My Chevelle build and spot to Rant

[Strictly Attitude]

Question Grumpy and everyone else at what point of cam size dictate the need for shaft rockers? I obviously know shaft rockers are best but when does say a set of stainless stud rockers need a girdle? And when does the girdle no longer be a viable band aide?

I understand shaft mount is best at keeping geometry where it belongs as there is no swaying tower called a stud. But at what spring pressure or lift? Does rocker ratio effect this? Does pushrod length or diameter? What rpm does it really get hard to control? Is it just a matter of actual camshaft lift. Is there any rules I see guys running both successful but what keeps that success?

 

[Grumpy]

shaft rockers add rigidity , to the valve train,by eliminating the rocker stud flex issues,
but keep in mind that a rocker stud girdle can be added to the stock type of valve train,
and when used with quality roller rockers they add a good bit of rigidity to the stock style valve train.
short answer, as a rule of thumb,shaft rockers are advisable

(1) any time your valve open loads exceed 400 lbs and/or you want to exceed 6500 rpm regularly.
(2) any time you intend to exceed 7000 rpm regularly and valve open loads exceed 500 lbs they would be considered almost mandatory..
yes you can in most cases use a stud girdle, with quality roller rockers,
but the shaft rocker design tends to be more rigid, and tends to aid durability


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[Strictly Attitude]

Thank you Grumpy

 

[Strictly Attitude]

This was in my text messages from our friend Brian R.
Its a bit subjectivity when shaft rockers required .
Likely Seat Pressures 375-550 lbs.
Open pressures 500-1000 lbs
Shaft rockers an improvement on a bone stock engine.
Rocker arm travel arc is superior.
All Musclecar era Mopar engines used Shaft rockers.
All Early Oldsmobile V8 1953-1964.
Buick V8 used shaft rockers up to 1976 455.
Cadillac V8 used Shaft Rockers too
All Factory OEM Were Ductile Iron & Heat treated constructed.
Early Olds V8 aftermarket there were Thomson Magnesium shaft rocker arms.

The Videos Brian shared are good to watch I know scorpion has sets at just around $1000 stainless crowers are $1700 for shaft. I really like the idea of shaft rockers feel like added rigidity is well worth the money when you start to get on the rowdy side of valve trane.

 

[Strictly Attitude]

These seem like a good deal with out totally breaking the bank still doing my home work
https://www.summitracing.com/parts/...ing-products&gclid=CNXA2Lji8dMCFdaLswod7VkDCg

 

[Strictly Attitude]

My spring rates on my new heads are going to be 220-225 on the seat and 600 open and a 550 rate just some hints on what I got cooking. Titanium retainers will installed and my cam shaft is a billet core with cast gear.
I think I might have gone a little off the deep end

 

[Indycars]

That's OK John...... the deep end is a fun place to be !!!

 

[Strictly Attitude]

So I decided I will leak another clue on where my heads are coming from. I ordered them and the cam from the same place and the cam profiles are chosen out of master lobe catalog. I also had to put a deposit down on the parts and there is a lead time.

 

[Indycars]

I'm going to need more than that to make a guess! Are they sister companies or the exact same company?

 

[Strictly Attitude]

The master lobe catalog and the place I purchased it from are 2 different places. The place I purchased my Cam and Heads from is a fairly new business as they just recently went out on there own.

 

[Strictly Attitude]

So my camshaft came last week that was picked by Tony Mamo to work with my combo. I am normally a Isky fan when it comes to cams but this time I held my fate in anothers experience. I bought it as a set with my heads from Mamo Motor Sports. After I had sold my set of AFR 195 street heads. I went on a mission to buy a set of 210 AFR's found a set used on racing junk they were 75cc chamber and had the wrong springs on there for my application. Well turned out to be the old casting which has the A on the side. So that was a wash seeing they flow about the same as the 195's I just had. So I contacted Tony Mamo by email seeing that he would more then likely know the most about those heads. I am pretty sure he was part of the team that worked on the redevelopment of the AFR line and got his opinion. He pretty much let me know what I already knew so I sold them to a guy looking for heads on a supercharger application on a show car more concern with show then go. But either way I discussed porting options in my email and even worked over, it would be allot of money thrown into a head that can only deliver so much and a casting that is already really old. I decided to go with a set of his heads after we went back and forth a few times discussing what he could offer and for how much. It seemed like a good deal even though there was some wait time but I am ok with that if it is worth the wait any ways. So my MMS 215 heads are pretty close to being completed also. I cannot wait as I am closing in on the completion of this engine.

