Street-able NA engine 8v vs. 16v

I'm looking for opinions/specs/dyno sheets on assembling an NA 8v or 16v engine that is putting roughly 150hp to the rear wheels. Cams/sources, CR's, head choice, etc are all appreciated.

Basically, I've decided to do an OHC swap on my 142 because I already have most of what I need, minus a physical ECU (Microsquirt or Speeduino) and some little ancillary stuff (high-pressure fuel pump, swirl tank, velocity stacks). I am planning on adapting a set of liter bike ITB's to the stock 8 or 16v manifold.

So, who's done what? I have a 16v head and associated parts, as well as a complete B230FT, so either route is doable. I'm not afraid of an aggressive cam (something that takes until, say, 3500 RPM "climb on") as bottom end torque isn't the "theme" of this build-

The B20 in the car at the least needs a cylinder head, if not a complete top end rebuild due to some poor workmanship at a local shop. I figure, if I'm replacing a head, I may as well get a somewhat warmed up unit, and that spirals into a $300 cam/gears, $1500 head, etc etc.

The 16v combustion chamber will likely have a faster/cleaner/more efficient burn because of the centrally located spark plug.
It also will not require as much spark advance so may be more fuel/tune tolerant.
With adjustable gears you can fool with the cam timing separately.
It's going to flow better too.

It's going to need double eyebrow pistons if valve clearance is needed.

Not a fan of ITB's You are not going to spin it 14k.
A long runner intake with a good plenum will help get it out of the hole, and not have the throttle shaft and butterfly in the runner to drop flow by 20%

Fairly big build.

I take it you are going to use the B230FT block, find some 16v pistons and use your 16v head. Are you going to upright the engine and use your B20 sump or planing a gearbox swap too?

I used to love big cam engine builds.
Although some good cams are available for 8v, I really like the good combustion chamber on the 16v.
Do that, don't go as big on cams (no need to, because it breathes better at top end) and get more useable midrange. Coming in hard at 2k but with ok low end is way preferable to coming in real hard at 3.5k-4k but having nothing down low.
Details. Windage tray with screen, baffles. Good induction, good tune. Good header, etc.

16V head is an EXCELLENT cylinder head, requiring little in the way of camshaft to deliver a nice torque curve over a wide rpm range.

8V head is a crap cylinder head requiring more camshaft to provide a narrower, peakier torque curve.

If the 16V is on the shelf, this isn't really a question.

Take your budget and triple it. There will definitely be more “ancillary bits” than you can even imagine with that swap. 16v is never gonna clear that brake booster which is a whole new can of worms.

Get you a b20 head with a valve job and go drive the car.

You know you can make a lot of fun n/a power with a B20 right? A B20 is like the nicer stronger version of an engine like the british engines you work on at the shop. From back in the day none of the four cylinder pushrod british engines were as good. Some came close but never as durable as the Volvo.

Funny thing was there were enough british sourced parts on a 122S that the british taxed the car less for importing. That's why the Volvo was somewhat more affordable and enjoyed by a lot of enthusiasts over in the UK.

dl242gt said:

You know you can make a lot of fun n/a power with a B20 right? A B20 is like the nicer stronger version of an engine like the british engines you work on at the shop. From back in the day none of the four cylinder pushrod british engines were as good. Some came close but never as durable as the Volvo.

Funny thing was there were enough british sourced parts on a 122S that the british taxed the car less for importing. That's why the Volvo was somewhat more affordable and enjoyed by a lot of enthusiasts over in the UK.

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Interesting. The drivertrain and suspension on the Amazons looked super English to me. Makes a lot of sense now.

AndrewNance said:

Take your budget and triple it. There will definitely be more ?ancillary bits? than you can even imagine with that swap. 16v is never gonna clear that brake booster which is a whole new can of worms.

Get you a b20 head with a valve job and go drive the car.

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This video seems to disagree with that when it's mounted at an angle. I'm planning on running a T5 with the engine tilted.

dl242gt said:

You know you can make a lot of fun n/a power with a B20 right? A B20 is like the nicer stronger version of an engine like the british engines you work on at the shop. From back in the day none of the four cylinder pushrod british engines were as good. Some came close but never as durable as the Volvo.

Funny thing was there were enough british sourced parts on a 122S that the british taxed the car less for importing. That's why the Volvo was somewhat more affordable and enjoyed by a lot of enthusiasts over in the UK.

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The durability of the B20 is a recurring theme when I really ponder this swap.
My real concern with warming up a B20 is the cost. If I'm going to rebuild/replace the head, I ought to replace it with something with some port work, and I don't know who to go to besides John Parker (big no). The HIF6's should be good for about 130hp (my boss runs his TR4 with Stromberg CD175's). I assume a D cam, steel cam gears, and some mild port work should get me to 130hp.

For flow work I use D&F performance in Berlin, NJ. They did are great job on the two heads I had done by them. Been in business since the 70s and is a family owned business.

I would suggest HS6 Su carbs. The strombergs are OK but you will deal with less problems using the HS 6 over either HIF or CD175 carbs in my experience. Strombers are also a lot more expensive for parts. Your boss shoud also change to the HS6 carbs. lol.

