Well im ready to re-assemble the motor, and i go to put the pistons back in the way they came out...

When i Notice that they were in upside down, and the rods were facing the wrong way.

Then i notice the rings are loose, so i check and sure enough, they are 1/16 and im pretty sure i need 5/64 for these pistons!


So now im ordering new plasma molys, and i need to choose a new ring gap.

I also need to make absolutelly SURE these were in backwards, and i put them in RIGHT this time. Here is a picture to help explain....

The LEFT side is the tapered side, sticks out, and i assume points at the crankshaft. The other side is flat, no taper, and i assume points at the other rod.

 

Also check out where the valve hit the piston.

Whats wrong with this picture?

THE PISTON WAS BACKWARDS! if the valve releif had been faced the right way i would have had .300" more clearance for the valve to open!

 

See the huge valve releif? Should have been facing the other way....

IM NOT crazy right? the thing HAD to have been backwards!

 

Yep, as backwards as they get. I would have gotten beaten upside the head with a crankshaft at the machine shop if i put a motor together like that.

 

So the VERY FIRST PICTURE IS the CORRECT way to install the ROD...


RIGHT?

Or are you saying the picture is backwards...

and the final picture of the piston with the trough releif UP instead of DOWN is ALSO the correct way right?

 

labeled picture of the rod is correct. and the piston was upside down.

 

Rule of thumb on V8's:
Bearing locking tab goes toward pan rail

 

I am sorry but what does that mean? whats a locking tab and whats a pan rail?

 

Locking tab=little thing on the bearing that sticks out, fitting into the notch in the rod. pan rail=where the oil pan bolts to.

 

King talon , The chamfered end on the big end of the rod faces outside towards the respective crank journal end.

For example

> < > < > < > <

Valve relive should be "up" towards lifter valley



Order file fit rings and gap the rings for nitrous. You want a larger second ring gap to relive inter ring pressure.

 

life bites sometimes

 

Um, there's a rail on both sides...

But otherwise, yea, you got it... Was that thing run like that? If so I'd be pretty pissed at whoever put it together before (and dinged up the pistons...).

 

he asked what it was, not which one...anyway, locking tab towards the pan rail closest to the bank of cylinders that you are intalling the piston in.

 

ok hmm... locking tab... i dont understand how can you put those in wrong? the bearing only goes one way into the block and in the rods... if you try to put it the other way it wont fit.

That, im pretty sure, was done right at least. i cant say the same for the pistons rods and rings though.

I ordered some plasma moly's today, 5/64's like they should be for these pistons. I also got some .020 oversized bearings because the crank is turns .020 / .020 this time around.

i removed all the studs and chased the threads and put back in the main studs with some loctite....

I took apart the oil pump and sanded it down on each side some, it felt kinda rough. there are little marks in the top half of the oil pump where the gears had been eating away at it.

so now everything is clean clean clean, and im waiting on the crankshaft to come back and rings to come in so i can re-assemle.

oh stick around, this could get interesting! i can only imagine how it will run with everything installed correctly...

and suggested ring gap? I was thinking .020 top .021 bottom?

 

Run .006 to.007 per inch of bore on top ring and make the second rings .002 bigger than the top rings final number.

As far as the pistons go just make sure the relifes are up facing the lifter valley and the rod ends chamfered side facing towards journal ends > < > < > < > < Cant go wrong that way

 

Talon- You know the notches in the rod bearings we're talking about, right? There's one in the rod and one in the rod cap with a corresponding notch in the bearing itself that fits into it. Those two notches (rod and rod cap) should both be on the same side of the rod- not opposite eachother. THEN BOTH OF THEM should be pointing toward the OUTSIDE of the block for whichever bank of cyliders it's installed in. The rods themselves usually have a slight beam offset built into them plus a chamfer on one side of the bearing. And lining things up like this makes sure the offset is in the correct direction. You're right that in many cases you can't assemble it wrong, but not always.

Doing it this way is the ONLY correct way to install the rods. Keep track of the notches, face them to the outside and you'll do fine.

NOW FOR THE PART YOU'RE NOT GOING TO LIKE..........

