If everybody used the same standard for measurement, advertised duration would be the best comparison. But since some measure at zero, some at .002", .006" .010" and even up to .020" in some cases, advertised duration numbers are just a guess at best.
In order to make the best choice, you need to look at all camshaft specs. Every singe one.
Honestly as usual, this has been made much more complex than the OP needs, and all in the name of trying to show each other how smart we are.
To the OP, all you need to do is choose a cam with around .460-.480 lift, no more than 230* duration @ .050" ground on a 112 LSA. I would shoot for around 220 @ .050 on a 112. Keep the intake closing event under 60* ATDC for good cylinder pressure. Keep overlap low. Under 30* if possible. This will give a nice broad torque curve, nice street manners and a strong vacuum signal for a clean idle and strong bottom end torque.
Stick to those simple rules and you will not miss. It does not matter which brand you choose. IMO, I would go with a solid cam using those above specs as a guide. The solid cam will produce a little more torque all things being equal, but even then will be splitting hairs.
Really, all these out of the woodwork experts ain't necessary. This ain't rocket science, no matter how many of yall want to make it out to be.
In order to make the best choice, you need to look at all camshaft specs. Every singe one.
Honestly as usual, this has been made much more complex than the OP needs, and all in the name of trying to show each other how smart we are.
To the OP, all you need to do is choose a cam with around .460-.480 lift, no more than 230* duration @ .050" ground on a 112 LSA. I would shoot for around 220 @ .050 on a 112. Keep the intake closing event under 60* ATDC for good cylinder pressure. Keep overlap low. Under 30* if possible. This will give a nice broad torque curve, nice street manners and a strong vacuum signal for a clean idle and strong bottom end torque.
Stick to those simple rules and you will not miss. It does not matter which brand you choose. IMO, I would go with a solid cam using those above specs as a guide. The solid cam will produce a little more torque all things being equal, but even then will be splitting hairs.
Really, all these out of the woodwork experts ain't necessary. This ain't rocket science, no matter how many of yall want to make it out to be.
roccodart440
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Since you echoed, mirrored and agreed with everything I've said. I'm assuming you and I are the only experts that aren't out of the woodwork? But wait, i'm not an expert, lol.
Hipo65
Yeah I'm "That Guy"
Another vote for the isky E-4 here! I've got 1.6 crane iron rockers on top of it & shounds just like TMM's 273. Pulls hard from 2500 to 5300 then barks rubber into next gear! Also with the lower comp piston will be less CR & may hurt tq a little but will allmost certinly give a little bit (i mean little) choppyer idle. I also used the comp cams direct lube solid lifters & there the same cup hight as a hyd lifter soooo shorter push rods are a must.
Me either. I never claimed to be. I am merely echoing what I have read and learned through trial and error and real experience. You're more the expert than you might want to admit, though.
Even my own explanation is to "expert sounding" and complicates it up way too much. It's hard not to get too complicated, because I want to make sure to help someone make the best choice, as it seems so do you. I mean, some information you simply cannot leave out or cut corners on.
If it was as easy as "Just put cam X in it" that would be fine. But it's not, because then you have a hundred different people asking "why not this one?" so you have to explain why you made the recommendation.
That's why I just stopped making specific recommendations and give general guidelines. I'm far from an expert. I am quite the opposite. I try to approach a subject as if I know nothing about it. That way I keep my mind more open to learning new ways. I parrot some stuff as we all do, but I do have a long career of turning wrenches to pull real world experienced information from as well. Most of that experience is repairing things I tore up. LOL
roccodart440
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I was just busting your *** rusty. The thing that drives me nuts is actually the basic stuff people misunderstand or neglect.
Perfect examples are when people talk about cams using advertised duration. My cam is advertised at 284. Crane makes one with the same spec @.050 but their advertised is 320. I know why, but this is why I try to tell people you can't and should never compare cams using advertised durations. Now you get into guys like IQ52 that begin looking at duration at .010, .015, .020 etc and now you're into a hole other realm of ramp angles etc.
Lift, guys that say a cam is more radical because of lift.. (yet has less duration thna cam with less lift) perfect example. MPP 284/.528 vs. 292/.509 cams.
Last is timing. One of the first tings i''l ask a guy to see what he knows is what is your base timing, whats the total and when is it all in by? 90% or more... Deer in the F'ing headlights glazed stare. at which point i'm out. (or in a race MAYBE I'M IN!)
Perfect examples are when people talk about cams using advertised duration. My cam is advertised at 284. Crane makes one with the same spec @.050 but their advertised is 320. I know why, but this is why I try to tell people you can't and should never compare cams using advertised durations. Now you get into guys like IQ52 that begin looking at duration at .010, .015, .020 etc and now you're into a hole other realm of ramp angles etc.
Lift, guys that say a cam is more radical because of lift.. (yet has less duration thna cam with less lift) perfect example. MPP 284/.528 vs. 292/.509 cams.
Last is timing. One of the first tings i''l ask a guy to see what he knows is what is your base timing, whats the total and when is it all in by? 90% or more... Deer in the F'ing headlights glazed stare. at which point i'm out. (or in a race MAYBE I'M IN!)
Yup. We've all been there at one point, but the thing is to listen and learn. I just don't think there are some people with the ability.
And IQ52 was born knowin everything already. lol
Sorry I blew up!
xLURKxDOGx
"An angel fat, at satan's feast"
Thanks for all the input guys!! I'm more than likely going to stick with this and see how she works out, I'm ways away from finishing her but it's possible the more I poke around on the subject I'll change my mind. On a lighter note; I got my intake and valve covers back from the powder coasters and they look superb!!
Jake
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Jake
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Looks great Jake. Let us know how she runs. tmm
mph
Well-Known Member
Looking good!
Im expecting my 273 soon. Its only just finished being built and about to be shipped to OZ.
Im expecting my 273 soon. Its only just finished being built and about to be shipped to OZ.
xLURKxDOGx
"An angel fat, at satan's feast"
xLURKxDOGx
"An angel fat, at satan's feast"
I will, I'm slowly picking away at it. It seems my last /6 build went way faster but then again I had a complete engine but this had a bunch of missing parts, it's been fun hitting the junkyards looking for elusive parts.
Jake
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mph
Well-Known Member
You are right, hopefully worth it though... 470hp at 8500rpm.
I will start a new thread when it arrives.
I'd love to have the access to parts like you guys. Looking forward to seeing what you do with it.
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