Now one of the old hot rod your british or swedish car things was to use one step larger SU carbs than what the car came with. For example an MGB 1800 engine used HS4 carbs stock because they had that siamesed exhaust and didn't need a bigger carb. So what the racers would do is use the flanges and carbs from a B18 which used HS6 so they get a good power upgrade to their engines. Likewise with a Volvo you would modify the manifold and use HS8 carbs like from a Jag or big Healey. then you could make quite a bit more power with your Volvo.

dl242gt said:

I would suggest HS6 Su carbs. The strombergs are OK but you will deal with less problems using the HS 6 over either HIF or CD175 carbs in my experience. Strombers are also a lot more expensive for parts. Your boss should also change to the HS6 carbs. lol.

Now one of the old hot rod your british or swedish car things was to use one step larger SU carbs than what the car came with. For example an MGB 1800 engine used HS4 carbs stock because they had that siamesed exhaust and didn't need a bigger carb. So what the racers would do is use the flanges and carbs from a B18 which used HS6 so they get a good power upgrade to their engines. Likewise with a Volvo you would modify the manifold and use HS8 carbs like from a Jag or big Healey. then you could make quite a bit more power with your Volvo.

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I've had pretty good luck with HIF6's- they are definetly more tuneable than the HS6's and a proper rebuild from Tom Bryant or Joe Curto makes for a really great unit.

The real challenge with going larger is the cost and ease of finding them. Not many cars here in the states used HS8's- most big 6 Healey's, as well as DOHC Jag's, ran HS6's and the V12's ran CD175's.

At the moment, my boss is on the fence about carbs. That engine is pretty much a fully built race engine that was running those Strombergs, though he does have a set of DCOE's that would look quite at home. My gripe with Strombergs are the rubber/viton membranes that are inside of the dashpots- one extra part to fail.

Between the cost of the membrane for the piston and the temperature compenstors. You will have spent as much or more than the rebuilt HS6 will cost you. The HS6 has even less problem parts than a HIF. Those float bowls on the bottom are prone to leaking on both strombergs and HIF. The strombergs leaking there is what killed lots of 140 and 160 volvos. At least that is what happened to one of my old 164s.

There is still lots of power and performance even with the HS6 carbs so I would just use them until you are ready for more. If you can get a chance to read up on the old Volvo performance stuff they were selling before Rsport you'll see they made a lot of streetable power. Even in the Rsport catalogs there is some good stuff to check out.

And then there are the dual side drafts which are really great when dialed in. Check out the sidedrafts in Mike jrs thread in projects on page 7. I think all this would cost you of course but speed costs either with time invested or money or both.

And then there is the guy I met a long time ago who had a 144. It had two 32/36 webers on it. He used the type of setup they use to put two of them on a TR6. That was different. I didn't get to drive in it but heard it run. He had to cut a hole in the hood to clear the air filters.

shoestring said:

8V head is a crap cylinder head requiring more camshaft to provide a narrower, peakier torque curve.

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You're advocating that he undertake a 16V build ONLY to produce 150hp at the wheels...

8V is certainly not a crap cylinder head whatsoever and for 150hp is absolutely perfect. Unless he wants to build a 300+whp car, 8V is perfect for the job

Ask dl242gt, my 8V build is awesome and produces solid power, all before I even do my bigger upgrades!

89_740Turbo said:

You're advocating that he undertake a 16V build ONLY to produce 150hp at the wheels...

8V is certainly not a crap cylinder head whatsoever and for 150hp is absolutely perfect. Unless he wants to build a 300+whp car, 8V is perfect for the job

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150whp NA out of an 8v is not easy.

Stock B234f: 154 hp @ crank
Stock B230f: 114 hp @ crank

I would think 16v would be the obvious choice, since it only needs another 25 HP (16%) to hit your goal of 150 hp at the wheels. 8v needs a 57% increase in power!

The b230 (e?) equipped with the 8V H cam was rated at 140 hp stock.

I would definitely opt for a full standalone.

There are options either way, with NA stuff, details are important. Like others have mentioned, windage, manifolds, etc... all matter.

The swedes get those numbers out of their NA motors in the controlled racing series.

8V heads are nice when packaging constraints are an issue. 16v heads are great since they are just much better designed but if you need space...

I have stock 16v and 8v intake manifolds in FXBG, VA if you need to cut flanges off or whatever for a template to work with. Also have a spare good 8v head laying around and another that has trashed cam journals if you want to practice porting.

I also have a high compression (flat-top piston) B23 bottom end, rare bird indeed in the states. Probably never gonna use it.

If you wanna talk N/A power on a B23(0), JohnV has good insight on making it. Get a case of beer and 3 packs of smokes, find a lawn chair, and give him a call.

I, too, once had aspirations of making a badass NA motor but life has tripped me up every time I get something going.

I probably have a lot more helpful bits and pieces laying around and am planning to do a big liquidation on my garage soon.

Little edit:
I'm not sure why 150whp is said to be unobtanium on an 8v without spending huge money. Open up the exhaust ports, get your squish on and find a good cam to match. A standalone with an aggressive ignition curve later you should hit that target no problem. It's gonna have to rev high but that's the price you pay with NA power. Also, I have an RSI N/A cam that I ran for a little while but I didn't have the compression and high enough rev limiter to make any real use of it. I swapped for a V cam which was a lot more streetable, especially in an automatic.

AndrewNance said:

Get you a b20 head with a valve job and go drive the car.

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DCOE's, head work (start with an injected head, work on the exhaust), cam, exhaust. It's not all that hard to get 150 - 160 hp from a B20. Of course, it takes revs, and stock pistons don't seem to be very good at doing that often.