What have I done?? Good, OK, or Bad??

[racprops]

Thanks again for much help and effort.

So it is not a lot..funny as some have claimed 20/40HP....

I run the Rhoads timing as two cams, one with the stock cam and the other with the 10% reducted duration and lift.

And then combine them. My understanding is they will pump up around 3k and thus be running the stock profile.

So I came up with this as a composite.

Rich

 

[Indycars]

Thanks again for much help and effort.

You're welcome, glad I could be of some help !

I run the Rhoads timing as two cams, one with the stock cam and the other with the 10% reducted duration and lift.

And then combine them. My understanding is they will pump up around 3k and thus be running the stock profile.

So I came up with this as a composite.

That seems to be as good approach as any.

 

[racprops]

OK I felt there was something wrong....I thought I made a mistake somewhere.

And I found it, I was changing the duration and lift BUT not the Seat to Seat duration.

So correcting that error gave me these results:

So that is it. I think...darn I need to recheck the Rhoads with a 1.6 rocker and 4 degrees retarded...

 

[racprops]

Rechecked the Rhoads with a 1.6 rocker and 4 degrees retarded...

Lost torque and HP.

Still best as built:

Rich

 

[Grumpy]

http://www.pbm-erson.com/UserFiles/Documents/CamCards/119811.pdf

rick, what would the results be if you went with this mild roller and the 1.6:1 rockers

 

[Indycars]

Here you go .....


.

 

[Grumpy]

thank you! I was curious how a generalized mild generic cam would graph out!

 

[racprops]

I would like to check it with DYNO2006 but I need a few different numbers.

Rich

 

[racprops]

Here you go .....

View attachment 16665
.

Am I reading this right, my Oregon cam is stronger from 1K to 4.5K??

And yours shows higher numbers than I get with DYNO2003...I get 385 at 2000 and yours shows about 420 and even goes higher at about 2200.

Yours show a HP peak at 3400 of about 240, where I get 214 at 3500, and a 5K about 170HP and I get 142.

Wish we got the same numbers, It worries me. I LIKE your numbers better.

Rich

 

[racprops]

OK I was concerned until I remembered yours does not include the effect of the 10% reduction below 3K by the Rhoads Lifters.

Rich

 

[Indycars]

thank you! I was curious how a generalized mild generic cam would graph out!

You're welcome!

 

[Indycars]

I would like to check it with DYNO2006 but I need a few different numbers.

What numbers do you not have ???

 

[racprops]

This is the cam set up for DYNO2003:

Things like seat to seat.

 

[Indycars]

I thought you had seat-to-seat timing numbers. Are you referring to after the Rhoades lifter reduction ?

BTW, you have been saying there is a 10% reduction which equates to 20.6°, but the Rhoades website says a reduction of 5° - 15° period. Did I miss something or get the wrong info ?

 

[racprops]

I talked with the son of Mr. Rhroads personally, and HE said pick any feeler gauge between .05 to .025 and set them by it.

In my case we worked out that a .010 feeler gauge would give me what I wanted and have a very mild clicking noise.

It is clearly stated in the above copy.

Rich

 

[Indycars]

It is clearly stated in the above copy.

Sorry, I don't see where it says 10%.

 

[racprops]

They don't per say:
But it is there and I checked with Mr. Rhoads personally.

I see your not just talking about lift only that was clear .010 gauge = 10% reduction in lift, but DURATION...I may have gotten that part wrong...there is not a clear word on how that will work or be.

Called but no answer, will try later.

So damn many fractures to know and figure and input...

Rich

 

[Grumpy]

Ive used Rhroads lifters for 5 decades, mostly the flat tappet design
(yeah, I like them and had no problems)
(but, yes Ive used a few of the hydraulic roller versions too)
(what I used on the 1985 vette) (along with 1.6:1 erson roller rockers, and a rocker stud girdle)
I just tighten the rocker at idle until the clicking stops, then slowly back off the rocker until,
you barely hear the clicking at idle and lock the jam nuts down,
I've never had any issues, with function or durability.

 

[racprops]

Good to know, but I wanted a certain effect, a certain change I want to detune my cam to a similur power curves like the stock cam in a 1990 Caddie's SBC350.

I matched the cam with 10% reduction to that Caddie Cam. I matched the cam and lifters.

 

[racprops]

Time and Time again I read and was told that you cannot gear a stock engine to run at 1500RPMs as it will lug.

And time and time I read BUT IF the engines torque peak is AT 1500RPMs of very close you can do it.

One of my bibles is: "Trailer Life's: RX for RV performance &Mileage" By John Geraghty and Bill Estes pup. 1983.

They dealt with tuning an engine for just the thing I want to do, cruse a RV at speed and perhaps tow. They covered the subject very well from engine to transmission to rear end gearing.

It was my guild book.

Rich