Taking the 13B to 9000rpm
09-27-2006, 09:15 PM
#21
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Join Date: Jul 2003
Location: Barrie, Ontario, Cananda
Posts: 105
When rb recommends shimming the front reg they're referring to the fc reg. With the rew there is no need. I'm currently running a t2 block with the fd reg, and I just cut .125" off the spring for the front reg. It has the same effect as shimming it .125" which is what they recommend. I'm also running the mazda comp. jets in the eshaft and have no problems with low oil pressure. It helped my temps quite a bit. I see about 30psi at idle.
btw the fd reg is about 105psi.
btw the fd reg is about 105psi.
12-11-2006, 02:28 AM
#22
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Join Date: Oct 2003
Location: Fort Lewis Washington
Posts: 705
Originally Posted by cembrent' post='838783' date='Sep 27 2006, 10:15 PM
I just cut .125" off the spring for the front reg. It has the same effect as shimming it .125" which is what they recommend.
Maybe I misunderstood something here but how does cutting off a piece of the spring have the same effect as shimming. Shimming is used to add length not decrease.
Just my 2 euro cents.
12-13-2006, 04:17 AM
#23
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Join Date: Jul 2002
Location: DC
Posts: 875
It's the same concept as cutting your springs. adding the shim tightens up the front spring making it relieve later. While cutting it raises the spring rate and acomplishing the same job. The front regulator is just for those people who start the car w/o letting the oil warm up before driving. that's the only time it actually works. then or if the rear fails.
12-13-2006, 01:55 PM
#24
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Join Date: Dec 2003
Location: Minneapolis,MN
Posts: 500
Originally Posted by Buckyfd3' post='836558' date='Sep 11 2006, 10:50 AM
I had them soaked for 2 days in industrial degreaser, was a f*ck-up from the start to be honest. A broken side seal didn't do the job, just got stuck.
Ive never had a problem using 3M Carb Cleaner. Hacksaw blade seems a bit agressive, try using old side seals. If you break a bit off the end you have a nice square edge to scrape out the carbon. But if you use the 3M Carb cleaner its more like cleaning out goop than hard carbon.
Use an apex seal end on the rotor face to scrape off large bits of carbon then use a 3M scotch brite pad soaked in carb cleaner for the rest.
Ive tried soaking rotors in just about everything. In my opinion its just a waste of time. Elbow grease works the best
12-13-2006, 02:04 PM
#25
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Join Date: Dec 2003
Location: Minneapolis,MN
Posts: 500
Originally Posted by heretic' post='836897' date='Sep 13 2006, 03:45 PM
NAPA brand carburetor cleaner, and Mopar combustion chamber cleaner are neck-and-neck as far as winning the title for nastiest and best spray-type decarbonizing chemical.
If you really want your rotors CLEAN, get a bucket of Berryman's carburetor dip. It is not as cheap as a few cans of carb cleaner, but it requires zero work. Just remove all plastic or rubber items that you don't want destroyed, put the part in the bucket, ignore it for a day or so, then pull it out of the bucket and immediately rinse it off in kerosene (or Diesel fuel). With maybe a very light scrubbing, your rotors will look new.
Just make sure that there are no "organics" on the part! You will be able to wear your oil O-rings as big, thick, squishy, stinky belts, and play sloppy Ping-Pong with the corner seal rubbers.
The old guys in the shop I was working at told me that stuff will do bad things to the rotor bearings. But hell yeah, it works great on carbon. Just a bit too nasty for me to keep arround.
01-01-2007, 11:18 AM
#26
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Join Date: Jun 2004
Posts: 524
Originally Posted by Hyper4mance2k' post='848914' date='Dec 13 2006, 02:17 AM
It's the same concept as cutting your springs. adding the shim tightens up the front spring making it relieve later.
Apologies for the dead thread, but I found this while searching and this needs to be clarified.
TRUE - cutting the spring makes it stiffer.
However, we aren't necessarily concerned with having a stiffer spring. We're concerned with requiring enough force on a spring to move it to a certain point so that the oil can bypass. This amount of force divided by the the area of the plunger makes for the blowoff pressure.