You probably gotta get the pistons removed and reinstalled on the rods. If they simply installed the pistons backwards but they had the rods installed correctly the pistons will be facing the wrong way on the rods. No, you can't just install them in the other bank of cylinders. The pistons will be in the right orientation but the rods will be backwards.

The valve reliefs will always be on the opposite side of the rod as the bearing notches. If they are on the same side, you're screwed and you'll need to have the pistons removed and reinstalled the other way round on the rods. Sorry.

Look at one of your rod/piston sets as you read this. It'll make more sense that way.

 

Piston ring gap: CALL THE PISTON MANUFACTURER AND ASK THEM. DO NOT TAKE MY ADVICE OR ANYONE ELSE'S ADVICE ABOUT THIS. Differing piston material and design can have a HUGE effect on the ring gap required to work well with your application.

In general, for nitrous or forced induction on a street motor you want to go about .005-.007" larger than whatever the N/A ring gap would be. BUT you still need to know what that gap is and only the piston manufacturer can tell you this.

 

here does this help?

http://outlawperformance.com/images/...5-03%20(3).JPG

 

Well, it's not so bad, he's got floating pins, so as long as he can get those #$%@ spiro-lox out he can turn them around himself, no biggie.

 

Spiro-locks. Gotta love 'em. Getting them out is not too tough- small pick or screwdriver to get at the end and a set of needle-nose pliers to pull them out from there.

Putting them in is easy once you learn the trick- gotta stretch them out before installing so they're a couple inches long end-to-end, not stacked flat like they come out of the package. Then they'll spin right in with a screwdriver working from the end.

 

yeah, just a little tougher getting them out especially if he hasn't done it before. i've almost always had floaters, but i still hate taking out all the locks(32 of them gets quite frustrating).

 

huh, I suppose that it had to happen sometime... Damon, I agree with everything you just said...

 

Crossfire- yeah, there's a first time for everything, eh? Heh heh. So many things can be done to one's own personal tastes and expereinces, but getting the rods and pistons in the right way around...... not really open for debate. Only one way to do it right.

406- You building a 16 cylinder engine? 32 Spiro Locks is a lot for a V8 using 2 per piston! Just kidding. I know what you meant. Besides, he only needs to yank out 1 for every piston. That's enough to get the wrist pin out, flip the rod and then put it back together the right way 'round.

 

my SRP pistons use 2 locks per side, 4 per piston. yeah, you're right about only taking 1 side out and flippin it.

 

Wow all the bigshots! I must be popular!


Just so you know... I DONT have spirolocks! these TRW's came with little U-shaped craps that pull out and in 1-2-3 easy done.

second of all, the pistons ARE on the rods correctly!
But when the pistons were put in upside down, that reversed the rods which is why everything was backwards! I knew which way they went when i assembled the rods.. but apparently the guy putting them in didnt!

So I can leave the pistons on the rods, and just put the piston right-side-up and bingo, the rods are facing the right way!

And those pistons in the picture look like my new JE pistons... 9.5:1 with 64CC heads? im putting them into a blown 383 with 6" Eagles. In fact tommarow i plan on clearancing the block for the crank and rods... any tips? It will probably be done before I read this again though! lol.

Anyways, I went to the machine shop today too and told the guy about what had happened. Im serious, he looked at the piston and shrugged, "Its a very common mistake, I see it alot" he says. "as long as your crank wasnt aftermarket with a chamfer, it really shouldnt matter much." implying that it doesnt really make a huge difference! But there is most definetelly a new ding in my piston where the valve smacked it, thats for sure. I filed all the little eye-brows down with sandpaper and a dremel to make all the sharp hot spots go away. go me!

STILL Waiting on the crankshaft! Darn thing is in hialea still. it better be frickin perfect! .020 over this time. ..

AND Piston rings? .006? .020? LOL we are all bass ackwards! That extra ZERO in the beginning shouldnt be there... I checked and the gaps should be .22 / .24 not .022 .024 thats a pretty tiny gap lol.

 

sorry, I scanned if somebody else has said this already but your valves will be bent upon close inspection (machine shop). sorry to be the bearer of bad news

 

OH yeah tom, I know, I had them replace the bent valve already. that was like 3 weeks ago, the heads were torn down and resurfaced (it overheated remember) and it got a valve job and some minor work. only 1 valve hit a piston, however. the other eyebrow marks in the pistons were already there when i got them! weird huh?

