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Building a B21FT from the ground up

Wow, lots to catch up on! GREAT! Okay, here I go:

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The Aspirator said:
Thanks! This is getting me all excited. I just wish I had this kind of time and money to spend into a rebuild of my motor! Sometimes I feel like it's a ticking timebomb....:omg: .

John
HAHAHAHAHA, I just noticed that I posted this up top. Well guess what? The timebomb finally blew:
http://www.vipinfoservices.com/john/images/myB230block01.jpg
Due to that I threw a rod bearing. So now I get to build up a new motor of my own too!

***
stealth said:
One other thing: are you using an old style exhaust manifold? or a 90+ manifold?
I've read your Pbase site a few times, and understand your thoughts on this. Currently we're just using the pre-90 manifold. I think this will be something that we won't worry about right now, but will probably upgrade with later. Things like the 90+ manifold, bigger intercooler (NPR), bigger injectors, etc. Those are all bolt ons per-say. This round of work and money spent needs to go towards the shortblock itself, and whatever is needed to make it as powerful as possible and as strong as is reasonably possible. The rest can be dealt with later.
zombiewoof said:
Whay not find a B23 or B230 shortblock? I always assumed people built B21s because it's what they had (and weren't rebuilding) or for racing regs. Why not go with the larger displacement?
We're using a B21 platform because that's what we have available. Sure we could go out and find a '94 block with oil squirters built in, but in my mind that is money that we don't need to be spending at the moment. From what I've been reading, B21's can be nasty powerful if you build them right, especially when you've got a turbo involved. Sure, more displacement = more power, but for our goals of this buildup, the 2.1L should be plenty. Though for my car, there's no way I'm downgrading to a 2.1L, it's always going to be 2.3L or more.
stealth said:
...the used pistons need to be CLEAN. not for the aesthetics of 'lookin' purty'; but for the purposes of having CLEAN ring grooves. If the pistons are not already clean; the MS can clean them up so that they look like new. And that cleaning will clean the ring grooves without damage. I do not use ring groove scrapers. The potential for damage to the grooves is so great as to be almost a certainty.
The pistons are currently spotless. Matt did a very good job of beadblasting them, so they're very clean on the outside. BUT, the ring grooves are still a little bit dirty. THANK YOU for advising against scraping the grooves out. Knowing me I would have spent a good hour with a small screwdriver or pocketknife scraping all the gunk out. Now I'll just let the machine shop handle it.

stealth said:
Who supplies the freeze plugs and intermediate shaft bearings is for you to work out with your MS. I have my MS install the freeze plugs. I could do it; but I am lazy. I install the oil gallery plugs later...after I brush out and thoroughly wash and flush the block and oil passages. That is definitely MY job; and my responsibility to make sure that those are clean. And it is my job to make sure that there are no restrictions to oil flow through the passages.
For the oil galleys, do you just use long metal pipe cleaners? Are the galleys straight? How do you wash it out afterwards, just with the garden hose, or do you have your own solvent parts washer? I don't have one, so we'll have to figure something out.

***

Camshaft choice and absolute redline:
We have 4 different cams available to use for this motor. A-cam, B-cam, K-cam, T-cam. Going by what you said above, how a high lift cam might produce interference, I'm assuming that the K-cam is out of the question. I do like it and the way it reacts, but if we can tailor this motor to a different camshaft then that's cool too! Humm, I just had a though, would you want to shim that cam loosely then to compensate a bit for interference? Or is that kinda counterproductive?

Camshaft choice would undoubtedly have something to do with absolute redline.... right?

T-cam, I dunno, everybody says they're ghey for performance use and that they die off in the higher revs. This is a 17 yr old (almost 18) kid we're dealing with here, he likes to rev, keep that in mind. Although with Megasquirt and Spark, it's super easy for me to put a nasty rev limiter at whatever is needed, so yes, we need to decide that aspect right now.

For now I don't think we'll touch the valve springs, or any part of the head actually (cept the cam). With the stock valve springs it obviously won't rev to 8500rpm efficiently, but what will they do? Would a 7000 RPM redline be too much to ask? I set mine to 6600 the other night with my K-cam 6* advanced and B230F+T, it pulled hard all the way. I really don't know what to expect from this engine buildup. Stealth, I take it that you do know what to expect from it, and I'd like to hear your recommendation.


