sa22rally

Hey Guys im going to rebuild my 13 b 4 port in my 1st gen rallycar after over reving the car at a race last week. This is my 1 build where i have the time and money to spend the other 2 rebuilds has been last minute befor racetime.
So what mods do i need to do while im in there. i have ordered the raceports from pineapple.
Ive read about things like shaving of a bit of the rotortips to clearence and butting a spacer in the oil regulator in the back. but what kind of mods are needed and is there anything else i should do.
This is also my first rebuild without guidence.
im running a 48 mm IDa weber what choke should i use for torque 38 40 ore 42 mm?.
Also the guys who has tought me a bit about these engines uses Vaseline for lubing the seals while assembling. and Lock-tight to glue the apex seals together is this the right way?

Best Regards Rasmus Andersen Denmark

sa22rally

And also im running premix can i just remove the stuff for the OMP?
And what are you guys usen as fuelfilters i have to change mine every 10 gallons because of oil clogging it im running 1½ % Petro Canada Two stroke oil in 99 octane

Joe428

Can't help you with the rebuild questions but for premix I run 2 stroke oil at about 100:1 ratio and never had a fuel filter issue. I run Wix filters. For the OMP, if you're running premix you can remove it and just buy or make a cover for the hole that is left. Several companies sell block off plates but it wouldn't be hard to make one if you gave the tools.

diabolical1

iTrader: (3)

since this is a race car, you'll surely want to do oil mods. little things that just make sense (like MSP or REW corner seal springs and hardened bearings) are also things to consider.

what porting are you using and what usable terminal RPM are you planning. many things seem like a good idea and i'm sure they are, but i don't know what kind of budget you have. so things like race clearancing (rotor tips and shoulders) and race balancing may or may not be NECESSARY ... even though they may be a good idea. if you have a radical port and plan on BIG RPM, then they will become necessary! which apex seals you run will also be a question thrown in the mix.

if you look up some of Jeff20Bs posts on the subject of Vaseline (petroleum jelly) use may or may not interest you. i don't necessarily disagree with him. i think his posts have merit and i find them very intriguing. however, i still use petroleum jelly simply because i find it will hold some things in place better than motor oil when you turn them upside down. i really don't experience excessive smoking either.

i don't know about using Loctite on the apex seals ... personally, i would not. i use Krazy Glue (it's a brand of super glue here, so i don't know how available it is to you). you will want something that is strong, but will break free either when you torque the tension bolts OR when it meets the gasoline. i don't know if Loctite does either.

i know 48s used to be the **** way back when, but in this day of 50 and 55 mm throttles being used on the street, i don't know if you'll want to choke a 48 down too much. i would imagine your top end would suffer and since you're actually racing ... i would say use the larger choke. you should be able to play with your powerband with phenolic spacers and velocity stacks instead.

i had a problem with premix clogging on my Rx-8, but i've never had any problems with clogging on my Gen I (and keep in mind i ran in addition to the MOP and also there were times when i mixed pretty heavily). i just ran two of the stock filters - one in the stock location and one just before the carburetor.

Jeff20B

iTrader: (13)

Yeah, superglue or crazyglue (krazyglue) is what I use on apex seals to hold the end piece on. Don't go bigger than 79.95mm because sometimes they don't pop apart as the tension bolts are torqued. This leads to increased friction and harder first starts. I always glue them at 79.95 or shorter. Others will disagree.

Wheel bearing grease to hold corner seals in when you install a rotor. It also keeps coolant seals in place when you install a rotor housing.

Engine oil on the side plate surfaces as an assembly lube. Only use as much as necessary; don't go overboard because it leads to first start difficulties ie plug fouling.

RTV on the rotor housing legs to prevent oil seepage.

I don't use loctite, vaseline, hylomar or assembly lube common to piston engine builders.

My engines' first starts are fast and easy. Often requiring only 1 second of cranking.

sa7

iTrader: (13)

Jeff20B - What do you use on the coolant seals if you don't use Hylomar?

I rebuilt my bros S5 T2 engine last year and followed Aaron Cake's video pretty closely, since it was a good reference for my first build. I used Hylomar but it was a bitch to work with, so I'm curious to what else could be used for my next build.

sa7

iTrader: (13)

Never mind.. Just reread your post, and you clearly say wheel bearing grease lol

Jeff20B

iTrader: (13)

Wheel bearing grease could work for you. It is sticky enough to hold the coolant seals in place and is super easy to clean up compared with hylomar. You only use just enough to do the job.

The wheel bearing grease was actually suggested by j9fd3s. I was looking for something other than hylomar because I hated working with it. And vasoline sucks to work with too.

Aaron Cake uses way too much vaseline. I don't use it at all anymore.

DreamInRotary

iTrader: (49)

Lots of good info here, thanks for the replies guys!

sa22rally

thansk alot guys good answers
I have ordered the Raceports from pineapple both intake and exhaust.
i also ordered the havy duty o-rings from pineapple so my concerne is also if any of the grease/vaseline will hurt the o-rings.
I dont want high RPM because my banker dont think its a good idea.
I would like it to pull from about 4000 rpm to 8000 im not going any higher.,

What kind of oil mods do you recomend besides shimming the oil return valve.
How do i race clearence the rotors i would like to do that just for peace in mind.

I am planning to use original 2 piece apex.

I really have no goal in terms of power other than i would like to have a powerband starting from 4-5000 rpm. and i want to do everything my self just like the rest of the car.
But i would also really like to have a engine that will last about 800 racing miles. .