 

put in, and turned over by hand? same mistake, same result?

 

HUH? Put what in turned over what by hand what?

I dont even have the heads back yet, they just finished them like a day ago. im waiting on the crank. when i get the crank back and re-assemble everything should be peachy and perfect and ill have lots and lots of pictures this time!!!!

 

Previously put in, and turned over by hand? same mistake, same result?

 

I dont think so tom, Pretty sure they come like that but who knows? This is the only motor I've had them in and I've only had 1 bent valve, ever, so i assume either they are made like that or somone else had them and did it. but they are all semmetrical as if a machine put them there, so im just not sure. either way i smoothed them all out and made them flat and smooth so...

well you know. uh. yeah.

 

if the gap was .22 or .24, that would mean almost a quarter of an inch, there's no way that's right. mine are .019 and .022.

 

For tips on clearancing the block, just make sure you make enough clearance. Clean up the block as best you can or have it washed at a a machine shop after your done.

Sir run .22 inch of gap and your crankcase will be supercharged.

Thats nearly a 1/4 inch of gap. Is this your first time building a motor? Or did you mean a progressive 2000 shot.

Notice the .006 -.007 per inch of bore. For example on a std bore 350 chevy with a 4 inch bore. running nitrous, .006 per inch of
bore mean 4" times .006" which equals .024 ring gap.

Also engine builder used to keep the second ring gap tighter because #1 they belived since it did not get as hot as the top ring, the thermal expansion would be less and #2 they belived that less compression loss could be achived due to the smaller gap.

Speed pro engineering pioneered running larger second ring gaps. Nascar fully employs this technology today. The theroy is that by running a larger second ring gap the pressure between the top and second ring know as interring pressure drops significantly thus allowing the top ring to stay in a sealing seated postion longer on the compression stroke.

You can take my advise with a grain of salt but I dont think your autotuner is going to be able to corect for a 1/4 of an inch gap.

The trw's may feature a smaller rate of expansion compared to a je or ross. As suggested you can call and ask if there is no spec sheet in the box.

:lala:

 

Here's the damned manufacturer-recommended ring gaps and other info for those exact pistons, since nobody seems to want to actually call and ask them. I did.

N/A applications........................... Top Ring................Second ring

Cast Iron/Moly Faced rings:..........004" x bore............005" x bore
Ductile Iron rings:.........................0045" x bore.........0055" x bore

Blown/Turbo applications....

Cast Iron/Moly faced:....................006" x bore...........006" x bore
Ductile Iron Rings:.........................006" x bore...........006" x bore

Note: Federal Mogul/TRW/Speed Pro do not recommend the use of cast iron/moly faced rings in a forced induction application. They recommend the use of ductile iron rings only.

FYI: You'll drop some serious coin on ductile iron rings. Haven't often seen a set for less than about $80.

There's no way you could have known all this without contacting the piston manufacturer. This research took me all of about 15 minutes on the phone to their tech support guys and another 5-6 minutes to type this post. How hard is that?

 

Note that the top ring gap will be a total of about .006" larger for a blower application than it would be for a N/A application (.0024 blower vs. .0018 N/A)- just like I said. But you HAVE TO know where you're starting from- i.e. what your N/A ring gap spec is.

 

ok im stupid. On my Feeler guage lists the sizes as .18 or .20 not .020 or .018 So i initially assumed that it was .18...

LOL See? its not my fault i was just reading what the thing said...


And My RINGS are Plasma Moly, Which is what Speed-pro My piston manufacturer recommended for my application WAYYY back when i got them. They were $99 from summit...
and they are also 5/64 like they should be.

They also came with a paper, explaining ring gap. It also says to leave the second ring gap larger to help the top ring seal...

So it will come together fine.

And Today I am clearancing the block for my 3.75"crank and when i put the pistons rods and cam all in, I realized that there was nothing the clearance?? Everything turned fine and nothing hit or even got very close... except one counterweight got pretty close to the pan rail which i ground off happily (not the counterweight..)

And the rod to cam clearance is very good too... I wonder why?

