That's not the cylinder number, that's the goofy thing. It's just a number 2 in the exhaust port, for whatever reason. Most of the shots of the clean heads were of the #6 chamber & ports.

There's a lip maybe 2/3 of the way around behind the seat. It sticks up off the port floor maybe 1/16" - 3/32". The only place the throat approaches the port wall is against the right side (from the piston's P.O.V.)

Without having measured it, I'd say that the diameter of the throat and the diameter of the hole at the manifold flange are about the same, but there's a Pulsair bump blocking part of the port exit, and if I had a gun to my head I'd say that the cross-section of the port right around the valve guide area is GREATER than the cross-section of the throat or the port exit. Kind of opposite to what you want: smallest cross-section right at the throat, gradually expanding towards the header.

The exhaust gas squeezes past the valve and enters a room that's blocked off to the right and down by the guide but opens up HUGE to the left and back the way it came. Then it kind of squeezes back together and bumps past the guide, over the Pulsair junk, and out a too-small hole, into a manifold that you'll have to see to get the rest of the power-robbing picture.

I'd have to cut apart one of these heads to get a cross-sectional picture, though you can see quite a bit of what's going on through the coolant holes. I would say that there's a ton of meat around the guides, but that's just enlarging the room even further. Yes, you've got to slow the air down to make it bend around the corner, but that area is after the gas is supposed to have turned, which isn't going to help.

I think I can get most of the throat blended into the port walls fairly smoothly, and can get a "SOHC-quality" radius to the short side, but the short side is probably 1/3 - 1/2 of the perimeter around the throat, compared to at most 1/4 of an SOHC exhaust port. If I had my 'druthers, I'd be adding material to the port just past the throat, and reshaping the walls slightly. Ideally there'd be some added to the floor as well, but if wishes were fishes...

I wonder what the 24v version of these heads looks like, and wonder why it only made 30 horsepower more?

Lordy, hadn't seen this thread:

http://forums.turbobricks.com/showthrea ... 684&page=1

He's got a picture linked, where you can see how bad the intake port is on the F engine. I guess the pistons are domed? This guy cut them down to lower compression. I thought they were flat topped...

Damn.

I've found a drawing. Wow, that SSR is
Just some stuff I've found...
http://www.upload.ee/image/64443/HPIM3365.JPG
http://www.upload.ee/image/64444/HPIM3366.JPG
http://www.upload.ee/image/68193/HPIM3456.JPG
http://www.upload.ee/image/61346/HPIM3330.JPG

That does help explain some of the thirst.

I had a B280 car and loved that it was generally reliable and smooth. Hated that it was a little hard to track down good parts for even though it didn't need much and that it got absolutely terrible fuel econ for not having a whole lot of power.

I guess the big ideas here are:
Expensive to rebuild, so ideally find a decent bottom end and re-condition existing.
Combine best of B280E and eagle/monaco
Get the SCR up a bit.
DO ANYTHING better than those exhaust ports and manifolds...never seen such a clean turd...well done.

The manifolds, if one is going to say anything nice about them, probably do fit a bunch of apps and were inexpensive to manufacture and don't seem to crack, warp, or blow gaskets that I can tell. That's nice. They got something right. Other than that, flow and efficiency wise, they really are something incredible for a something resembling a modern FI alum/alum engine.

I'd be impressed if one could make a ~200 crank HP at sea level with good, usable power and torque reliably as well as being reasonably efficient runner with what is available economically. Seems doable while still keeping the car pleasant to drive.

Once I started adding up the machine work necessary to completely rebuild one properly, it was getting pretty daunting. I don't think they intended for you to repair one of these if it had any major issue that affected the bottom end or sleeves and a head gasket would be pushing it. Truth be told, I'd probably find a running parts car monaco/premier/760 for even an HG that was just a minor "whoops" I think unless I had good reason to believe the bottom end was a survivor of that.

That's some crazy stuff there.
I gather one doesn't want the DOHC version reliability wise. Better to stick with the existing I guess.

You see why I didn't post those pictures myself? LOL

What this guy's showing off is the F intake port. You can see why it's so bad, with that rampy swirly thing that he eventually cut right out to make it look somewhat like an E / EP intake port.

James, you're absolutely right - this thing was never meant to be rebuilt. If the head is warped, the green book says to replace it. If the crank is scored, the green book says to replace it. If the cylinders are worn, the green book says to replace it, as well as the corresponding piston/ring pack (which should never be mixed and matched, as they're matched at the factory). The block is not to be decked, the head is not to be skimmed, the crank is not to be cut. End of story.

The good news is that unless severely mistreated, the B280 should last a long, long time.

I also have to thank you for the timing chain set, James - I assume that was you.

If only I could find some E cams, or better. I tried emailing the guy from DMCUK and he was absolutely no help the first email, now he refuses to respond.

