eh.. i may be stubborn and try it anyway--not because i think you're wrong, but because i'm cheap

if i blow it up, at least i will have learned something

 

Such as? I'm extremely interested in this idea, but totally unfamiliar with drysump setups.

 

^ i'm in the same boat....but the pricetag doesn't justify me doing it to a beater car

 

Pineapple and Mazda Performance.

 

so I read this whole thread twice and still not sure about which motor mounts to use with the stock fd subframe and fd rear plate. Do u use a custom motor mount, fd motor mount or 20b motor mounts? In this thread https://www.rx7club.com/20b-forum-95/20b-fd-subframes-395495/ they say that custom mounts are needed and that is why i'm confused. One last question, is the front cover and sump kit from Mazda Comp the only option for dry sump setup? because not everyone is able to order from there. thanks guys this is good thread for mounting option

 

Besides the MFR. Dry Sump front cover, there are other alternatives
You can use external Dry Sump pumps, as like what the Nextel Cup Nascar engines use.
I've posted 2 Rotary engines we've done in the past with external dedicated pums.
Go to: http://img.photobucket.com/albums/v112/GT1-20b/
1) is a PP. 13b w/ a Peterson 3 stage pump.
2) is a 12a Formula Atlantic w/ a Weaver 3 stage.
Both systems work well, the external pump syst. is initially a bit cheaper, but much more complicated. In the end, they both will set You back about the same.

 

so how much would it be door to door for you to build me one of these dry sump engines?

 

my friend dick lambert has a 20b fd. i have helped him a bit w a few mechanical issues. it is a pretty clean 95 CYM and a ground up re-do...

his car runs either the pettit (or something similar) subframe w extended steering arms off the upright. it was built, i understand, by a mazda engineer in florida. dick has owned it for a year and a quarter. i did drive it to the rotary revolution ( you are all going this april 21st, right?) so i have about 700 miles with it. it has a T66/ fresh Pettit motor/haltec e11.

as is, the car drives poorly. as soon as you turn the wheel. it has toe in bumpsteer. i did a bumpsteer on it and it specs out like it drives... at one inch of bump the toe in is .249! at 2 inches .288 and 3 inches .531!!!!!!!!!!!!!!!!!!!!!

here's what happening:

with toe in on bump, the outside wheel turns in response to the steering wheel. then the car rolls and the front outside wheels goes into bump starts turning more, which creates more roll and more turn in. yikes!

in order to keep the car from continuing this spiral a counter turn with the steering wheel is needed to correct every turn.

having raced and designed and built SCCA tube frame (mazda) racecars for 22 years i can not tell you how bad this dynamic is for the car and driver. if it was my car i would not have driven it around the block before fixing it.

bumpsteer should be toe out and be at most .01 to .02 per inch of suspension travel. this car has half an inch!!!!!

i do not know if it is Pettit engineered or a knock off, or just someone's project so i am not laying blame anywhere. i actually have the Highest Regard for Cam Worth.

i will be fixing Dick's car when i get the time... it will envolve relocating the outer steering pivot point downward.

if i were to do a 20b fd i would mount it low for center of gravity reasons, and would absolutely not disturb the steering. whatever engineering it would take i would do to respect the above 2 essentials.

as to dry sumps...

i ran the Mazdacomp dry sumps on my cars. it is a trick setup as it eliminates putting an external huge pump on the engine... lots of heat generated, belts that break etc. i ran Roger Mandeville's wet sumped motors and Daryl Drummond's dry sumped motors... no power diff from the diff oiling systems. i ran 12 quarts of oil w the dry sump. the tank is cumbersome for a streetcar and would have to be externally vented if inside the fd. it is also hot. it is generally tall. the oil enters the tank from the top and flows down thru baffles to de-airate it. i would just make a custom oilpan to keep it simple..

i did scale dick's car (thread entitled "just scaled a 20b fd") and was impressed at the fact that the car was fairly light and not very nose heavy, even w a-c etc. once the suspension is straightened out it will be an excellent car.

howard coleman

 

so dry sumps are not really needed for street driven cars and it dosn't make ur car more realliable if it is mostly street driven. Am i right or wrong?

 

When mounting a 20b on to a fd subframe which motor mounts do u use?

 

Howard, does Dick's car not have any modified spindles? Rxman720b has an older Pettit style sub-frame and modified spindles. He claims with linear springs he doesn't have any bump steer issues. Here's a pic!

 

"so dry sumps are not really needed for street driven cars and it dosn't make ur car more realliable if it is mostly street driven. Am i right or wrong?"

you are right.



"does Dick's car not have any modified spindles?"

yes, dick's spindles have been lengthened but apparently not enough.

howard coleman

 

thanks howard

 

Mr. Coleman IS 100 % CORRECT !
A STREET CAR, regardless of power DOES NOT NEED A DRY SUMP !
A street car will never encounter the conditions that warrent's a Dry Sump system, unless it's a 911, & that's only due to "PACKAGING".
By designe, a Porshe is a boxer, & the engine's cylinders sit 4" up off the ground.
No ROOM for a sump of ANY kind.
Other Exotic cars may have it, or incorporate it, but only because within their price tag, (it) can be included. Not cause it is nessesary.
I don't care how fast anyone THINKs they will drive their Fd's. You will never in you'r right mind, put your self in a senario were a dry Sump is gonna help keep the engine together, longer, while driving a STREET CAR on the STREET !!!

The expence of buying & building a Dry Sumped engine, FAR EXCIDEDS the cost of: A custom made oil pan, a little creative thinking, & some minor fabrication.

The 3rd. gen Rx7 is a "Race car in street clothing" A wonderfull, and enjoyable
enthusiast car. A car to be driven, with ALL the confidance it PROVOQUES !

Do You'r self a favor, DON't try to re-engineer the "wheel". A group of japanees engineers already made it "round" FOR US TO ENJOY !

 

Well,
It depends on what type of engine, and its intended pourpose.
Add to that the cost of the Dry Sump system with all the fitting, belts, pullies, hoses, and internal modifications, Include the freight charges for a door to door delivery servise, and You got the cost !
I think You probably have a good idea.
If serious, PM a description of what You want, what its going to go into, intended type of use, Turbo or Not...... ALL SPECIFICS. ......

GT1-20b

 

thanks gt1-20b that's exactly what i thought and i hope everyone will know this is a mod for serous track cars only and not for us regular folks. so happy i dont have to fork out that much cash on top of an already expensive conversion.

The 3rd. gen Rx7 is a "Race car in street clothing" A wonderfull, and enjoyable
enthusiast car. A car to be driven, with ALL the confidance it PROVOQUES !

that's a good quote hope u dont mind if i use it.hahaha

 

nice post gt1-20b the fd is a racecar.

howard coleman