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  #1  
Old 10-08-2002, 01:25 PM
jlcoffell jlcoffell is offline
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Question Cam Centerline Question/Opinion

Looking for some ideas/help/opinions.

I am installing a mopar performance cam, the reproduction performance cam with the split duration p/n p4452783, in a 440.
The label on the box say centerline is 115 degrees. paperwork inside says 113 degrees.
Does anybody out there know what it should be?
I checked my install and found that it was at 112.5 degree's when
using no offset bushings and at 0 degrees. note: I have a timing
set that allows 4 degrees advanced 0 degrees and 4 degrees retard.
Does this little bit matter ? .5 degrees if it is 13 and 2.5 degrees at 15.
Don't know if this makes any difference but here is the set up.

1969 440 11-1 comp, edelbrock performer intake, carter TQ,
A727 w/shift improver kit, 3.92 gears, np205 transfer case (4x4)

running gear is in a 1974 dodge adventurer sport 4X4 1/2 ton.

Is used mostly for sitting at stoplights waiting to go. Okay actually
is used for hauling motorcycles (dirt bikes), misc stuff from the local home improvement store, top soil, bark, all the good stuff that goes around the house you wouldn't want to put in a car.

Any help/ideas greatly appreciated.
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  #2  
Old 10-08-2002, 02:39 PM
451Mopar 451Mopar is offline
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I think the 115 degrees is the Lobe seperation angle or lobe centerline. The 113 might be the installed centerline in relation to the crank position.
If the recommended installed centerline is 113 and you have 112.5 your set!
This should be good with your 11:1 compression. Actually that is alot of compression for such a mild cam, is this supposed to run on pump gas?
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  #3  
Old 10-08-2002, 02:55 PM
jlcoffell jlcoffell is offline
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:shock: long Story

This could be a long story but a short blip is: yes I want it to run on pump gas. I just removed an engle s324 cam (2000 rpm up) and basically trying to tone down the motor. The pistons are actually trw 11.1 to 1 forged and .060 over. I don't want to take
apart the lower end as rods are .020 under etc. I changed from 516 heads to the larger cc 906 heads hoping this will decrease overall comp slightly. With the large engle cam,comp, etc I was running an edelbrock torker w/holley manual, 780 double pump.
using octane booster and in a 69 road runner w/4 speed, the car
went really well. I now want it to be a mild truck motor as it only has 25k miles. In the truck even with the 3000 stall TC it did not run correctly. I want to install a stock torque convertor and use it as a utility truck and of course have the ability to accelerate hard if I want to.
The cam issue though is that i have heard that 1 degree either way won't make a difference. Is this crank degrees or cam degrees?
I simply just don't know enough to be able to determine if the engine will perform better if I retard the cam 1 degree or leave it as is.
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  #4  
Old 10-08-2002, 03:24 PM
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polarapete polarapete is offline
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Thumbs up Leave the Cam Timing as is....

You don't want to retard the cam - that moves the power band higher not lower where you want it.

You are doing very much the same thing as what I did to my 440. I have a .030 over 440 with the Speed Pro #L2355F 10.5 to one pistons. These pistons are flat tops with four valve releifs. I beleive that what you have are the same. I had a MP 284 X .484 cam in the motor first. It sounded ferocious, but, was a dog. No low end, but, great over 70 mph. Too much compression, had to use octane booster in every tank of 92 and it still rattled under a light load.

I took off the "346" heads and replaced them with "452" heads that have 2.14 x 1.81 Stainless valves. I then had the chambers flycut to unshroud the valves and did some minor cleanup that got my chambers to about 90cc. With the thick FelPro gasket my calculated compression is about 9.3 to one. I then installed the RR repro cam that you have and degreed it at the 2 degree advance as specified. Now the motor is much more civilized and it runs on straight 92, no more octane booster. I am still working with the Edelbrock #1407 750 Cfm carb jetting and the ignition curve to get it just right.
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Old 10-08-2002, 03:53 PM
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dirty dan dirty dan is offline
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Thumbs up cam degree

That should be some kind of truck engine!
All the info already posted is of very good quality and accuracy.
112.5 will do fine for what you want.
Your fuel will have to be a min:92 octain.
However you should be able to haul all the yard supplies and your
motorcycles at the same time.
The 115 lobe centers will give you a wide power band.
And make it easy to drive.
The intake you mentioned is an exalent choice.
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  #6  
Old 10-08-2002, 08:31 PM
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rumblefish360 rumblefish360 is offline
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Just a side note/question.

For snall blocks, MoPar has a .060 steel shim. Do they have this for big blocks?
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Old 10-09-2002, 11:13 AM
jlcoffell jlcoffell is offline
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Default Rumblefish 360

For the big blocks they do not use shims. You use what they
call offset bushings. The cams mount by a single bolt (unless a six pac set up) and then an alignment pin to the cam.
What you do is to drill the alignment hole larger in the cam sprocket so the offset bushing will fit in. The bushings come in kits with different degrees of offset typically like 2, 4, 6 etc.
I don't remenber all the sizes but I did order a mopar performance offset bushing kit. Guess I don't really need it now.
Also I did ask about offset keys for the crank and they don't recomend that you use that method as it throws off the balancer.

To everyone that replied thanks alot. This helped me feel better
about leaving it at 112.5 degrees.
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  #8  
Old 10-09-2002, 12:12 PM
Mopar_Maniac Mopar_Maniac is offline
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I believe rumblefish was talking about the .060 spacers for lowering compression.

The answer is yes, they are made for the big block. Part number P4529099 it comes as a set of two. These will drop the compression ratio of a big block appx 1 full point.

The shim is install next to the engine block, then install the head gasket on top of the shim. Chrysler recommends that a gasket sealer be used on the shim.
Because of the increased installed height of the heads you will have to use multiple gaskets on the intake manifold. Add .074" of gasket thickness to the standard intake thickness, usually about .030", total thickness should be appx. .104" plus allow a little extra for gasket "crush."


Mopar_Maniac
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  #9  
Old 10-09-2002, 03:08 PM
jlcoffell jlcoffell is offline
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Default UUUGGGHHH

Okay I guess thats what I get for trying to answer before
having my morning quota of caffeine.
I wish I had known about those spacers prior to putting this thing
back together. I think I would have used them.
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  #10  
Old 10-10-2002, 01:34 PM
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rumblefish360 rumblefish360 is offline
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Yep, thats what I'm talkin about. Head shim.
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  #11  
Old 10-10-2002, 04:17 PM
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dirty dan dirty dan is offline
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Default intake gasket

I belive it was Mr gasket that makes an exta thick paper type
intake gasket that would probably make up the differance.
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