b21ft build (prelim, dumb questions)

So, the time has come -- a b21ft potential build

perhaps a financial mistake......

The rundown:

motor pull. i don't wanna take the trans with the block, just to make working in a driveway a little easier. i'll unbolt the bellhousing and starter, and once its out, the flywheel -- missing anything other details? where are the ideal mounting points for the motor (for the hoist)?

overbore and head work.

Guys at AMS machine supply recommended bore, and i don't disagree. huge lip at the start of the combustion chamber (my fingernail easily catches) as well as some corrosion that needs to be addressed.

Pistons? I'd like to preserve the low scr nature of the b21ft, just cause i like lots and lots of boost, and wouldn't mind some more.

Rods. Would it be safe to assume that i wouldn't have a problem running the m rods? the guys at the shop suggested getting forged rods (i know there's some disagreement around here that m rods are forged, but lets just say they are for the sake of argument), but that seems unnecessary (assuming they're in good condition) and a little too expensive, as i'm already going to dig a little deep into my budget for this.

Head work. Head mill -- not a big deal. Valve corrosion? What the ****? Teeny spots of rust and gunk on cyl. 2&3 valves. What to do about that? Attempt to clean it myself or...? Guys at the shop also suggested a valve job, $400. I about **** myself. I wanna avoid that at pretty much all costs, so if I need to get a junkyard head for like $50 i'd rather spend that kind of money.

Now.... considering all that.....

Do I do it? Or do I go to a upull (thanks bobxyz) and just get a junkyard motor?

If I go through with the build, based on the sage advice from the volvo gods, i'll maybe post a thread about the actual build and we can all cringe at a kid putting together an engine for the first time thanks for reading!

Did it run before you pulled the head?

I rebuilt my B21FT ~4 years ago. It was a quality rebuild - new pistons, oil pump, hoses, valve job, squirters, etc. OE Volvo, Mahle, Melling, Elring, BMW parts. I've never added up all the costs but, if it had gone smoothly, I think it was ~$1000 in machining and ~$1300 in parts.

If you're serious, you should read up on tight squish/quench and pay the extra $ to the shop for a trial assembly to get the deck height exactly where you want it. Or get them to do a minimal deck resurface, measure it yourself [I have the bridge gauge], and then tell them how much extra to take off on a 2nd pass.

Before starting, check with hiperf to make sure that you can still get B21FT 2nd OS pistons from Europe. If not, it's a non-starter.

I suggested finding a good B230FT instead of the B21FT because there's a better chance that a mild rebuild would be enough (reuse the pistons, new rings, freshen up the cyls, maybe the cranks is OK as is). The B21FTs are all pretty high mileage now. If you get lucky, you might find a low mileage B230FT with factory squirters.

If you go the B21FT route, I have a marked up factory rebuild guide with all the bad metric-to-english measurements corrected.

For a Shakespearean comedy/tragedy of another kid putting together a B21FT, read this lengthy post (Stealthfti - your wisdom lives on, RIP):
http://forums.turbobricks.com/showthread.php?t=25895

The b21ft rods are forged... heavy but forged. I didn't break mine but they did ultimately become a bit bendy... (granted that was 30psi with a 75 shot and the alternator bolt came out and the voltage dropped to 10v which leaned the motor out...to something like 15:1 down the track...) the b21ft pistons were all fine but they were all a bit lower in the cylinder after that.

Just remember that even built motors can still break. As a founding member of the cheap-ass club, I'm all in favor of replacing the broken part with a minimum of expenditure and getting back out there.

all Volvo red block rods are forged.

If you are going to build a b21ft. I would get longer h beams and pistons with a shorter skirt.

Stock rods and pistons are heavy

chronicrhythm said:

Did it run before you pulled the head?

Click to expand...

Yes, well enough, though not perfectly.

bobxyz said:

I rebuilt my B21FT ~4 years ago. It was a quality rebuild - new pistons, oil pump, hoses, valve job, squirters, etc. OE Volvo, Mahle, Melling, Elring, BMW parts. I've never added up all the costs but, if it had gone smoothly, I think it was ~$1000 in machining and ~$1300 in parts.