Doug said:
Skip oringing, just use a Copper sprayed Elring gasket. Remeber, oringing keeps the head gasket from acting like a FUSE, this means possible boom big way. Plus, you'll save money.
Well, my headgasket blew a few days ago, thinned out my oil, and spun a rod bearing. I think it blew solely because of too much clyinder pressures (18psi from Holset, 9.8:1 compression) because there was no pinging and A/F ratios were happy. This blown headgasket f.ucked up my shortblock, and I'm kinda pissed about it. I do NOT want to have this happen to Erik's engine. It will be tuned very well and eventually get knock sensor ignition retard, so detonation will not be a huge issue. People like to use the HG as a fuse to prevent what.... detonation from squashing a rod on a poorly tuned K-jet car, right? Well if detonation is prevented, what's the harm in O-ringing? Just my oppinion, please argue at will.

I'll write more soon, just wanted to submit this before I loose it all from some stupid mistake.

John
 
1 month old headgasket, I forget if it was Elring or not. I got it from FCPgroton, and from them I've recieved elrings and other brands. It's still in my trunk, so I might be able to check it still, though it stuck to the head and block alot during removal.

I torqued it to 45ft/lbs, then 90* on every bolt. This is what the manual suggested and what I've read on the board many times, so this is what I did. Are you saying that you're giving it 45ft/lbs then another 180* turn?

John
 
Hey bud, sorry to hear about the motor. We almost started a pool at work, predicting how many weeks it'd take to let go. :) If ya need a cheap interim motor you could probably get a hook up.


Just thought I'd add some small, relatively insignificant detail to stealth's post re: clean used pistons. Cleaning them oil return holes in the rings grooves is crucial- but one nice and cheap and easy thing to do is to drill em out to about 3mm.

Oh also I was wondering what the concern is re: the k making the car an interference motor? unless you plan on breaking t-belts it's sort of a non-issue isn't it?

Re revlimit: On a car with new early style valvesprings I would wind it to 7000 without major worries. Even a straight up k cam is prettly close to dead by then anyways. Besides with stock manifolds it won't be interested in moving air past that point also regardless of cam. Anything past that is just the proverbial wang measuring BS unless you're talking full race and a scary cam, sheetmetal intake, tubular header, 4.10 or shorter diff, etc.


Re: headgaskets- hmmm. It generally takes a good while for a blown hg to eat and engine from coolant in the oil, unless you mean that your hg was blown and you drove for a manner of days or even weeks without fixing it. And to load up the oil that fast it'd be blowing out the breather and etc everywhere. It'd have to be a spectacular blowout. I'd suspect the same detonation that killed the hg spun the bearing but that's just my guess.
The headgasket fuse idea assumes the car will be tuned to never see detonation, just like you buy life insurance even if you don't actually plan on dying anytime soon. But, you get insurance becuase sh!t happens. It just does. Your fuel pump relay takes a dump, a vac line to the fuel pressure reg ruptures, who knows? But the idea is it's better to lose a headgasket (and you will suspect it right away after something catastrophic happens) and then fix it on the spot than have something screw up and bend a rod. A knock retard ignition will not save you if for some reason you have a major fuel delivery at high load. The save grandmas who put the wrong gas in on the way back from IGA. ;-)

Oh and also, i am of the opinion that you cannot actually say your engine is tuned "right" and is "detonation free" until it is set on a dyno and everything is mapped and plotted and tested with a 4 gas or better. Sure that will earn me some scoffing from the peanut gallery... :)

on edit: just saw your latest- if you want some early headbolts we have a big bucket of 'em.
 
Hey Ken, thanks for the comments. I've been meaning to PM you about my car situation but haven't gotten around to it. Here's what happened: I took one run at the dragstrip, everything went alright. A while later I took another run, drove alright. But when I was getting my timeslip I engulfed the car with white smoke from the tailpipe. Drove for one minute and parked it. Didn't think much about it, until I started it up about an hour later. Tons more white smoke. No coolant. Totally milky oil, just nasty green color (mobil 1 oil, about a month old). Oil was coming out the flame trap hose a little bit (yes, I finally put a flame trap hose on). I put my hand over the coolant tank with the engine running and felt it pressurize quickly. It idled for maybe 5 or 10 minutes, then we drove it to a Canadian Tire parking lot a few minutes away to park it for the night, cause I sure as hell wasn't going to drive it home with the oil like that. Next day my brother and I came with a new headgasket, swapped it in within a few hours, in the parking lot, and started it up. KNOCK KNOCK KNOCK KNOCK KNOCK. You know, that blood curdling, sickening noise. It was loud. It wasn't there the night before. I'm wondering if the rod bearings got a bit of surface rust on them or something, cause I noticed that my camshaft did, just from sitting overnight. Ohh well, after that I knew it was screwed, and I HAD to drive it the 1.5 hours back home to Vancouver. So here it sits. The knocking actually got much MUCH quieter once I got home, almost in audible. Weird, but whatever. I'll PM you Ken with some solution ideas, cause I've already got a few that I'd like to run by ya.

