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Howdy, folks!
I'm just getting started on a complete engine build project, and I wanted to pick everyone's brain for the best way forward here.
Let's have some fun, shall we? We're working on the next powerplant for my 1970 145s. I'll blow the money, I'll do the work, you get to play with engine config ideas at someone else's expense.
In my garage, you will find:
I have an 8-bolt B20F block (498049) with worn bores but otherwise in good shape.
I have an extra 6-bolt crank lying around, plus a spare set of 6-bolt style rods.
I also have the 8-bolt crank and rods that came with this block.
Oh, and I've got a line on some 93mm pistons with 22mm wrist pins, allegedly compatible with the 6-bolt Volvo B20. They're from a Holden inline 6 and they've been slightly modified as to wrist pin setup. So, going overbore does not mean going 8-bolt. Allegedly.
I have both B20B and B20F heads lying around.
I have steel cam gears lying around.
I've got an ipd Street Torque cam, but it's still being used.
The 8-bolt motor came with what looks like an ipd cam of some kind, well-used but not obviously defective in any way. It is prob. a Street Performance.
Oh, and I've got a blower sitting in a box in my attic. Really. Used, presumed good.
What do I want? Well, we're building a station wagon. It has a tow hitch. I want Torque. Power, meh, gimme Torque.
Budget? Whatever. I'm not married, so I can spend twenty grand if I want to, but then I'd have to go out and earn all that money back. Plus, I'm a cheapskate. So, let's just say, spend away but make it really really worth the money.
So, my questions:
1. Do the 6-bolt benefits outweigh the seat-of-the-pants engineering required? I'm under the impression that the 6-bolt crank is the way to go, because the rods are so much better. Less reciprocating mass, by a lot. Plus, I've already got pistons. No problems using this in an 8-bolt block?
2. Which cam would be best on a 2.2l overbore that's never likely to see anything over 5000 rpm?
3. How much fun am I gonna have with compression ratios?
4. Anyone know anything about doing a stroked motor?
5. Who's the machinist of choice in the pacific northwest (Seattle/Portland)?
That ought to be plenty to chew on for now. What's your dream motor for this job? Thanks in advance for your experience and wisdom.
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I've used the Holden pistons since the late '80's, they are too short & they are not full floating, but they were the cheap way to go at the time. Are your pistons Duralite? Anything less is weak.
Stroking gets you to 2.3-2.4 litres, but if you don't have a serious head, it won't go any better than a 2.0-2.1 litre once you get to 3000 rpm, so it basically becomes a wank.
What have you got for a gearbox, intake & exhaust?
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Three 164's, Two 144's, One 142 & a partridge in a pear tree.
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Cool, you've got experience with this. Let's see what we've got.
Yes, the pistons are indeed Duralite. And, er, they're full floating. May have had some machine work done to make that happen. I don't think there would have been anything wrong with using interference pins but here these are in all their full floating glory. Held 'em up against my old ipd 2200cc pistons and they're very nearly the same size.
As for the "too short" part: you mean the distance from the pin to the top of the piston is too small, right? Gotta watch for that. It is nice that it's too short rather than too tall, though, as normally you worry about CR being too high when boring it out... anyway, thanks for the warning, I'll pay attention to this and deck and/or choose head gasket to get the CR I want. Which is currently, um, undecided, because I might or might not want to try using a blower... yiminy, this is getting complicated.
I guess choosing a CR is the next thing to do, isn't it. Blower, or no. Gotta choose. Or I could just build it at 8.7:1 and it would run okay whether lightly boosted or not.
The big problem with using a blower is, well, then I've got to upgrade everything else.
The B20F head is nicely ported and polished with big valves and double springs... it was more than sufficient for the 2.2. Don't know how much more I can expect to get out of it, but remember, I WANT a low-revving motor. Performance increases above 5000 rpm will never matter. Wanks are hot.
Exhaust? It's a decent 2.5" exhaust, with a Clifford header that I've always regretted buying.
M41 from 123gt, has D-type overdrive. Not exactly the beefiest OD unit, but it survived my last 2.2!
Stock driveline. Yes, it's the smallest one.
Naturally, I'm thinking that a forced-induction 2.2 would annihilate my overdrive and my driveshaft. Which would be the first to go? Is it time to do a Mythbusters special on this?
As for fuel, I've got no problem building a new system to match whatever engine gets built.
I have do two things lying around: a DGV (which can be set up well for a NA 2.2, but is probably a bad idea to use with a blower) and a k-jet system (likewise.)
Anyway, there it is. Thanks for your input. Get back to me if you can remember just how "too short" these pistons are!
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You would not put boost on a cast piston. The Duralites are shorter than stock, so you have to mow the top of the block to get the quench height & compression you want, but that should be fine with an F head.
Loose the Clifford header. 4-1 does not work without a big cam & some DCOE's.
Blower: You want 3.56" bore maximum, I don't even like going over 3.625"/92mm for an NA motor
I'm thinking that a forced-induction 2.2 would annihilate my overdrive and my driveshaft. Which would be the first to go?
The shaft would be OK & the U-Joints aren't that small. I like to use a small shaft that has the big flange & U-J at the diff, that's the weak U-J. The big E shaft doesn't actually fit the car properly.
If you have the manifold for a DGV, I would adapt a 500 2bbl Holley to it.(minor mods needed) Ultimately, DCOE's or DHLA's are the only way to go.
The B20F head is nicely ported and polished with big valves and double springs.
What size valves? What does it flow?
I WANT a low-revving motor. Performance increases above 5000 rpm will never matter.
Mitsubishi rod stroker. 4G63 rods ride on a 45mm crankpin, which is 9mm smaller than the stock B20 pin, so that gives you 89mm stroke. 4G54 pistons coupled to those rods give the right height. 4G54 pistons start at 91.1mm, so that gives you 2320. They go +0.5, +1.0 & +1.5, so 92.1x89 = 2371cc
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Three 164's, Two 144's, One 142 & a partridge in a pear tree.
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You need to get in touch with Phil Singher, on Whidbey Island.
He has done all the things you mention. You'll find his writeup on the MPPE very interesting.
His website is www.vclassics.com
You can e-mail him at [username follows] editor [at] vclassics [dot] com [nothing follows]
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George Downs Bartlesville, Oklahoma
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