If you're serious, you should read up on tight squish/quench and pay the extra $ to the shop for a trial assembly to get the deck height exactly where you want it. Or get them to do a minimal deck resurface, measure it yourself [I have the bridge gauge], and then tell them how much extra to take off on a 2nd pass.

Before starting, check with hiperf to make sure that you can still get B21FT 2nd OS pistons from Europe. If not, it's a non-starter.

I suggested finding a good B230FT instead of the B21FT because there's a better chance that a mild rebuild would be enough (reuse the pistons, new rings, freshen up the cyls, maybe the cranks is OK as is). The B21FTs are all pretty high mileage now. If you get lucky, you might find a low mileage B230FT with factory squirters.

If you go the B21FT route, I have a marked up factory rebuild guide with all the bad metric-to-english measurements corrected.

For a Shakespearean comedy/tragedy of another kid putting together a B21FT, read this lengthy post (Stealthfti - your wisdom lives on, RIP):
http://forums.turbobricks.com/showthread.php?t=25895

Click to expand...

I think it's a no go for the 2.1. Hiperf sent a link for Skandix, and the pistons have been discontinued. A bit of a shame, I really liked this motor :/. My first thought is "just get it bored out to a b230 spec!" but why not just a 2.3 instead? I do like the overhead that b230's have, readily available parts (like yoshifab's rods and forged pistons that seem easy to get). Financially, it makes little sense now to drop a grand+ on, like you said, a high mile b21 when I could be spending the same money on a nice b230 with good internals. Thanks for your help, and that thread was both enlightening and disheartening. Again, a million thanks for your advice, dunno where I'd be without it -- probably with a car that doesn't run and empty pockets

740atl said:

The b21ft rods are forged... heavy but forged. I didn't break mine but they did ultimately become a bit bendy... (granted that was 30psi with a 75 shot and the alternator bolt came out and the voltage dropped to 10v which leaned the motor out...to something like 15:1 down the track...) the b21ft pistons were all fine but they were all a bit lower in the cylinder after that.

Just remember that even built motors can still break. As a founding member of the cheap-ass club, I'm all in favor of replacing the broken part with a minimum of expenditure and getting back out there.

Click to expand...

Beautiful... I love seeing thrashed volvo gear I can't imagine what 30psi feels like in a brick... what kind of turbo were you running?

John V can get you custom pistons and rods for the 2.1. I got a set of Wiseco roller wave pistons for a B21 from RSI right before they went out of business, I'll see if I can find the data sheet with the part numbers on it, you should be able to get the same pistons directly or through a distributor.

VB242 said:

John V can get you custom pistons and rods for the 2.1. I got a set of Wiseco roller wave pistons for a B21 from RSI right before they went out of business, I'll see if I can find the data sheet with the part numbers on it, you should be able to get the same pistons directly or through a distributor.

Click to expand...

This has piqued my interest -- if you wouldn't mind, and if it doesn't take up too much of your time, I'd love to get a copy of your spec sheet. Would definitely help me with the fellas at AMS to get everything sorted. I'll PM John V if you think that's alright, and thanks for your suggestions

There's a bit of info on the custom pistons here: http://forums.turbobricks.com/showthread.php?t=322850

The factory M rods weight a couple tons apiece - the M is for Massive chunk of iron, and it's really impressive that anyone was able to bend one. The factory pistons are OK, but going custom with custom rods should save a pound or more for each pair. Do you have a manual or auto trans?

makebrickgovroom said:

This has piqued my interest -- if you wouldn't mind, and if it doesn't take up too much of your time, I'd love to get a copy of your spec sheet. Would definitely help me with the fellas at AMS to get everything sorted. I'll PM John V if you think that's alright, and thanks for your suggestions

Click to expand...

Here's the Wiseco piston specs that uses the M- rods you already have. I was running 25psi on this setup until I had a fuel pump failure that destroyed the motor.


I would take a leak, have a good supply of your favorite beverage and schedule 2-3 hours and give John V a call.

bobxyz said:

There's a bit of info on the custom pistons here: http://forums.turbobricks.com/showthread.php?t=322850

The factory M rods weight a couple tons apiece - the M is for Massive chunk of iron, and it's really impressive that anyone was able to bend one. The factory pistons are OK, but going custom with custom rods should save a pound or more for each pair. Do you have a manual or auto trans?