Please keep on bringing all that great info and thank you

diabolical1

iTrader: (3)

funnily, i've never thought of the heavy grease before. i actually have a rebuild coming up (hopefully in the next month or so, if i can make the time) so i will be sure to try it. it's bloody genius! i mean, it has the stickiness of the petroleum jelly and i pretty much ALWAYS have some in the garage. looks like i may be abandoning petroleum jelly in the near future, too. old dog, new trick, eh?

i've never used Hylomar a day in my life, so i can't speak on it other than to say, i've found it seems to polarize people. if they like it, they like, but if they don't, they hate it. also, people seem to report that "it's not like it used to be in days of old."

diabolical1

iTrader: (3)

i'll defer comment on the Vaseline vs. Pineapple HD water seals simply because i've never used the Pineapple seals. i know i've seen people raise concerns over Vaseline and water seals in general in the past and all i can say to that end is ... so far as i'm aware, i've never had an issue.

if you're looking at a max of 8000 RPM, then it's totally up to you on what you want to do in terms of race clearancing and balance. most people use 8500 as the point where it becomes necessary. i think balance might be a good idea any way, but the factory balance should certainly be good enough to cover you.

1. crush your ROPR or get an REW one.
2. consider porting the pump passage and teardrops on the e-shaft (as long as the photos are still acctive, examples of both can be found in a BlueTII thread)
3. confirm which pump you have (i don't know what year 13B you have and if it's an old BIG PORT, then i don't know if the pre-'84 engine used the 17.5mm units)
4. consider what you want to do with bearings.
5. Weber jets in the e-shaft

Note: i'm too much of a chicken to remove the strainer from the pickup tube, so i haven't modified any of mine ... yet

as for race clearancing ... you were the one that first mentioned it - modifying the rotor tips and shoulders to prevent them "crashing" into the housings at high RPM. if you're asking how to actually do it, then i don't know. i mean, i've seen it done in Youtube videos, but i've never done it myself, personally.

should fall in line just fine with your 8000 RPM. i remember you have some rules that you had to adhere to for your class, so i don't know if you'd be able to use the newer 2 mm rotors in your old engine, if so, that's how i would go.

Siraniko

iTrader: (13)

Vaseline is fine and if you used too much crazy glue, pull the car around the block a few times but tranny must be in gear so the motor will rotate and eventually, glue will melt. Eshaft and ROPR mods are a must.

Jeff20B

iTrader: (13)

This is the right part to go in the eshaft if you must get rid of the checkball style for some reason.

Eccentric Shaft Oil Jet


I had several R5 shafts with these full flow squirters and they suck for street driving. Obviously a race car will be different. Link: Oil Pumps & Chains, Temperature & Pressure Adapters

DriveFast7

iTrader: (1)

For 8000rpm max you don't have to go full tilt, mainly concerned with reliability and longevity.

If you have the older 4 port (pre-86) then use the 17.5mm oil pump, preferably the Mazda Competition one with hardened internals. They'll last longer. Check your rear oil pressure regulator for wear on the piston, wear on the cylinder internal, and measure spring length. Many rotorheads don't realize these are wear items and need to be replaced when worn. At a minimum I'd just get a new piston and spring and the 85psi one from Mazda or Racing Beat is very nice or the FD one is less expensive. Check same on front regulator, and shim it at least 3/16". I removed the strainer on oil pickup tube and had a washer brazed on there, and ported it like a trumpet for much better flow. Put an in-line filter on an oil line, preferably the high pressure one that exits the front cover. Port the front iron where the oil pump mounts, theres pics of that on the innerwebs.

I've never clearanced the sides of a rotor, you won't need it for 8000rpm but can say that getting the rotating assembly balanced makes it rev very smoothly like butter.

The Rx-8 e-shaft is lighter and reasonably priced, and has had some high rpm clearancing done on the lobes the rotor bearings rest on.

Vaseline or grease can cause rubber seals to swell. For coolant o-rings, use GE silicone from the hardware store or some Molykote 111. The latter you can use on all kinds of o-rings: dowels, brake calipers, hot tub.

Permatex 230-85224 The Right Stuff Gasket Maker - 7.5 oz. on the oil pan.

Good luck, have fun.

sa22rally

Thanks alot guys all of your answers if very apriciated.
Do you have any links for guides on clearence and Oil Mods i Think its hard to sort out the good and bad threads

j9fd3s

iTrader: (3)

just to round this thing out, i'd use the clearances in the FSM, as that is correct. with the apex and side seals you want them on the tight end of the factory clearance, and with the rotor to side housing clearance you want it on the big side.

to keep the seals in the rotor, and lube up the dowel pins, i use a little heavy grease, it works just as well as vaseline, you just need something gooey to keep the seals from popping out, you could use anything gooey really. Aaron Cake uses way more grease/vaseline than i do, i just use a dab on each corner. the less you use the less it smokes on startup.

i use a little silicon on the water seals, you need something to hold them in place, and vaseline swells them a lot. plus with a little silicon the water seals come out looking almost reusable.

i've never been a fan of hylomar, its hard to get too, so i just use a little silicon

sa22rally

Thanks alot guys i think i have it figured out now.
now for another question unfortunatly i have blown both my housings and rotors. i do have 1 god housing and rotor on my shelf. my problem is that the housingi have isnt like the others ones og the ones i can get my hands on. the exhaust port is not as "tall" and the inserts isnt a mach either. uotside the difference is that around the sparkplugs there is a difference in the casting.
my question is will i be able to mix different housings by porting them så the ports mach and maybe swapping the inserts but how do i get the pins out that hold in the inserts.

Best regards Rasmus