i know you can look in the FSM to see what counterweights are for wwhat year and turbo or non turbo. i also heard that it depends on the rotors you have so lets see if someone can clerify this for me.

i am building a weird engine setup, i have all s4 tii irons, i have s5 N/A rotors and rotor housings, im gonne be using a tii flywheel and front cover, i also am using a tii oil pump can some one help me out with what counterweights i need for this frankenstein engine,

any help appreciated thanks

 

You are using s5 internals, therefore you will need an s5 counterweights....

A front s5 n/a or tii counterweight and a rear automatic counterweight with aftermarket flywheel or rear tii stock flywheel will work...

 

someone else can confirm this, but I think it is also dependent on if your using the stock TII flywheel. The rear counterweight is built into the flywheel so if you use that it depends on if the flywheel is s4 or s5. I thought it didn't matter what internals you use (rotors and e shaft). I am using a GSLE eshaft, 91 rotors, and s4 front, rear counterweights, and an aftermarket flywheel. I haven't but the motor together yet, but that's what I plan to run.

 

The whole point to keep the engine in balance is because the internals.... You will have lots of fun with the engine set up the way you plan on having it....

My post above stands true and correct. By the way, forgot to mention the rear must be an s5 auto counterweight or s5 tii flywheel (i was assuming you would know that).

 

Ok thanks for the clericication, I'll have to get a rear tii counter weight, and what is an auto counterweight? Not like a counterweight off an engine that had an auto tranny right?

 

The engine ran perfectly with the 85 eshaft, 91 rotors, and 85 front counterweight and flywheel. The only reason I'm going to the s4 weights is because I already have them both with a rb flywheel. Since it worked with the 85 counterweight and flywheel this should work to. *fingers crossed lol*

 

Yes, off an engine that had the automatic transmission. You will need this if you are running a lightweight aftermarket flywheel. otherwise, don't worry about it too much and just use the stock s5 tii flywheel, it has the counterweight built in.

 

Ok so ur saying I can use a S5 NA or Tii front counterweight and a stock s5 tii rear counterweight? If i understand right it seems there is no difference between na and tii front counterweights.

 

yes.... as long as you stay within the series of internals and front/rear weights the engine will be balanced...

 

correct
there is no difference between the NA and turbo counterweights from the same series
infact,, the turbo uses the NA front stack ,, as this is what the part numbers reflect
N327 = s4 ( NA ) , N350 =s5 ( NA ) ,, there is no n318/n332 ( s4 turbo ) or N370 ( s5 turbo ) specific front weights,, they use the NA numbered components

----------------------------

in answer to the original post,, weights must come from the same series as the rotors used, NA or turbo does not matter

if choosing a stock rear flywheel ( and why would you ?? ) then you must choose a s5 one to match the s5 rotors,, SIMPLE

else,, you would choose the N350 ( s5 ) rear weight from the auto equiv for the light billet flywheel to fit onto
and BTW FD and cosmo RE rear weight is the same as s5,, as all have the same mass rotors
( but not necessarily the same part front weight ,, as manual FD has the large torrington race )

if you have some other combo of weights ,, and "think" that it works
then you are VERY mechanically unsympathetic ,, and entirely ignorant to the issues at hand

 

Ok that's what I thought after u explained it the first time i was checking lol. And I'd probaballt just use a stock s5 tii flywheel to make the rear counterweight issueore simple, unless there is a serious advantage to haveinf an aftermarket flywheel for a daily driver?

 

You better hope and pray. More then likely you were misinformed as to what you are really running.

Counterweights MUST match the rotors, if not you get violent shaking and you chew up your stationary gear bearings.

 

Using an aftermarket flywheel does have some gains in the lower gears, but not enough that you absolutely have to have it.

 

If he is using the s4 counterweights with the s5 internals, the rotating assembly must of been sent out to be balanced. That is if.....

 

Well, the engine is an s5 engine but the rear flywheel is a 215mm fb flywheel unless there is a 215mm s5 flywheel with the counterweight built in I haven't heard of.