Ohh, and I certainly did notice that huge bucket of old style headbolts at your shop. I might just have to hit you up for a set or two of those.

So that's what happened to me last weekend!

John
 
What I do is follow the manual, AFTER I've torqued them all, I give them another 90* (not 180 in one blast). This worked fine on my preoringing days.

Im sorry, if you were running good AFR and no Knock theres no reason your motor should have let loose. Me thinks something else was going on there (ie, it was ready to go) combined with possibly a partially warped head or cheap head gasket.
 
Maybe it was just a crappy headgasket, now that I think about it I doubt it was an elring.

But Doug, why are you advising against O-ringing on Eriks B21FT? You're O-ringed, and this motor buildup will be similar to yours, and putting out less power. You haven't had any problems with the O-rings right? Do you feel that on your motor, you want the HG to be a fuse? Just trying to pick your brain bud ;-) .

John
 
another 90 degrees

Hey Doug,
how on earth do you build a tool with enough leverage to go another 90* after the initial 90*? I can barely get my headbolts to go the final 20* or so, even with a cheater bar on the breaker bar. I guess I need to go to the gym more often...
Also, how does it NOT shear the engine mounts or snap off the headbolts in the block?
Most curious,
JD
 
After the 45ft/lb initial torque, the extra 90* isn't too hard for me. I use a bike handlebar at the end of my breaker bar, but I still don't find it that difficult. Maybe it's just different on differen't vehicles? I've done about 4 or 5 head installs lately. I could probably squeeze another 90* out of it without breaking something, but I'd be worried about deforming the head or something like that.

John
 
The Aspirator said:
Maybe it was just a crappy headgasket, now that I think about it I doubt it was an elring.

But Doug, why are you advising against O-ringing on Eriks B21FT? You're O-ringed, and this motor buildup will be similar to yours, and putting out less power. You haven't had any problems with the O-rings right? Do you feel that on your motor, you want the HG to be a fuse? Just trying to pick your brain bud ;-) .

John

John, theres one reason. He's your brother? I don't know him... so I have no way of saying if he's going to be smart enough to let of when pinging ect.

Not to knock, just covering the bases. IF you think its safe to oring (like I said, think headgasket=fuse) then go for it. I really didn't have any real issues with using a copper sprayed elring (on a BCP head).

The extra 90*? Im just a muscle man I guess
 
John (and at the same time, Erik :wave:) this thread is shaping up to be fantastic, along the lines of Squish vs. Swirl. I can't wait to see what the end results are, and i wish i was keen enough to think of buiulding a motor for my senior project :rant:

when i get the time and money, i'll be starting a similar thread for building a b230 from the ground up, as thats what im planning (may end up being a b250 ;-)) for my next big project after the +T swap. keep up on the updates and great pics, and good luck with the MS
 
volvo-slyder said:
Maybe a newb question but can a b23 head be fitted onto a b21 block?just wanted to know because i can get a b23 head for 70$ from a friend :???:
Yeah, it'll fit just fine, but unless it's a 405 head you're waisting your time. Unless of course your cylinder head is in poor condition, or this new one is in extremely good condition. But the 405 is a good upgrade.

Doug, I hear ya, and appreciate your oppinion. He's a young whipper snapper, and definately not as car savvy as I am. He just helped me replace my headgasket, and has done his onw all by himself. He knows what pinging is, has heard it, and would probably be smart enough to get outta the gas if he heard it...... if he were listening for it. He's got a thumpin' sound system in it, so he won't always be listening for it. Good point! Thanks for helping me realize it. I think the copper sprayed Elring might just be the way to go for him. I don't think he'll be using a bigger turbo than his 60/63, at least not for a long while.

Now for MY new engine, I think I'm gonna O-ringing the sucka. I've got the big turbo, high boost, way high compression, and a good ear. Plus no stereo.

Billy, glad you're here to learn with us!

