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544 Vs Re13
https://www.ausmini.com/forums/viewtopic.php?f=2&t=47190		 Page 1 of 1
Author:  Bubbacluby [ Sat Nov 01, 2008 10:28 pm ]
Post subject:  544 Vs Re13
While there are many happenings on the cam shaft in various questions and posts, i wanted to know, how does the old school 544 camshaft compare to the RE13 ?

I wanted to go with a period camshaft rather than a newey and it to have a lumpy idle. not i will be staying with 1 1/4 su's

Mate has a 731 in his GT and another mate has a 544 in his S with twin
1 1/4's, i have been in my mates 731 GT, and thought i would like something a bit wilder and bigger.

Advice please

Thanks Brenton
Author:  drmini in aust [ Sun Nov 02, 2008 5:58 am ]
Post subject: 
The 544 was a race cam back in the 60s, it was used in Formula Junior.
I ran one in a 1220 (bored out 1098) roady motor back then, with twin Amal Monobloc carbs and a worked 1275 head it used to do 16s down the 1/4 mile on Olympic GT radials. :lol:
It revved to 8500 until a circlip broke, the #3 bore got gouged and the NEW crank had 8 cracks in too, by 20,000 miles. :cry:

I would take an RE13 these days for drivability, if it's a road car.......
also you may find it hard to get an accurate 544 repro grind.
Author:  TheMiniMan [ Sun Nov 02, 2008 1:02 pm ]
Post subject: 
They`re both lumpy-ish on idle,,, however the RE13 is far more drive-able on slight throttle,,, the 544 is a rough old rally thing
Author:  Bubbacluby [ Mon Nov 03, 2008 8:28 am ]
Post subject: 
Thanks Matt and the Doc

Is the RE13 a modern version of the 544, or the 544 was bigger ??
what is the rev range comparison?

Sort of like the 266 is a modern version of the 731

Thanks Brenton
Author:  drmini in aust [ Mon Nov 03, 2008 11:29 am ]
Post subject: 
The 544 has a bit more duration than an RE13 but that's not all that matters in cam design.
RE13 was designed knowing what works to give midrange and top end power, for street use.
However my 1310 still revved past 8000, after I changed the worn-out VP3 cam for an RE13.

If you want a real RACE cam Graham can oblige, but they are pigs on the street. They don't last long, either. :lol:
Author:  Bubbacluby [ Mon Nov 03, 2008 5:18 pm ]
Post subject: 
Thanks doc

Can you please explain to me what "duration" actually means??
Does these mean both valves (inlet and outlet) are open for longer??

Also why do the rally race cams not last very long
Author:  TheMiniMan [ Mon Nov 03, 2008 5:33 pm ]
Post subject: 
"Duration" is how long a particular valve is effectively open for,,,, can be different for inlet & exhaust on the same cam ,,, depending on the cam.......

the "over lap" is how long both the inlet & exhaust are open "together" for, which is then governed but both the duration & the lobe centre angle

this can become a can of worms when describing how cams work & the differences between them,,, you may want to buy a few books if you`re keen to learn

sorry to butt in on your question to Doc Kev, I just thought i`d throw in the inevitable spanner :-)
Author:  drmini in aust [ Mon Nov 03, 2008 6:07 pm ]
Post subject: 
Thanks Matt.
The reason GOOD race cams don't generally last long (ie they need freshening up on the cam grinder regularly) is they push the limits possible for valve acceleration and lift.
Some currently popular UK short duration road cams are doing this trick too, because it works to make power. They have been found to wear quickly, particularly if 1.5:1 rockers are used on them.

If buying a reground or aftermarket cam, pay attention to the radius over the cam nose. The bigger this within reason, the more durable (ie long lasting) the cam will be.
An RE13 has a nice big radius there. :D
<edit> The **3 cam in my old 1310 motor did not, and after 45,000 miles the valve lift (with 1.5:1 rockers) had dropped from .470" to .270" on a few of the lobes... so I binned it.
Author:  Bubbacluby [ Mon Nov 03, 2008 9:11 pm ]
Post subject: 
No Worries Matt i appreciate it.

Thanks again Doc.

i might do a bit more research on cams before deciding which one to go with. :lol:

Brenton
Author:  albino235 [ Mon Nov 03, 2008 9:26 pm ]
Post subject: 
Is there anything you can do to the cam to make it more durable with high lift cams? Like surface hardening?
I guess then you'd just be replacing the cam followers every 45000 miles instead?
Author:  drmini in aust [ Mon Nov 03, 2008 9:54 pm ]
Post subject: 
albino235 wrote:
Is there anything you can do to the cam to make it more durable with high lift cams? Like surface hardening?
I guess then you'd just be replacing the cam followers every 45000 miles instead?

Many race cams are now ground onto steel billets, not old std cams. The difficulty is getting them made at the right price in good material.
Author:  TheMiniMan [ Mon Nov 03, 2008 10:59 pm ]
Post subject: 
A lot of Hi-Lift , long duration, "Race" cams are made buy simply welding onto the lobes to make them bigger, then re-grinding to create the desired profile,,, & some that are done well do tend to last very long, but in saying that i have seen welded cams turn to sh!t within a few meetings too,,, Along with the followers,,,, There`s lots of factors to cause premature wear on cams,,, too many for me to list here, i`d be typing all night :-)

But the very best & longest lasting "Race" cam i ever had was a welded up one :-) still got it here too :-)
Author:  albino235 [ Mon Nov 03, 2008 11:09 pm ]
Post subject: 
Huh, who would of guessed you could wearface a cam...

Might give it a go myself with my next dud cam :lol: The doc was/is a welder isn't he maybe he could wearface all our cams :lol:
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