Click to expand...

God, good thread. Seems like John V is the preferred recourse for figuring out the pistons. I have a lot to learn, but I know some things for certain at this point:

If I stick with the 2.1:
- Low comp, idiot buffer, more boost, less worry
- PERHAPS custom rods. Everything price wise is coming out a little price-r than I expected, it's a shame that I seemed to have missed out on the "golden age" of aftermarket performance goodies for these cars if it's in the budget it'll be a go

If I can get my hands on a good 2.3 block:
- Yoshifab hbeams
- Yoshifab pistons (16v clearance would be....... so nice. so tempting. the things i would do for a well done 16v conversion....)

It's an m46, which is hilarious to me. Can't believe I haven't blow in up yet (it'll obviously be the next thing to blow up if I'm not particularly stupid with everything else in the next month or two). I'm planning to, eventually, figure out a trans swap. i've been transitioning my attention from the tried-and-true wct5 to the cd009. interesting proposition to have a modern 6 speed in a brick. Of course, if I go that route (gonna have to at some point), lighter rods would make sense, along with a lighter flywheel (they make those for these cars??)

I have the thread for my 2.3 block search up as well, and I saw you replied to it recently -- I'm trying my options, just so I'm not high and dry if plans with the current motor don't pan out. I'll absolutely give swedish a call, I was really impressed with their work before I became more mechanically inclined and started doing a majority of the maintenance stuff.


Still have yet to pull the block from ol' dolly (need to figure out a hoist, stand, and some other not-so-fun logistical stuff), but I've got it 90% there. Just got the accessory bracket off, next thing to tackle is the alternator which shouldn't take more than half an hour tomorrow. Hopefully in the next week or 2 i'll have it on its way up to fort collins, if things start to materialize for it.

Sorry for the salad, when I'm not working or otherwise preoccupied I spend most of my freetime ruminating over these things, and I take that pent up obsessive volvo-think to the board. I do worry sometimes that my verbal diarrhea gives me a... reputation here. Thanks a million, always, for your sage advice and help!

VB242 said:

Here's the Wiseco piston specs that uses the M- rods you already have. I was running 25psi on this setup until I had a fuel pump failure that destroyed the motor.

I would take a leak, have a good supply of your favorite beverage and schedule 2-3 hours and give John V a call.

Click to expand...

Hell yea!!! Thanks a ton, I'll forward this to the guys at AMS and see what they have to say

I'd be surprised if any reputable machine shop would start work without having all the key parts in hand. Initially, they should be able to look at and measure the block to make sure that the cylinders will clean up at 1st oversize (+0.5mm) or 2nd oversize (+1mm), and that there are no glaring problems.

If you can use it, I have an extra B21FT crank, and a set of 175K mile pistons in the garage. I also have my original 350K mile engine, but I'm hanging onto it just in case something goes very wrong with the rebuilt one.

bobxyz said:

I'd be surprised if any reputable machine shop would start work without having all the key parts in hand. Initially, they should be able to look at and measure the block to make sure that the cylinders will clean up at 1st oversize (+0.5mm) or 2nd oversize (+1mm), and that there are no glaring problems.

If you can use it, I have an extra B21FT crank, and a set of 175K mile pistons in the garage. I also have my original 350K mile engine, but I'm hanging onto it just in case something goes very wrong with the rebuilt one.

Click to expand...

Yessir, AMS won't start work until they've done a thorough check over. I'm assuming I'll order the pistons through them (making a big assumption that the block's ok) along the line of VB242's specs (probably with some minor differences). I was planning to get the block out this weekend, but no luck, though I'm close -- unbolting the bellhousing and starter is pretty much the last big ticket before I need to figure out the hoist situation.

Here's a question for ya: when you did your rebuild, where did you mount the hoist on the block? I'm thinking of either the passenger side motor mount (with a hook) and something further back on the driver's side (maybe a big ol' bolt somwhere?), or, conversely, an accessory bracket bolt and somewhere near the bellhousing on the passenger side. I can't find much info online, and I don't wanna do anything stupid with the chain, or risk dropping the block back into the car (makes me cringe just thinking about it).

