Valves, crank.. measurements?

[VanSil-80]

so.. im currently rebuilding my f*** ca.
i have no idea how to measure the crank journal, and mains, for bearing clearance, and i cant find the clearance in the fsm.
and i dont have a micrometer.
i searched on here and couldnt find s***, so maybe im just retarded.
also, for valves, should i be replacing the valves with stock size valves or should i grind and get oversized.
i think thats it..
im sure i'll have more questions.
i'll get some pictures up later.

[tommey]

Do you have the old bearings? If so it says on them if they are oversize or not (usually).
Or are you putting the engine back together and want to check if the clearances is correct?
If so, go to your machine shop and demand a strip of plasti-gauge.
In any case, a machine shop will measure the crank for you for free.
I would go for stock size valves, it could be an idea to go up in the exhaust side if you are looking for big power.

[VanSil-80]

i just need to know how to measure my crank journals, to see if im going to need oversize bearings or not for my rebuild.
like, if my crank has worn at all. this is basically all i need to know, then i can buy the pistons and connecting rods, clutch, flywheel and HB.. sending it to the machine shop to be bored and assembled.

[float_6969]

The crank doesn't just "wear" out of spec. There would be OBVIOUS damage to the crank if it was worn. If you don't know the history of this motor and you think there is a chance that the crank has been ground for undersized bearings, then you need to buy a micrometer to measure the journal diameters.

I can tell you for a fact that every bit of info you would want to know about the crank is in the FSM. It's in the EM section, near the end. You can pick up a cheap digital micrometer from Harbor Freight for $30 that will measure accurately enough to tell you if the crank has been ground or not.

As for the valves, try lapping them, and see if there is any pitting in the valve seat. If not, you can just re-use the valves (as long as they're not bent).

[VanSil-80]

in the fsm its telling me to specifically measure the crank journals to see if i need oversize bearings or not.
but im an idiot and dont know how to mesaure, or what to measure rather, to determine whether or not oversized bearings are needed.

[VanSil-80]

agh, also another question.
if i went with a power fc, or something to that extent ( currently im just eprom) will my secondary butterflies be null and void, or does the power fc have nothing to do with the vaccuum lines controlling the butterflies. im looking to NOT eliminate them, as i'll be below 500 hp and i dont see it necessary to get a plenum.

[float_6969]

What don't you understand, what the journal is? How to measure the diameter of a circle? What diameter means you need to have the crank ground?

The power FC is a HUGE pain to tune with unless you're using a FCDatalogit. Then it works like most other standalones. They're getting kinda rare though, and for the money, you could run Nistune and be in the same boat and have a lot more support.

[blownhemi]

Do a Google Image search for "crank journal". I'm sure you will find illustrations on how to measure them.

[VanSil-80]

what standalone would you suggest other than going nistune?

[tommey]

SDS, vi-pec, MS. does not really matter.
Vi-pec does a plugin board at least.

[VanSil-80]

do most suggest nistune though?
i was reading up on it, it seems like a good option for sure. i dont find launch control really necessary, and i have a boost controller..

[tommey]

Nistune is a good option, i would take nistune over PFC anyday.

[VanSil-80]

so..
i have another question regarding valve springs.
im gathering all of my parts right now, ( valve seats ,seals, retainers, etc ) and i have come across a few different spring options.
supertech has the dual spring, tomei has single springs, or i can just go with oem springs.
im thinking supertech but i have no idea what advantage/disadvantage the dual springs have.

[D_Stirls]

Can you link me the Supertech double valve springs? When i was looking 18 months ago i couldn't find and double springs for a CA.

[NUTCSE]

Can you link me the Supertech double valve springs? When i was looking 18 months ago i couldn't find and double springs for a CA.

http://cgi.ebay.com.au/ws/eBayISAPI.dll ... K:MEWAX:IT

Double valve springs, spring seats AND titanium retainers!!!!!! Cheap as!!!

[D_Stirls]

spewin, i cancelled my plans for a solid head due to not being able to source a double valve springs and custom setup was way too expensive. I still haven't bolted my head on but since i have already spent $1500 on the head i'm not spending any more.

