Mopar Performance camshaft help

[Paul Secoy]

Hello all, I have a question; I am searching for a camshaft for my new build, and I have a Mopar Performance .528 solid thats been on the shelf for almost 30 years. It has many of the attributes I am looking for; it's a solid, the duration at .050" is in the range I am seeking, the lift is right in line with what I want, it has a wide lobe separation, (112*), so far, very good.. But... The overlap is listed as 60 degrees. I don't know a ton about cams, but apparently that is a crazy amount of overlap, and I am looking for minimal overlap with this build.

Even the stock Magnum cam is listed at 48 degrees overlap, still a ton, leading me to believe Mopar measures overlap at some other than normal point in the cycle, thus the huge numbers. Can anyone shed any light on this? My only other option at this point seems to be a custom grind.

Thanks in advance

 

[beanhead]

48° isn't a lot of overlap really...they are *likely* using the seat timing (advertised) duration. Overlap has to be calculated and some may use the intake open/exhaust close @.050 numbers, or the seat timing number. For example my hydraulic(275/[email protected] intake duration) uses the .050 timing numbers, which are on the actual cam card, and that adds up to only 15° overlap however the manufacturer's website shows the valve timing at the advertised (.006) duration which then calculates to 62° of overlap on 110 LSA. Your purple shaft .528 is the comparable grind in a solid to what I run. Mine is very streetable with just a bit of idle chop to know it's not stock. And that's on 110, your 112 LSA can seem even tamer depending on the tune and cubes of your engine. I personally really like that .528 cam in a street car. 60° of overlap is right in that "slightly hotter than stock" area and still gives decent vacuum. (I get 12-13" in gear in a 452-cube 9.5-1 compression engine). The lash on your solid is what makes that cam behave more like a 230° or so hydraulic in the lower range, but it kicks the hydraulic's butt up top!

 

[rumblefish360]

Yea, it’s a performance cam and that overlap is normal.
It’s not a big deal.
That cam is low 12 second capable in the right set up.

 

[Paul Secoy]

48° isn't a lot of overlap really...they are *likely* using the seat timing (advertised) duration. Overlap has to be calculated and some may use the intake open/exhaust close @.050 numbers, or the seat timing number. For example my hydraulic(275/[email protected] intake duration) uses the .050 timing numbers, which are on the actual cam card, and that adds up to only 15° overlap however the manufacturer's website shows the valve timing at the advertised (.006) duration which then calculates to 62° of overlap on 110 LSA. Your purple shaft .528 is the comparable grind in a solid to what I run. Mine is very streetable with just a bit of idle chop to know it's not stock. And that's on 110, your 112 LSA can seem even tamer depending on the tune and cubes of your engine. I personally really like that .528 cam in a street car. 60° of overlap is right in that "slightly hotter than stock" area and still gives decent vacuum. (I get 12-13" in gear in a 452-cube 9.5-1 compression engine). The lash on your solid is what makes that cam behave more like a 230° or so hydraulic in the lower range, but it kicks the hydraulic's butt up top!

Very good! I got to considering this cam after recalling a few articles outlining that a solid will behave like a hydraulic of 10 degrees LESS duration. This is a turbo build, (my first) and I have been informed that overlap is to be avoided. My budget on this build has long since come and gone, but if this cam will work, and work WELL, I'll use it, otherwise, it's time to cough up for a custom cam. Until I can muddle my way through the math, it sounds like I should have 15 degrees or less overlap. I'll check with my turbo mentors and see if its workable.

Thank you very much!

 

[beanhead]

Very good! I got to considering this cam after recalling a few articles outlining that a solid will behave like a hydraulic of 10 degrees LESS duration. This is a turbo build, (my first) and I have been informed that overlap is to be avoided. My budget on this build has ling since come and gone, but if this cam will work, and work WELL, I'll use it, otherwise, it's time to cough up for a custom cam. Until I can muddle my way through the math, it sounds like I should have 15 degrees or less overlap. Ill check with my turbo mentors and see if its workable.

Thank you very much!

Oooh turrrbo...sounds cool man! Whatcha building? 440? I have no idea how cam characteristics might affect a turbo build.

 

[rumblefish360]

This is not a turbo cam. It was designed as a N/A HP/Light Drag race cam.

 

[Paul Secoy]

Oooh turrrbo...sounds cool man! Whatcha building? 440? I have no idea how cam characteristics might affect a turbo build.