To use your suspension analogy, we shim up the spring in order to require more load on the car before the suspension compresses to a certain ride height. Cutting springs does make a car stiffer, technically, but it sits lower and bottoms out easier.
We used to take the secondary diaphragm out of the stock 4 barrel carbs on the 12As and cut 1/3rd to 1/2 of the spring out so that the secondaries would open more quickly. It'd beef up the midrange nicely. ****-retentive types would even keep a supply of springs at the ready and use them for tuning the secondary opening.
01-09-2007, 12:38 PM
#29
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Join Date: Jan 2004
Location: Central Ohio (Hebron) Zephyrhills Fla.
Posts: 1,322
Originally Posted by GMON' post='848981' date='Dec 13 2006, 01:04 PM
The old guys in the shop I was working at told me that stuff will do bad things to the rotor bearings. But hell yeah, it works great on carbon. Just a bit too nasty for me to keep arround.
The piece of a side seal sharpened to a nice point and wrapped in tape for a better grip is the premo tool for the job.
A cleaner containing a caustic soda works great on carbon. Oven cleaner works well and can be used without getting it on the rotor bearing. Castrol super cleaner in the purple jug works well and does a good job on trailers sides where aluminum has left streaks of black down the sides. Scrub with super cleaner in hot water, and wrinse off immediatley with cold water so as not to discolor any aluminum. This will ruin a rotor bearing if you soak the whole rotor in it. Wear rubber gloves. Caustic soda will desolve your hands as well.
The side seal and apex seal grooves must be completely clean before assembly. Don't bother to assemble otherwise.
If you want to go over 9,000 RPM with other than FD rotors ( I think they are already narrower than early rotors, but check me on that) you really do need to cut the sides down a bit. The .010" off of each side is fine. The longer crank and heavier rotors of the 13B bend the crank sooner than a 12A.
When you scream the engine, you need at least 100 PSI of oil pressure. That puts more oil into the rotors from the oil jets than is requred for rotor cooling. It foams the oil more and lowers idle oil pressure, (from foaming the oil. So you install smaller than stock jets like a 200 Weber main jet, or braze the hole shut and drill it again with a 200 drill bit. I run a 180 Weber jet but I have a bunch of oil cooling.
So, if you do that and run 100PSI or more, oil pressure you are still getting more rotor cooling flow than the stock jets give you with stock oil pressure.
If you remove the stock ***** and springs, you get lower idle oil pressure. That is what th ***** and springs were for. It also lets the rotor come up to temp quickly at idle, for better EPA numbers. So long as the low oil pressure is caused by the ***** and springs being removed and not some other problem, just ignor it. Almost any amount of idle pressure is just fine. The bearings are huge and lightly loaded. It will be fine.
The stock 40MM pump in good condition is plenty for just over 100PSI. The FD pump is 50MM and inlets oil from both ends, and performs even better.
With a dry sump pump I run about 80 PSI at idle and 100 PSI at speed. The 100 PSI is plenty for a 9,600 RPM shift point in a 12A.
Lynn E. Hanover
01-10-2007, 09:58 AM
#30
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Join Date: Jan 2004
Location: Central Ohio (Hebron) Zephyrhills Fla.
Posts: 1,322
TRUE - cutting the spring makes it stiffer.
[/quote]
It does indeed.
Did you know that there is no such thing as a coil spring? Yep, its true. All a coil spring amounts to is, a small package into wich we can fit the correct rate torsion bar.
Torsion bars are rated in pounds of torque per degree of twist. Coil springs are rated in pounds of resistance per inch of compression. But look at the coil spring, and see what is happening when we compress the spring? The wire is being twisted, or a torsional load is being applied (because it is in fact a torsion bar).
So, if you wanted to increase the rate of a torsion bar, and keep the same length, you would make it thicker
and so, stiffer. (higher rate). If changing the design were not an option, you could shorten the bar, and do the same thing.
So, if we wind the torsion bar into a column so it works in a smaller space like on a coil over shock for example, we could make it stiffer by making the bar thicker as before, or shorten the (bar) spring. Samo/Samo.
All is fine as long as the shortening process is compensated for the length change. Otherwise we get stiffer spring (higher rate) and a lower car for example, or stiffer spring and a distance of free travel before the spring is engeged at all.