Also -- unbolt the flywheel, yay or nay? I'm not leaving much of anything on the block save for the metal back plate behind the crank and intermediate pullies, just dunno if it's good practice to remove as much as I can for the machine shop.

Honestly, just for posterity's sake, I may take your offer on the crank. I have no idea what the condition of the internals are, save for the pistons, on this block. It's supposedly "low-mileage" (i asked the mechanic whom i bought it from, he said he remembers somewhere around ~160k), but a lot can happen in those miles, especially if its true that it was in two totaled vehicles before it made its way to me from Georgia. If the guys over at AMS say it needs a regrind, we can talk more about what you're looking to get for it

If you want some pistons for your backup b21, i have a set of the bigger D/E pistons in pretty good shape (granted, they're still in the block, lol) on top of a bunch of other **** you could use depending on your interest.

Hope your weekend was good!
Henry

OH, something I've been reading about: b21a pistons in a b21ft. Seems like a good way to get higher comp (at a lower price, too, my god), though I'm ultimately worried if this would take away from the added benefit of these engines being non-interference, as another idiot buffer. What's your opinion? The cometic hg I have on order isn't too squishy, as I was assuming some shaving was to be done on the head (0.046 squished if that helps, as close to stock as I felt comfortable with), so I don't know what that effect that may or may not have.

There should be lifting brackets on the back of the intake manifold and on the front thermostat housing. There's also one on the exhaust side around #3.



If you use a leveler, it needs to go in front of the rear bracket, or else it will bump into the bulkhead.

If you don't have an engine hoist, go find one off craigslist for $100 - $150. Before buying it, make sure that the arm doesn't sag when you hang on it after pumping it up to horizontal. You can always resell it for about the same $$$ when you're done.

A leveler (harbor freight $40) helps, but isn't essential if you're young, strong, and have some help. With the earlier 240s, you can unbolt the top radiator support / hood latch panel to get lots of extra room. It's spot welded in later 240s.

The crank and "D" pistons are free for local pickup - I'll never use them.

For the B21A pistons, I stayed away from them because they'll increase the static compression a lot compared to the deep dish B21FT's. It depends how comfortable you are with MS tuning and a ~9.5 to 1 SCR. It will give a bit better puttering-around-town performance but may limit max boost due to early knock issues. IDK.

"With the earlier 240s, you can unbolt the top radiator support / hood latch panel to get lots of extra room. It's spot welded in later 240s"

I drilled the spots out & use bolts in their place.
It does make things a lot easier, especially if you leave the head on while taking the engine out.
Tim

bobxyz said:

There should be lifting brackets on the back of the intake manifold and on the front thermostat housing. There's also one on the exhaust side around #3.

If you use a leveler, it needs to go in front of the rear bracket, or else it will bump into the bulkhead.

If you don't have an engine hoist, go find one off craigslist for $100 - $150. Before buying it, make sure that the arm doesn't sag when you hang on it after pumping it up to horizontal. You can always resell it for about the same $$$ when you're done.

A leveler (harbor freight $40) helps, but isn't essential if you're young, strong, and have some help. With the earlier 240s, you can unbolt the top radiator support / hood latch panel to get lots of extra room. It's spot welded in later 240s.

The crank and "D" pistons are free for local pickup - I'll never use them.

For the B21A pistons, I stayed away from them because they'll increase the static compression a lot compared to the deep dish B21FT's. It depends how comfortable you are with MS tuning and a ~9.5 to 1 SCR. It will give a bit better puttering-around-town performance but may limit max boost due to early knock issues. IDK.

Click to expand...

Good looking motor!!! Craigslist prices have been jacked recently -- I've been on the search for a minute, and for around ~150 i may just consider doing a day rental when im not super busy just for the ease. i think a buddy of a buddy may have one (he did an engine swap on his slammed tacoma and slapped a 55trim on it recently), though that's uncertain, but that'd be the cheapest and quickest option all else fails, i'll get some Pittsburgh pos and call it a day.

