78-79 cams in an 84 USA engine???
03-25-2012, 01:53 PM
#1
Race Director
Thread Starter
78-79 cams in an 84 USA engine???
Since euro cams are hard to find and pricey, I've been looking at other factory 16V cam choices..... The 78-9 cams have identical lift to my 83-84 4.7L cams...but the early cams have 12' more intake duration and 13' more exhaust duration......
Does anyone have an engine analyzer program where they can enter the data to see what would happen? My engine runs great & makes good power, but clearly is a bottom end engine.....power really drops off at higher rpm....
my guess is the longer duration, wider centerline cams will have a bit less peak torque, but everything will shift higher in the powerband.....and probably have more peak HP....but I wonder if its worth it?
Does anyone have an engine analyzer program where they can enter the data to see what would happen? My engine runs great & makes good power, but clearly is a bottom end engine.....power really drops off at higher rpm....
my guess is the longer duration, wider centerline cams will have a bit less peak torque, but everything will shift higher in the powerband.....and probably have more peak HP....but I wonder if its worth it?
03-25-2012, 04:53 PM
#2
Nordschleife Master
If for some reason the heads or cams were off, hey, why not try the 78/79 cams, but I suspect its not worth doing with no other changes. Now if you took a "little" off the base circle ...
I'd get focused on the new car myself.
I'd get focused on the new car myself.
03-25-2012, 05:14 PM
#3
Race Director
Thread Starter
I'm just looking for a few more HP for the Estate.....
03-25-2012, 07:22 PM
#4
Nordschleife Master
You will get a couple more ponies with the 78/79 cams yes.
And a little more with a base circle grind.
Stock 16V fall after 5K from my experience. But I have had a chance to play with a 78/79
And a little more with a base circle grind.
Stock 16V fall after 5K from my experience. But I have had a chance to play with a 78/79
03-25-2012, 08:12 PM
#5
Former Vendor
Since euro cams are hard to find and pricey, I've been looking at other factory 16V cam choices..... The 78-9 cams have identical lift to my 83-84 4.7L cams...but the early cams have 12' more intake duration and 13' more exhaust duration......
Does anyone have an engine analyzer program where they can enter the data to see what would happen? My engine runs great & makes good power, but clearly is a bottom end engine.....power really drops off at higher rpm....
my guess is the longer duration, wider centerline cams will have a bit less peak torque, but everything will shift higher in the powerband.....and probably have more peak HP....but I wonder if its worth it?
Does anyone have an engine analyzer program where they can enter the data to see what would happen? My engine runs great & makes good power, but clearly is a bottom end engine.....power really drops off at higher rpm....
my guess is the longer duration, wider centerline cams will have a bit less peak torque, but everything will shift higher in the powerband.....and probably have more peak HP....but I wonder if its worth it?
Doesn't really seem to matter very much....it still seems pretty slow, to me.
I probably need to build him one of the 5.4 or 6.0 hybrids out of one of my new cranks....if they ever actually get done. Somedays, I think they must be making these things with a hand file....
Last edited by GregBBRD; 03-25-2012 at 10:12 PM.
03-25-2012, 08:20 PM
#6
Rennlist Member
you are not going to get much more brian. if you do a cam change, do the euros. Ill post what it did. also did the intake, so the results are a little loaded, but max torque didnt change a bit. (meaning your lower HP is still the same, so acceleration at the lower speeds is still the same 
) But i gained 35 more hp from 5000rpm to 6400rpm. sure the duration is a little better with the 78 cam, but the lift is really what you are needing.
why are you messing with the estate now that you have a stick racer that might be a little faster. I would bet that the new racer with the 4.5 will be very similar to the auto estate with the 4.7.
) But i gained 35 more hp from 5000rpm to 6400rpm. sure the duration is a little better with the 78 cam, but the lift is really what you are needing. why are you messing with the estate now that you have a stick racer that might be a little faster. I would bet that the new racer with the 4.5 will be very similar to the auto estate with the 4.7.
03-25-2012, 09:21 PM
#7
Race Director
Thread Starter
you are not going to get much more brian. if you do a cam change, do the euros. Ill post what it did. also did the intake, so the results are a little loaded, but max torque didnt change a bit. (meaning your lower HP is still the same, so acceleration at the lower speeds is still the same ) But i gained 35 more hp from 5000rpm to 6400rpm. sure the duration is a little better with the 78 cam, but the lift is really what you are needing.
why are you messing with the estate now that you have a stick racer that might be a little faster. I would bet that the new racer with the 4.5 will be very similar to the auto estate with the 4.7.
) But i gained 35 more hp from 5000rpm to 6400rpm. sure the duration is a little better with the 78 cam, but the lift is really what you are needing. why are you messing with the estate now that you have a stick racer that might be a little faster. I would bet that the new racer with the 4.5 will be very similar to the auto estate with the 4.7.
the new racer is lighter, has WAY better gearing and is more powerful....I will have hard data after the next race....it will be weighed and dyno tested + tuned...which is SUPER easy on the SDS system... my professional Butt-o-meter tells me the 5 speed is MUCH stronger....I'd say at least 250whp...