Oh well, it's really tempting to replicate what this dude on Tbrix did. Of all the rotten luck, why did I have to come across that thread?

Ya, I'd take the time to shrink them...but larger is better sort of. I like the photo of that port...it's like they decided to choke about 1/2 it off right in the bowl area. That's nuts - It looks like you can fix quite a bit of that and John Lane is sure that there is 30 hp choked in the manifold alone. I also like them for how disgusting the engine can get and still work. I'm not sure what some of the dimples and doo-dads are for in the combustion chamber and on the pistons - not much you can do about them anyway.

Careful cleaning and you should be fine with respect to the rest. I suppose the Volvo oil change interval of 12000 km (or some such) didn't help things - let hope the insides are better than that.

Now I'll go fix the pics.

Remember what it used to look like? I haven't finished them yet, but they're roughed in and smoothed over, and over the next little while I'll touch them up as needed. I don't know how much "polishing" I'll be doing, as I think it matters very little.











Like I said, not much to do to the intake, just a bit of cleaning. I didn't spend much time on these with a flap wheel. I will do more later but like the exhausts, I won't concern myself too much.





And some pix of the valves before I touch them up. Stock 45mm intakes, 38.5mm exhausts. Compare that to stock 44/35 for the B21/B23/B230 heads. I'll put a chamfer between the face and the margin on the exhausts, and will put a 30 degree chamfer where the lip is on the back of the intakes.

Looking good...I usually take the exhausts down to 320 grit with a roll. That's lots - what's up with that exhaust valve? Were they trying to create a plug for the port (almost serious here). That's a very wide base to the valve. Are you talking about doing some back cutting of the valve? I wonder if you could neck down the exhaust valve area in the radius area?

Funny stuff right here:

Eagle Premier / B280 exhaust valve versus B230FT (V6 on the right, and the bigger one):






Eagle Premier / B280 intake valve versus B230FT (V6 on the right, and the bigger one):






B280 intake versus exhaust length (intake on right):


B230 intake versus exhaust length (exhaust on right):


What's it all mean? Well, anyone who wants an upgraded exhaust valve for their OHC Redblock can start looking in the Mopar aisles, and you'll get 6 of them to boot. Same stem, different keepers but they might work with the redblock valve spring retainers. The overall length is not very different as you can see...

And the kicker is that Lawrence's 48/40mm redblock valves (that are .100" too long) might just work in the V6 heads! LOL, maybe next time around...

EP has hydrailic lifters and iron rocker arms IIRC. B280 has alum rockers and adjusters IIRC?

How does that all play out...I guess any valve stem is a valve stem an if it fits and the geometry is within the allowable range of the original intent, that is what matters.

I've seen people really muck up even a simple volvo SOHC 8V, which for all intents and purposes, is as simple as a valvetrain can really get.

That design reminds me of some crazy blend of hemi, BMW-esque "fly-cut" and Alfa-romeo (and many others) 164 with the shorty pushrods and lifters "sideways" (no joke!) in the OHC head.

I must be stodgy, but I have this (likely misguided) belief that one is allowed OHC or OHV+rocker arms, but not both. If you have OHC+rocker arms, you designed the engine with too many parts, more maintenance expense, more adjustment required, and worse longevity (valve guide/stem wear and more cam wear/worse revving come to mind). Worse yet, if it is a DOHC, probably no increase in power. I'm sure I will be flamed for this misguided belief without providing more supporting evidence, and it isn't like one design is somehow god's perfect solution. I'm just throwing it out there.

No doubt, one could counter that by saying:
Rocker arms allows possible easy valve adjust when needed
Compromise by having fewer cam lobes of valves, but getting some of the advantages of a DOHC
Less friction than a DOHC possibly (if not worse revving)
Fewer parts than a DOHC (well, valves anyway)
Good blend of efficiency and power when compared with simpler SOHC or OHV up to and beyond DOHC+multi-valve.

Problem is, the PRV doesn't really seem to grab the best of all of that very well until one re-combines it a bit.

That said, this quest for B280E+EP nice runner really is an interesting puzzle. And, my DD is an engine in a lot of ways exactly half way in-between a B280E and a B23F and OHC+rocker arms no less, though longer stroke/lower rod-stroke ratio on the bottom half then either more "under-square." This is a toyota 22re. Rocker arms, squish pad, fly cut head, timing chain, iron block, alum head. Makes about the same power as a B280, fuel econ of B23F. Pity it isn't as smooth as a six...oh well..its a basic truck. Now turn that frenchie V6 more into that! Poof! 180-200hp, lots of torque, 22mpg in a truck (still very slow...it is a heavy 4runner...slushbox NOT a realistic option for not fainting in the sight of hills with the trailer on or in 4wd). I'm going to have to make a couple revisions on it to make it do what I want in fairly similar fashion. Some parts aren't as bad, some parts worse. They got the intake pretty nice on both for torque. Big plenum, long runners, good distribution. Mine is a 2pc intake more like the earlier PRVs instead of the B280 nice big center plenum lovely thing.