In the case of a pressure relief valve, there is an amount of preload that is used to get the plunger pressure into some specific load range for the oil pressure the valve was designed for. Say in stock form the valve cracks at 80 PSI. And you want the crack pressure to be 100 PSI. You could add some washers to the fixed end of the spring to increase the preload. This works just fine and is the most often found modification.
It is not the only feature of a relief valve that must be accounted for however. The crack pressure is surely
the primary goal, but in addition the method that is used to vent the spent oil must be a concern. The plunger must travel far enough to uncover the entire port for venting the oil. Nearly any amount of port exposed will work well when the engine is warm, but what if the oil is cold and like cement when you fire it up. Then you need the plunger back far enough to expose the entire port, or you break an oil pump or pop a cooler or an oil filter can.
So there are two perameters to consider when modifying a relief valve. The cut spring must be shimmed enough to compensate for the missing length and depending on the new rate, a bit more to arrive at the correct preload for the new pressure desired. The final test is: can the plunger uncover all of the port before the spring stacks and prevents further movement.
Same for the incut but shimmed stock spring. Can you shim it (preload it) enough to arrive at the new oil pressure and still maintain enough travel to uncover the entire port.
Once you have shimmed the valve, put a pin punch into the threaded end (where the valve is exposed to pressurized oil) and press the plunger back to be sure it exposes the whole port.
You can check the cracking pressure by assembling a rear iron and using an air hose to presurize the oil gallery. Adjust the air pressure up a bit at a time until the valve cycles. Check the air pressure gage. There is your cracking pressure.
Lynn E. Hanover
[/quote]
It does indeed.
Did you know that there is no such thing as a coil spring? Yep, its true. All a coil spring amounts to is, a small package into wich we can fit the correct rate torsion bar.
Torsion bars are rated in pounds of torque per degree of twist. Coil springs are rated in pounds of resistance per inch of compression. But look at the coil spring, and see what is happening when we compress the spring? The wire is being twisted, or a torsional load is being applied (because it is in fact a torsion bar).
So, if you wanted to increase the rate of a torsion bar, and keep the same length, you would make it thicker
and so, stiffer. (higher rate). If changing the design were not an option, you could shorten the bar, and do the same thing.
So, if we wind the torsion bar into a column so it works in a smaller space like on a coil over shock for example, we could make it stiffer by making the bar thicker as before, or shorten the (bar) spring. Samo/Samo.
All is fine as long as the shortening process is compensated for the length change. Otherwise we get stiffer spring (higher rate) and a lower car for example, or stiffer spring and a distance of free travel before the spring is engeged at all.
In the case of a pressure relief valve, there is an amount of preload that is used to get the plunger pressure into some specific load range for the oil pressure the valve was designed for. Say in stock form the valve cracks at 80 PSI. And you want the crack pressure to be 100 PSI. You could add some washers to the fixed end of the spring to increase the preload. This works just fine and is the most often found modification.
It is not the only feature of a relief valve that must be accounted for however. The crack pressure is surely
the primary goal, but in addition the method that is used to vent the spent oil must be a concern. The plunger must travel far enough to uncover the entire port for venting the oil. Nearly any amount of port exposed will work well when the engine is warm, but what if the oil is cold and like cement when you fire it up. Then you need the plunger back far enough to expose the entire port, or you break an oil pump or pop a cooler or an oil filter can.
So there are two perameters to consider when modifying a relief valve. The cut spring must be shimmed enough to compensate for the missing length and depending on the new rate, a bit more to arrive at the correct preload for the new pressure desired. The final test is: can the plunger uncover all of the port before the spring stacks and prevents further movement.
Same for the incut but shimmed stock spring. Can you shim it (preload it) enough to arrive at the new oil pressure and still maintain enough travel to uncover the entire port.
Once you have shimmed the valve, put a pin punch into the threaded end (where the valve is exposed to pressurized oil) and press the plunger back to be sure it exposes the whole port.
You can check the cracking pressure by assembling a rear iron and using an air hose to presurize the oil gallery. Adjust the air pressure up a bit at a time until the valve cycles. Check the air pressure gage. There is your cracking pressure.
Lynn E. Hanover