Big pisser is that the block is basically stripped down to, well, the block -- nothing's on there except for... the starter and alternator. Oh, and the pcv box. Would it be recommendable to just stick the head back on (with the blown hg), and hoist it from there? I'm not planning on taking the trans with it (too much under-car work for me to feel comfortable in the driveway, seems easier to just nab the block). I was planning on taking the block forwards at level (before the sump hits the subframe) to get the input shaft out, to the best of my ability. I might have to get creative with how I get 'er out.

Thanks for the tips and the help!

K9 240 said:

"With the earlier 240s, you can unbolt the top radiator support / hood latch panel to get lots of extra room. It's spot welded in later 240s"

I drilled the spots out & use bolts in their place.
It does make things a lot easier, especially if you leave the head on while taking the engine out.
Tim

Click to expand...

Found that out the hard way trying to source replacement for my upper core support :/ i'll take it out before the motor comes out, i need a new one anyway (blew out a rivet and a screw hole overtorquing a bolt, jb weld has proved ineffective). Thanks for your help and suggestions!

Oh, the block is already stripped down in the car, that changes things.

First off, you want something over the top of the block to protect it from dropped tools. I'd use the head gasket to cut a scrap board to length and drill a couple holes, then bolt the board on, over the head gasket - you'll need a couple 2x4 chunks to take up the extra head bolt length. Alternately, a couple layers of cardboard taped on well would be ok.

Before covering it over, make sure the surfaces are oiled to prevent rust. It's not really a problem in CO, but you can still get some surface rust on dry surfaces if it's humid out.

To lift the block, you want to find a couple bolt holes near front and back, close to the top. Maybe the distributor hold down bolt and the coolant tube bolt on the back of the block. Run the bolts through the lift chain links, with a couple washers as needed.

I've not removed a volvo engine without the tranny attached. Do some searching for the tricks involved (something about a stack of socket extensions to get to the starter bolt).

You're probably OK taking the engine to the shop as is (oil drained). You could remove the pan, pull the oil pump and PCV drain tube, and put the pan back on with just a couple bolts. If you have an impact gun, you can remove the flywheel/clutch/pressure plate and bring them to the shop separately to see if they need to be resurfaced. An old tire works well for transport.

Are you going to install squirters? (See the long stickied squirterizational... thread) If so, you should tear the block down and drill/surface/tap for the squirters before bringing it to the machine shop. That way, any metal shavings that get into the oil passages will be flushed out when the shop removes the plugs for block cleaning.

bobxyz said:

Oh, the block is already stripped down in the car, that changes things.

First off, you want something over the top of the block to protect it from dropped tools. I'd use the head gasket to cut a scrap board to length and drill a couple holes, then bolt the board on, over the head gasket - you'll need a couple 2x4 chunks to take up the extra head bolt length. Alternately, a couple layers of cardboard taped on well would be ok.

Before covering it over, make sure the surfaces are oiled to prevent rust. It's not really a problem in CO, but you can still get some surface rust on dry surfaces if it's humid out.

To lift the block, you want to find a couple bolt holes near front and back, close to the top. Maybe the distributor hold down bolt and the coolant tube bolt on the back of the block. Run the bolts through the lift chain links, with a couple washers as needed.

I've not removed a volvo engine without the tranny attached. Do some searching for the tricks involved (something about a stack of socket extensions to get to the starter bolt).

You're probably OK taking the engine to the shop as is (oil drained). You could remove the pan, pull the oil pump and PCV drain tube, and put the pan back on with just a couple bolts. If you have an impact gun, you can remove the flywheel/clutch/pressure plate and bring them to the shop separately to see if they need to be resurfaced. An old tire works well for transport.

Are you going to install squirters? (See the long stickied squirterizational... thread) If so, you should tear the block down and drill/surface/tap for the squirters before bringing it to the machine shop. That way, any metal shavings that get into the oil passages will be flushed out when the shop removes the plugs for block cleaning.

Click to expand...

Wonderful info -- your help is positively invaluable. Oil squirters seem a little out of my league (for now ), but that seems like a fun mod for the future. Hopefully soon I can actually get this thing on its way to AMS!!