 

[Strictly Attitude]

Grumpy do you have any info into setting up or designing a 3 link rear suspension with a watts link

 

[Grumpy]

http://garage.grumpysperformance.com/index.php?threads/building-suspension-links.1755/#post-4427

https://www.miata.net/sport/Physics/

Physics of Racing Series

Part 1: Weight Transfer
Part 2: Keeping Your Tires Stuck to the Ground
Part 3: Basic Calculations
Part 4: There Is No Such Thing as Centrifugal Force
Part 5: Introduction to the Racing Line
Part 6: Speed and Horsepower
Part 7: The Traction Budget
Part 8: Simulating Car Dynamics with a Computer Program
Part 9: Straights
Part 10: Grip Angle
Part 11: Braking
Part 12: CyberCar, Every Racer's DWIM Car?
Part 13: Transients
Part 14: Why Smoothness?
Part 15: Bumps In The Road
Part 16: RARS, A Simple Racing Simulator
Part 17: "Slow-in, Fast-out!" or, Advanced Analysis of the Racing Line
Part 18: "Slow In, Fast Out!" or, Advanced Racing Line, Continued
Part 19 : Space, Time, and Rubber
Part 20 : Four-Point Statics
Part 21: The Magic Formula: Longitudinal Version
Part 22: The Magic Formula: Lateral Version
Part 23: Trail Braking
Part 24: Combination Slip
Part 25: Combination Grip
Part 26: The Driving Wheel, Chapter I

Physics of Racing Series, FAQ

 

[Strictly Attitude]

oh no forgot my tether down the hole I fall!!!!!!

 

[Strictly Attitude]

Some info for those who wonder a little bout suspension here is a taste

 

[Strictly Attitude]

So yesterday I found this can at my parents just sitting there so I was wondering what was in the can I found out it was full of worms. I grabbed what pics I could but allot missing as it got darker it made near impossible to get good photos. I got the vinyl top off as I noticed it was bubbling underneath. I noticed it a couple years ago starting. my suggestion at first sign rip that top off. More to come in a few making the little guy dinner!!

 

[Strictly Attitude]

I starting stripping the area of paint rust and glue. This is half done I did not get a good shot of the whole roof done at this stage.

 

[Strictly Attitude]

So I made a patch piece after cutting out the large hole and welded the other two holes up. You can see some of the original lime green paint from factory. The red paint it was in when my dad got it and the red paint I painted for him. Yes now the car will be stripped down too many layers for me. Amazing the difference of the thickness of the metal in a 1971 built car to today. If this was car today it would need all new sheet metal if I was rich and had more time on my hands it would get all new but I will neutralize the rust and skim coat instead.

 

[Strictly Attitude]

So to neutralize the rust this is all you need well a bucket and water also. You mix vinegar with water 3:1, 3 parts water 1 part vinegar in a bucket then use the scotch brite to spread it and work it into the metal in the pics you see it after it sat for about 10 minutes 10 to 30 minutes is good. After wipe clean with regular water and clean paper towels. If I was closer I would have hosed it off squeegeed it off the wiped dry. I started skim coating after this but ran out of time and light so covered all my work with rattle can primer. I need to order a gallon of evercoat rage extreme and a gallon of evercoat featherfill. Some guys like to epoxy the bare betal but this is not an option for me at this point. as I need to strip and do bodywork one panel at a time as garage is full of junk so no access.

 

[Strictly Attitude]

And also some engine porn for you guys as promised pics of the new MMS 215 heads.