3.75 Stroke, 6" Eagle I-beam, JE piston.

 

on a 3.75" stroke, the clearance is usually pretty good, as long as you run I beam rods. I'm running h-beam eagles, so i had to clearance the block more as compared to the same crank with I beams on my 383. i've never had cam clearance problems, with 5.7 or 6 inch rods, i beam or h beam.

 

Talon- a 383 I built a few months ago also cleared with NO grinding ANYWHERE. I never had that happen before. Weird thing is that the previous engine, which used the same casting number block, required quite a bit of grinding to clear (the entire rotating assy. was swapped in-tact from the old block to the new). Only difference was the new block is a 2 bolt version of that casting number, the old one was a 4-bolt. Go figure. Count your blessings and don't expect it to happen that easy again. Especially not with beefy aftermarket rods.

 

Well i began assembling it tonight for real, and so far so good.

Im just worried about the cam though. If i put the cam in, and turn it by hand, it can hit the rods. problem is, the cam doesnt turn by hand, it turns by timing gear... so im hoping that during the course of running the lobes are always far enough away from the rod bolts to miss them...

But I gain confidence knowing thats usually not the case.

As for the block, the rods clear all the way around no problems now.

now my 355 with simple Eagle H-Beams needed grinding on about every bore at the bottom. thats with stock 350 stroke! man what weird stuff.

I got some pics ill upload later.

 

Yeah, really no way to know until you have the actual chain you are going to use in final assembly on and the cam degreed in however you need it to be. Mild flat tappets usually clear. Usually.

BTW- the directions you were referring to regarding ring gap were from the PISTON manufacturer, yes? NEVER EVER use the specs from the ring manufacturer. They don't know exactly what pistons those rings are going on. And it's the pistons that make all the difference. If they're from the piston manufacturer then the specs should be exactly what I posted since I called Federal Mogul and asked them myself, using the actual piston part number from one of your pictures.

 

FWIW,
I'm using a 91 350 truck block. All eagle 4340, h beams 3.48 stroke.
I had to clearance all the pan rails for the rods.
I don't know how big that cam is but like it was stated before it
should clear once it is in correctly.

 

Well i put together the bottom end on my motor tonight. All went well, pistons went in rightside up and rods went in right side.. uh... in. i mean out. um you know what i mean.

I put the oil pump in too, after sanding it down on the inside (few days ago) and it went in well. put the windage tray on too. it misses by a 1/8 inch i would say...

oil pan is on now. dont worry though, i got lots of pictures. right now they are outside in the shed however, oh well.

Tommarow comes heads / intake and valvetrain. yes the cam is also in, and i dialed it in perfectly.

 

Some pictures weee

 

bottom end

 

pi

 

head

 

This is how far i got tonight:


now tommarow the fun fun fun of all the electrical stuff comes together. hopefully it starts this time without eating 3 battieres.

 

ITs running now, but im having a crapload of problem with the electrical components. At my batt. using a multimeter I get 14.5V, but at the ECU i only get 12.9V.

My car takes forever to start. Its like it doesnt get fuel until it cranks over for about 8 seconds. Could this have to do with the voltage? I see something called Port Injector opening time VS Voltage in my software, im wondering if this needs to be changed?

Im having a problem with the O2 sensor again, it seems I've lost the rich side. It only goes from lean to Stoich, but never switched to rich, so the ECU kinda jumps the gun and floods the motor then pulls out a ton of fuel causing a lean surge. What a joke!

But it runs smoother than it ever has! I have a feeling the motor went together right this time, if nothing else did. Thanks everyone for the technical support, I wouldn't have done it without you guys; You know 3 years ago I didnt know what an alternator was? I had no idea what TBI or TPI was... I didnt even know how big the engine was in my 89RS. When I bought my 305TBI camaro i thought it was the fastest greatest thing ever, little did i know when I came to this site for the first time what I would wind up doing!

 

now time for some

 

well its running way better now. I used my auto tuner to get most of the map straightened out.

Still have the starting problem though. anyone have an idea on what that could be? I did a little more testing, and it appears it takes about 8 cranks of the engine for it to start getting fuel from the injectors. then it fires right up and runs right.

this occurs whether cold or hot, although cold starting seems to be easier but i think thats just because the engine turns over quicker when its colder. less heat soak i guess...