I've found the stock valve sizes with the seating angles and depths altered within allowable range to be able to flow very well with the right port shaping without notable sacrifice to non-interference, power band, or use of non-stock parts in the SOHC 8V. Flame me some more!

Wat?

LOL, anyway, stodgy or not, the quest for power always requires replacement of some component for some other non-stock component at some point.

As far as the rocker arm thing, I could point out an example or two of successful versions of splayed valve SOHC heads, but I think you're saying "what's the point when a single component can do the work of all those rockers?" Remember DOHC needs lifters too, and shims, and much more machining (lifter bores, etc). Add to that the width of packaging in a Vee engine, the increased cost of maintanence (valve adjustments and more care needed when changing timing belts), and the inability to perform variable valve lift & duration without rockers, and you can see why manufacturers don't go the DOHC route ALL the time.

Don't get lost in the old stigma of pushrods either - lifters plus pushrods plus rockers can be made to work at high speeds, and from an inertial standpoint, direct acting rockers may even be lighter than a shimmed lifter bucket, when you remember that the heavy part of the rocker doesn't move as fast or as far as the valve.

Now, as to why the B280 makes such piss poor power and economy? I don't know why the designers chose some of the things they did, but they're smarter and better equipped than I am and I'm surely messing up their intent with all this grinding away at things. 50 hp/litre from a 2 valve engine was about the norm in the 70's/80's European world. Exceptionally hot engines may have gotten 60 or even 65, and 4 valves made about 70 hp/litre. By those standards, 150-170 hp from a mild 2.8 is pretty decent! Too bad for the PRV it was offered alongside a fairly bomb-proof, fairly large, mild-tuned turbocharged engine to be compared to.

The EP has hydraulic alloy rockers and the B280E has alloy mechanical. The B280F has different rockers, can't remember if they're alloy or iron. Valves are interchangable, and I'll be using the B280 cams/rockers on these EP heads. I don't know if one spring is different from the other, but with a 6000 RPM redline, I doubt it matters.

Anyway, back on topic: I think I've spent enough time messing with the grinder, so next step is to touch up the valves, clean things up, and send them off to get the valve seats touched up and to deck the heads a bit. Meanwhile, it will be on to the engine / tranny, and working towards adding a third pedal. Probably won't be starting that 'till after the holidays though...

Great progress by any measure. If you're brave, I'd still taper that valve backside a little. They are just forgings and then get ground to size. Good to know you have a source if they get tired or if they are no longer concentric. As long as that keeper is in the same spot - changing to another is no big deal.

As for the rockers debate - there are lots of engines of that time period that work just like this (Ford Pinto...the Euro one) and many others. I'm sure it was a matter of machining cost and a design that everyone understood.

As for that exhaust port and manifold -that is a crime against nature and should be punished.

I don't know what to do about the exhaust valves. I could cut them back but I'm guessing they're not 1 piece so I'm not sure what I'd be doing to the strength. I'm also not sure how well I will be able to shape them. I can (should) go get a proper radius tool to pull it off. It would maybe help low lift flow somewhat, and since max lift is under 3/8" one could say it's ALL low lift flow. I'm not sure it's worth the effort in this engine, though. I wonder if it's a way of curving the exhaust gas down into that awful port in some attempt at making them work?

All I was planning on doing to the intakes was to cut off that ramp, right where the back face transitions to the seat. That'll probably be the biggest improvement I can easily make to this side of things.

Hm, okay, fair enough. I suppose you are right in a lot of ways. For emissions laden 80s junk, it isn't bad at all, and does last well the B280+ years. I completely agree with your point about original designers, engineers and builders. It isn't like you have toyota's (or many others I'm sure) capitol/revenue/size to spend 1 million dollars a day on research and testing. Or a team of designers, engineers, testers, and a factory to re-create a whole car back to new...that isn't practical. You also don't have a lot of bean counter business fellows or overhead, either.

I can think of an example of DOHC being easy for t-belts/chains...one cam gear drives the other internal to the cylinder head. Then you have a single chain drive for both well oiled or direct gear drive for both. Lasts forever, and if done well, easily serviced when needed every ~200K miles.

Thanks for documenting it all so well. It's your project and your thread. I did kind of want to jack it and think out loud and just see what you would say. If you want it deleted or edited, I will, its no big deal. The project and engine is very interesting. I am working so much right now that I haven't touched a car to keep as a personal/project in a long time now.

No problem, James. Your input is always welcome, so never hesitate to jack one of my threads. Once I get something meaningful done on this car I will create a sanitary "project" thread, and will rename and keep this thread as a record, 'cause there's been some interesting discussions.