John
 
Hey Stealth, are you still around? I think you mentioned you were leaving for the salt flats on the 10th, and will be gone till the 20th or so?

If possible, I'd like to get just a few things wrapped up here so we can start doing some work while you're gone. I guess we'll just start doing things in order. Get all the parts tanked and magnafluxed, and basically just start talking to different machine shops till I find one that can hook me up.

John
 
John,

sometime over the weekend I will finish up what I want to suggest on the motor build.

TF
 
Thanks Tom. It certainly won't be finished in the next three weeks, but we hope to have a good start on it. I still have to take the time and teach all this to my brother!

*sidenote*
If I got a B23E for myself, it comes with 10:1 compression ratio. Say I wanted to drop the CR down a bit, to maybe 9.4ish, how would I do that and still keep a good squish? I'd assume mill the tops of the pistons down some, and deck the block. Obviously I remember everything you said above, so I'm not asking you to go over that again. But I remember in "Red Dragons" B23 stroker post you mentioned a concern for milling the tops of the pistons, something about not wanting the rings to sit too high on the pistons?

I know that there are some calculators out there that would tell me how much needs to be milled down, and also Matt Dupuis did a great writeup in this thread. Just wondered if there were any other aspects to it that I'm not aware of.

Thanks,

John
 
To drop compression ratio properly, you want to dish the pistons. However, the crown thickness of those flat top pistons are thinnest in the center part, where you'll be putting the dish. That's ALSO where the greatest concentration of heat will be. To get it down to 9.0:1, you've got to take out (just guessing here) a 2" circle, about 1/16" in depth. Ideally, you'd "reverse dome" the pistons, where the dish took on the same profile as the combustion chamber, to maximize squish. You probably wouldn't have to take out quite as deep of a cut, in that case. I believe the crown thickness is about .300", so if you're taking off .040" or less, I think it'll be alright, but there going to be even MORE sensitive to detonation damage afterwards, and they're already kinda soft in that department.
 
Hey, John - why don't you let me do up some sketches in AutoCAD this weekend and I'll get you a drawing to take to your machine shop, plus we'll be able to tell exacty how deep you want to go. I can do one for Eric's car if you like too, to get him down from 9.5-9.6:1 to 8.5:1 or so so he can run some boost without fear of pinging. What head is he using again?

I'll PDF the drawings once I'm done and send 'em to Dana for a place in the archives, and if someone else wants to do what you're doing, they can use 'em too.
 
Both the B21F and the B23E pistons are cast, correct? I just don't want either one to turn into Isaac's B23F, where his pistons broke at the ring lands.

Erik is using a 398 head, everything is beadblasted and clean, and all the valves are lapped pretty good.

The more I think about it, maybe Erik should have slightly lower compression in his engine...? Somewhere between 8.5 and 9.0 would probably work great, especially if we can get a tight squish in there. Now if pistons are dished in the middle, how does that effect squish? And if they're "reverse domed" that would probably enhance squish more right?

AutoCAD drawings would be awesome, though I don't have a CAD program to read them with. One of my good friends has a milling machine in his shop. It has a digital display that tells exactly how deep you're going to the millionth of an inch or something... So if I knew the exact dimentions and depth that needs to be milled off, I'm sure we could tackle it there. For free no less, and free is good.

Before milling, we will definately try and measure the thickness of the crowns on these pistons. So lets say they are .300" thick, and we need to take off a 2" circle at 1/16" depth, that's roughly 20% material taken off. They should still be plenty strong with 80% left eh?

One last question. Instead of taking out a 2" circle at 1/16" depth, why not just take a whole slice off the top of like 1/32"?? That way they'd still be flat top pistons, it'd be easier to mill, and they'd be thicker. Just a thought.

John
 
John, i'm pretty sure that "reverse domed" pistons are the same as "dished" ones.

from my understanding, squish is the distance from the piston top to the head (i.e wherever they are closest, like around the outside of the piston to the side of the combustion chamber) so dishing the piston doesnt affect squish distance. i may be worng about this, but thats just how i interpreted the data in Squish vs Swirl.

i think the reason you dont wanna remove a whole layer (a slice if you will) from the piston is because it moves the rings closer to the chamber, which ins't good

i think it would be good to run less compression on your brother's car bc that means 2 things: he can ultimately run more boost, and also it has greater ping resistance until he boosts it too much. so its safer for someone who likes to listen to their stereo more than their engine ;-)
 
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