Turbo Dodge Forums banner

Status
Not open for further replies.
1 - 20 of 45 Posts

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #1 (Edited)
Use this link to run the cam card numbers here!

Cam Card Finder

E-27829 this is the old cam number that has a proven track record.

F-5365 this is the cam set in knightmoves.
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #2
please share the wealth!! lots of cards and what each of us have experenced from the cams will help with the R&D of our engines!!:thumb:
 

·
Premium Member
Joined
·
872 Posts
DO you have SOHC or DOHC in your car. The second # shows DOHC but the info don't seem to mach I think, maybe I am wrong.
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #4
DO you have SOHC or DOHC in your car. The second # shows DOHC but the info don't seem to mach I think, maybe I am wrong.
i have a SOHC when i had my cam's reground they posted it on a DOHC for some reason. the only spec that is wrong is the rocker. ours are about 1.6:1 so all you have to do is take the lobe lift which is .270 i think and multiply it by 1.6 and that is the lift! that should be .432 lift! the duration is as listed in the card.
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #6
i want to remind every one that if they are using the solid rockers they are 1.5:1 rockers so do the math before you order!
 

·
Premium Member
Joined
·
2,528 Posts
A couple questions:

Has anybody defined the minimum amount that needs to be removed from the base circle to run the solid lifters?

Do we need to have them to change the cam grind (ramp rate and lobe positions) to be truely compatible with solid rockers? (The roller hits the cam at a different spot on the cam with the solid and hydraulic. I haven't spent the time to figure out the net effect to the engine. )


I think the mild regrind I am currently running is holding the engine back at higher RPM. So I am contemplating what grind I want and if I should go to solid lifters.
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #8
A couple questions:

Has anybody defined the minimum amount that needs to be removed from the base circle to run the solid lifters?

Do we need to have them to change the cam grind (ramp rate and lobe positions) to be truely compatible with solid rockers? (The roller hits the cam at a different spot on the cam with the solid and hydraulic. I haven't spent the time to figure out the net effect to the engine. )


I think the mild regrind I am currently running is holding the engine back at higher RPM. So I am contemplating what grind I want and if I should go to solid lifters.
i looked at a couple of posts because i thought that Brent had said something about the real size of the base circle. right now my valve lift was cut to a .270 at the lobe. so i think that would be pretty small compared to stock. with an 1.5:1 rocker (the solid) i have a lift of .409. if you use the hydraulic rocker it is .439 lift!! Brent did say that a stock cam has too big of a base circle to run the solid rockers.
 

·
Registered
Joined
·
947 Posts
IIRC the solid adjuster was as low as I could have it with the stock valve. Using the G54B it was holding the valve open. It would be a good idea to remove material off the base circle. It gives the adjuster more room to work with and will bring the geometry closer to stock. None of us have that magic number that needs to be taken off but I think it's safe to say we can run pretty much any regrind we want to provided we move to solid lifters.

That being said, my cams are still at Crower and I'll post my cam card once they're done. Sadly my regrind will only be useful for someone who performs roughly the same head modifications...BUT, maybe if my head turns out great more will follow :fingersx:
 

·
Premium Member
Joined
·
2,528 Posts
Over lunch I did some analysis of the impact of switching to the solid lifters.

For the front cam,
the intake lobes will be advanced.
the exhaust lobes will be retarded.
increased overlap.

For the rear cam,
the intake lobes will be retarded.
the exhaust lobes will be advanced.
decreased overlap.

I will have to take some more measurements to figure out how much.

Also note that because of the reduced ratio, duration at .050" will be reduced. How much will be determined by the ramp of the cam.
 

·
Registered
Joined
·
577 Posts
The rocker ratio can not effect duration, duration is made into the cam and can only be changed by regrinding the cam. and you dont even measure duration using any rocker ratio numbers. Rocker ratio can only effect the amount valve lift made. Now if the rocker is not keeping contact with the lobe that is a totally different can of worms.
 

·
Premium Member
Joined
·
2,528 Posts
The rocker ratio can not effect duration, duration is made into the cam and can only be changed by regrinding the cam. and you dont even measure duration using any rocker ratio numbers. Rocker ratio can only effect the amount valve lift made. Now if the rocker is not keeping contact with the lobe that is a totally different can of worms.
Then please explain the duration @ 0.050". What does the 0.050" refer to? Never seen anything that implies that is anything other than .050" valve lift. If the ratio changes, then the point of .050" valve lift changes and thus duration (angle) at that lift or higher will changes.
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #13
Then please explain the duration @ 0.050". What does the 0.050" refer to? Never seen anything that implies that is anything other than .050" valve lift. If the ratio changes, then the point of .050" valve lift changes and thus duration (angle) at that lift or higher will changes.
duration at .050 is an industry standard. they start to measure how long a valve is off the seat starting at .050. then how ever many degrees it takes to reach .050 on the other side of the lobe is the duration of the cam. some cam makers try to use advertised duration which starts at .020. but most every engine builder i know wants to see the duration at .050. mainly because air flow is so minimal at .020 no one wants to use it because duration is directly linked to power estimates. so taking the measurement at .020 is just to make the cam look bigger than it is! the ramp of the lobe is another factor. a steep ramp will make the valve reach full lift quicker but, will make for a noisily motor because the ramp slams the door (valve) shut pretty hard! so most of the time only heard core racers use a steep ramp. the ramp is also the reason they want to make the measurement at .050. because it will help tell just how steep the ramp is.
 