400 low deck. Steel crank, stock stroke, I left it this way as the fellows helping me said you don't really need the cubes, or stroke, and I figured the 3.38" stroke should be easier on the bottom end. Good rods/pistons, Edelbrock heads, M1 intake, blow through carb on E85. 75mm Borg Warner turbo. At this point, assuming I can nail down overlap on this cam, I will use the .528 MP solid. I have Harland Sharp rockers stashed in the same 25 year old pile I may as well use.

Not big on the cam is the normal recommendation, wide LSA, no more than about 230 degrees at .050", minimal overlap. Assuming the overlap proves to be in the range, the old MP 528 is looking pretty good. I found one thread online where a fellow used it in a very similar combo and loved it. I just like backing up claims with some real numbers I am looking for 750 to the wheels, which I am guessing to be about 900 crank. We shall see..

 

[beanhead]

I am looking for 750 to the wheels, which I am guessing to be about 900 crank.

 

[Paul Secoy]

The two guys helping me have some pretty serious cars. One is an injected LS twin turbo, makes about 1,500 Hp, the other is running a Mopar 6.4, single turbo, carb, cast iron exhaust manifolds and no intercooler and is making about 1,300 Hp, so I have some good wisdom on my side. The comparatively weak block I have is why I have to aim a bit lower.

 

[62 Dart Convertible]

I had the MP .528 in an otherwise stock 413 RB, and you could hardly tell it was anything other than stock.

14" vacuum and it took a discerning ear to detect a barely choppy idle.

PS - Do you have a post/thread on your turbo build? Sounds interesting!!

 

[BSB67]

View attachment 872928

Caption to this pic could be "....I'm building a 900 HP motor but know nothing about camshafts....."

 

[Paul Secoy]

Caption to this pic could be "....I'm building a 900 HP motor but know nothing about camshafts....."

I must assume you are the one who can answer my question? I'd appreciate it very much if you would grace me with your wisdom.

 

[BSB67]

I must assume you are the one who can answer my question?

Your question has been answered by others.

 

[Paul Secoy]

Your question has been answered by others.

Hmm, it would appear my ignorance of camshaft specs is only matched by my lack of reading comprehension, as I don't recall seeing it. I guess it has 60 degrees of overlap no matter where it is measured, silly me.

 

[BSB67]

Hmm, it would appear my ignorance of camshaft specs is only matched by my lack of reading comprehension, as I don't recall seeing it. I guess it has 60 degrees of overlap no matter where it is measured, silly me.

Please quote me your question that has not been answered.

 

[Paul Secoy]

Please quote me your question that has not been answered.

In post #2 beanhead states his cam, although listed as having 62 degrees overlap has only 15 degrees as measured at .050". This smaller number is what I am seeking, as it seems to be what is referenced most when I am looking for suitable cams. I have all the specs I can locate on the 528 cam, but the .050" numbers are not among them. I was hoping someone had information I cannot find to help me translate MPs overlap number to one I can better use for comparison. Thanks.

 

[BSB67]

The 60° for the 528 is from "advertised" numbers. This is the way all manufactures give overlap. I believe the 528 advertised is measured at 0.020". This is the same point that most cam suppliers, with some exceptions. Although my data is not here, and so I'd need to confirm this.

Overlap is derived from simple math. All you need is duration and lsa.

Again, I don't have my numbers here, but I believe that the 528 has 241°@ 0.050". You can do the math if you want overlap at the 0.050 duration for whatever that's worth.

That said, overlap and duration will change with lash. The recommended lash setting for that cam is pretty big like 0.028", so generally will operate like a cam with less duration and overlap than its advertised numbers might suggest.

Finally, you have the cam. You can measure everything you need and more.

 

[Curiousyellow71]

If you have a dial indicator and a degree wheel stick the cam and a lifter in a block with a crank and timing chain and check it. It is really the only way to know what you have other then sending it off an having it checked. The old mopar solids ran a lot of lash from as I recall....and I am not so sure about any of Mp's ratings anyhow. I've seen two different cams vary some that were supposed to be the same. And post the results.... Inquiring minds want to know. LOL

 

[Paul Secoy]

Thanks guys, the engine is apart and hopefully headed to the machine shop this week. I did find my degree kit while searching for the cam, I will see what I can find out when the block is back.

Yes, .028".030 lash, 241 degrees at .050".other than that all I have are the valves open close events.

 

[BSB67]

Thanks guys, the engine is apart and hopefully headed to the machine shop this week. I did find my degree kit while searching for the cam, I will see what I can find out when the block is back.

Yes, .028".030 lash, 241 degrees at .050".other than that all I have are the valves open close events.

Then you have everything you need to determine 0.050" if you want.