I was dead set on what your saying , but until I came across this motor. I haven't pulled it completely apart yet for the rebuild, but I will post what I find out. I'm not saying im right and everyone else is wrong, i'm just stating what I have here in my possession.

 

As of right now the motor has the 215mm flywheel with the built in counterweight, while being a S5 motor. I was told the rotors are from a 91 as well, but the eshaft for a fact is from an fb 13b. It may be possible I have that entire rotating assembly, but the irons are S5. I will be able to get a definite answer once I open it up. I figured if this is an S5 motor with S5 rotors and early 13b counterweight and flywheel, it should work if I put the s4 counterweights in there. I hope that cleared some things up in my case. Before anything is put back together I will definitely know what I'm dealing with here.

 

e shaft if earlier than 1986,, will use a different pulley bolt and has no thermal pellet
as for 215mm clutch combo ( 8.5 inch clutch ) ,, i have occasionally seen s5 engines fitted with a 79-80 13.9 kg ( 30 pounds ) 12a stock flywheel
( not factory,, one of the local shops is doing it )

needless to say ,, i am quick to point out the haphazard and recommend the full billet flywheel and CORRECT counter weight

i believe the shops error is in that the original 12a flywheel 74-82 is 10.15 pounds while S4 13b flywheel is 10.04 pounds
( hence early 215mm 12a flywheel will not be far off the correct mass for s4 engines )

and that 83-85 12a flywheels are 9.60 pounds,, and s5 13b flywheels are 9.54 pounds
-- making the 225mm 83-85 12a flywheel a close enough match ( for some ! )
[ though why you wouldnt instead use the s5 NA 225mm flywheel to give the CORRECT mass but suit the NA gearboxes beats me ]

if you compare rotor mass,, its even clearer--
12a rotor 74-82 is 4603 grams ,, 13bt s4 rotor is 4553 g
12a rotor 83-85 is 4353 g ,, 13bt s5 is 4328 g

personally,, if you require the 215/225 flywheel suit your gearbox ,, get the correct auto counterweight and a billet flywheel
-- nothing is riskier to your health than bolting up a worn out cast 30 year old flywheel and applying 50- 200 % more grunt than stock through it !
( did you know 90% of the strength of a cast object is in the first fractions of a millimeter depth! )

the billet flywheel gives much better response,, and much better safety ,, 2 birds for one

 

yes, the eshaft has no pellet or even space for one, that is how I know it is definitely pre 86. What I just explained is what was on the motor already. I have no intention of reusing the stock fb flywheel. I am just trying to figure out how that worked on the S5 and everything was in balance. I have a RB light steel flywheel that I am going to use. Once I get the motor apart I will no for sure what front counterweight is on it, then I can get the rear counterweight for use with the RB Flywheel. I already have an s4 flywheel, but I can't use that it seems and according to what you said the fb flywheel that is on there now is closer to the weight of the s5 flywheel so that is why it works. This is pretty much the answer I have been looking for, but once again I can verify the rest of the internals "except the eshaft" until I get the motor apart.

 

*Update if anyone was wondering* well finally got the motor broken down and it turns out they are not s5 rotors. They look like s4 rotors but I think they may be gsle 13b rotors. The reason I say that damn near the whole motor was gsle. Front, the rotor housings, e-shaft and flywheel. So I guess I should start looking for a gsle 13b counter weight eh.

 

GSL-SE/RESI engines have cast face in the rotor bath and 3 mm apex seals and 1mm side seals
-- they look a lot like the rx4 rotors,, though are 9.4:1 instead of rx4 9.2:1
rx4 ones have 1757 stamped on the face,, the GSL-SE dont

the GSL-SE/RESI engine will have the earlier oil pump from the 12a
( but with high volume taller 17.5mm rotor )
and also coolant seal grooves in the housings
primary port is usually tiny ,, and aux ports smaller than the s4/5 engines

PS you need the rx4 counterweight,, or the N304 one