·
Registered
Joined
·
5,784 Posts
duration at .050 is an industry standard. they start to measure how long a valve is off the seat starting at .050. then how ever many degrees it takes to reach .050 on the other side of the lobe is the duration of the cam. some cam makers try to use advertised duration which starts at .020. but most every engine builder i know wants to see the duration at .050. mainly because air flow is so minimal at .020 no one wants to use it because duration is directly linked to power estimates. so taking the measurement at .020 is just to make the cam look bigger than it is! the ramp of the lobe is another factor. a steep ramp will make the valve reach full lift quicker but, will make for a noisily motor because the ramp slams the door (valve) shut pretty hard! so most of the time only heard core racers use a steep ramp. the ramp is also the reason they want to make the measurement at .050. because it will help tell just how steep the ramp is.
Using this train of thought and logic it seems to me the solution would be to design an assymetrical lobe! Have it be steep on the opening side and then ease the valve back down. You would get more duration AND the lift that way. I wonder if this has been/is employed?
 

·
Premium Member
Joined
·
2,528 Posts
Using this train of thought and logic it seems to me the solution would be to design an assymetrical lobe! Have it be steep on the opening side and then ease the valve back down. You would get more duration AND the lift that way. I wonder if this has been/is employed?
Yes such things have/are being done. For SBC and SBF type engines there has been a lot of development into the cam profile. How do you lift the valve as fast as possible without throwing it (unless that is what you intend, and yes there are some cams designed to do that when "lift" is rules limited.)

Then on the ramp down you want to do it is quickly as possible (so you have more time at high lift), but still sit the valve down on the seats "gently" so that the valve doesn't bounce or tulip.

Problem is you need to run a profile on a spintron with the spec'd springs to truely test the effectiveness of the profile. ie. no bounce, springs control the valve, etc...
 

·
Registered
Joined
·
5,784 Posts
What I don't get is why spintrons are so darned expensive. It seems to me a poor man could build one fairly easily with an industrial AC electric motor and a speed control. Use an adjustable strobe light that you can tune to the rpm the valvetrain is spinning at...ta-da!! Poor man's spin-tron!
 

·
Registered
Joined
·
2,242 Posts
WE need some layman information each cam profile so people can better understand each cam.

Also, is there a cam card for a cam specifically setup for using the solid rockers?
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #18
WE need some layman information each cam profile so people can better understand each cam.

Also, is there a cam card for a cam specifically setup for using the solid rockers?
not yet. the thing you have to remember about a solid rocker on a cam is that when you move from a hydraulic to a solid the cam will act bigger than is was. the reason is the solid does not "give" like the hydraulic does. so the lift it more true with a solid than a hydraulic.so if a hydraulic has a cam at lets say .395 lift. after the compression of the lash adjuster the valve may only see about .375 to .380. a solid wont do that!! if the lift is .495 that is what you'll get!!
 

·
Registered
Joined
·
5,784 Posts
Technically speaking there really should be NO differenced between how a hydraulic cam and a solid cam actuate the valve! (keeping in mind I'm throwing out the rocker ratio here for simplified explination)

Liquid is incompressible, for our purposes. That means that as long as your oiling system is working correctly, and you do not have aerated oil, that the hydraulic lash adjusters act just like a solid one. The difference is that the hydraulic adjuster automatically takes up the slack between the rocker and the cam caused by the expansion of the valve when it gets hot. This is the reason you have to set, and adjust valve lash with solid adjusters.

Now, the reason we are interested in using solid adjusters is that our stock hydraulic units are prone to failure where they "leak down". This means they don't hold the oil pressure they should and allow the rocker to compress the adjuster somewhat before i actuates the valve. This is a bad thing. It makes noise and costs performance and economy. Some people also have an issue with oil aeration where they are either spinning the engine up in higher rpm, or taking corners hard where they introduce some air into the oil. Air is compressible, and the same issues occure. So, in order to bypass these problems, solid adjusters are preffered. The compromise is that you loose a little rocker ratio and you have to make periodic lash adjustments so that the valves are actuated at the correct time and the correct amount.

HTH! :thumb:
 

·
Premium Member
Joined
·
5,905 Posts
Discussion Starter #20
Technically speaking there really should be NO differenced between how a hydraulic cam and a solid cam actuate the valve! (keeping in mind I'm throwing out the rocker ratio here for simplified explination)

Liquid is incompressible, for our purposes. That means that as long as your oiling system is working correctly, and you do not have aerated oil, that the hydraulic lash adjusters act just like a solid one. The difference is that the hydraulic adjuster automatically takes up the slack between the rocker and the cam caused by the expansion of the valve when it gets hot. This is the reason you have to set, and adjust valve lash with solid adjusters.

Now, the reason we are interested in using solid adjusters is that our stock hydraulic units are prone to failure where they "leak down". This means they don't hold the oil pressure they should and allow the rocker to compress the adjuster somewhat before i actuates the valve. This is a bad thing. It makes noise and costs performance and economy. Some people also have an issue with oil aeration where they are either spinning the engine up in higher rpm, or taking corners hard where they introduce some air into the oil. Air is compressible, and the same issues occure. So, in order to bypass these problems, solid adjusters are preffered. The compromise is that you loose a little rocker ratio and you have to make periodic lash adjustments so that the valves are actuated at the correct time and the correct amount.

HTH! :thumb:
i am just passing on what crower cams passed on to me when i had them regrind my cams. and there words were that a hydraulic lifter looses lift and a solid does not. :shrug:
 
1 - 20 of 45 Posts
Status
Not open for further replies.
Top