[VanSil-80]

so...
should i be going with dual valve springs?

[NUTCSE]

That really depends on what cams you are using. If your cams have lift of 10.35 or more then id be getting these othrewise tomei's are fine.

[VanSil-80]

i just have hks cams.
im basically buying all my s*** tonight when i get home from work.
so far,
pauter rods
cp pistons 83.5.
valve guides, springs, retainers, seats, valves.
still clueless as to what size bearings i need. i dont want to spin one once i assemble the motor so i have no idea what to do.

[blownhemi]

still clueless as to what size bearings i need. i dont want to spin one once i assemble the motor so i have no idea what to do.

There's really only one way to do it right, if you don't have a good digital caliper accurate to 0.005mm (0.0002 in.).
- take your crank to a reputable machine shop
- have them measure all 5 main journals (4 measurements PER JOURNAL at the very least around the journal surface, as per FSM EM-52 page; in a stationary position, top-down and left-right, on both ends of the journal. But a reputable machine will know this without telling.)
- have them measure all 4 rod journals (4 measurements at least, just as on the mains)
- compare the measurements you've got to the tolerances on the same FSM page; I think you should post them up here, too, all of the measurement data you get. Measurements need to be in either 0.01mms, or 0.0005 inches.

There's a way to do it even more right, which is to take the block with the caps and girdle to the machine shop, too, to measure the main bearing bores (where the crank main journals go to). Unless you have an accurate bore gauge besides that accurate digital caliper, too. Print out the "Service Data And Specifications" section of the Engine Mechanical chapter, EM-45 - EM-53, and hand it over to the machine shop with your crank (and block, if). Look up the tightening torque of the main caps, too, and tell it to them (40ftlbs., it's low compared to some other engines). After they measure everything, and looked at the service data, they will be able to tell you, if the crank needs grinding, and the bearing sizes you would need. But get the measurements from them anyway, and post them here to get a second opinion from the pros here.

[D_Stirls]

so...
should i be going with dual valve springs?

The need for double valve spring has to do with revs and cam lift. The Revs are due to springs having a harmonic range where they maintain their seating pressure, past this range there pressure is greatly reduced even to the point that there is no pressure. To counter this people fit stiffer springs but this can cause other issues due to the valves hammering the seats and really it is only a patch up for the springs not suiting the rev range.

The advantage with duel (and triple) springs is that as one spring moves out of its harmonic range the other spring take over. This way you can use two less stiff springs and achieve a better result than using one stiff spring. Also it is easier on the valve and seat as you aren't hammering the seat with a big cam and stiff spring.


There is a better video that this but i can't find it ATM;

See how the spring is bouncing, eventually they end up bouncing themselves off the seat, this is when you get to 0 seat pressure but before that the pressure is reduced.
[youtube]http://www.youtube.com/watch?v=kFbfHF9gzTY[/youtube]

[VanSil-80]

thank you giuys for the in-depth responses.
i just want to get this engine build on the go! i need my car for summer.
im going to take the block qwith the caps to a shop, as i dont have a bore gauge. i'll post the measurements on here, and im assuming you will suggest what size bearings to go with?
im so worried about that.
also, with the srpings.
i never knew it could go that indepth. im glad to have learned something.
i'll go with those springs, especially since its a bangin' deal with the seats and retainers.

[D_Stirls]

IF you aren't going past 8000rpm then you should be fine with singles and if you aren't going for solid lifters then you won't be reving past that point because you will then be having issues with the lifters.

Think about what turbo you are running and what the realistic maximum revs you will be running and that'll dictate how you are going to set you head up.

I went for a set from these guys; which set me back AU$125 as i decided that the cost of setting up a solid head and the fact that at the time i couldn't find and springs that could keep up so custom was the only option it was going to push my budget way past where i wanted to spend. If you are thinking abotu going solid down the track then buy the kit, if not just but some up rated singles.

I kept the best of the 3 heads to go solid if a wanted to down the track but at the moment i didn't have the $3500 that it was going to cost me to do it properly.