• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Street-able NA engine 8v vs. 16v

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

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 :nod:

We have a well warmed over NA B230 that makes 144 at the wheels. We have gone pretty well beyond what a normal Tbricker would do in this effort. On carbs it would do quite a bit better, I'm sure. Maybe 15-20hp. MAYBE.

I stand by my statement about the 8V head being crap. The intake ports are badly shaped and do not flow well, the exhaust ports are much too large for the application, etc. However, it is the one we're forced to use, so I deal with it. The 16V head, if I understand it, had design assistance from Porsche and flows as well as a modern cylinder head. Given that torque production, and therefore power, is nothing but processing airflow, I'd go with the 16V head. I'm not saying it would be cheaper or easier. I'm saying it would be better.
 
The forum lore stands at 230/196cfm at 11.5mm of lift, 28" for a stock 16v head. Massive gains on the intake are possible by opening and smoothing the intake ports.
 
One of the reasons I described the stuff I've experienced is because I was thinking you would want something kind of period correct to the cars age.

One of the things I think a lot of people forget is you dont' have to have some kind of magic number in mind to build a fun fast car. It's in the content of what you put together. My 240 turbo probably only makes a couple hundred hp but it's been fun and fast enough for me for many years.

The higher the rpms you go. The more you are gong to have to modify things like the water pump, and alternator, timing belt pulleys, etc. The higher the rpms the more wear on the engine. So giving up a bit of top end rpms for a bit more well rounded engine power curve will be more fun on the street and will probably last longer. But it might not make quite that magic number.
 
We have a well warmed over NA B230 that makes 144 at the wheels. We have gone pretty well beyond what a normal Tbricker would do in this effort. On carbs it would do quite a bit better, I'm sure. Maybe 15-20hp. MAYBE.

I stand by my statement about the 8V head being crap. The intake ports are badly shaped and do not flow well, the exhaust ports are much too large for the application, etc. However, it is the one we're forced to use, so I deal with it. The 16V head, if I understand it, had design assistance from Porsche and flows as well as a modern cylinder head. Given that torque production, and therefore power, is nothing but processing airflow, I'd go with the 16V head. I'm not saying it would be cheaper or easier. I'm saying it would be better.

Truthiness!

Actually.......a motor is more than this oft repeated bullsh!t its just airflow...
There's also the next step: compressing what flowed in.

And then the next step: lighting off what got compressed.
The old wive's tale suggesting thrown out sloppily "a motor is just an air pump" needs to stay in the bar and be used to impress the other chumps who are Tech Nerds and who know
_______________ from Shinola
maxresdefault.jpg


Next: 8v ports are fine size, just exhaust port is far to low and makes the short side radius --non radius.. a corner..a sharp corner.. Not nice...but because of its size, not as bad as it could be...
Both combustion chambers could be better...but they're not bad....just not cream-in-your-jeans -on -first -sight-fantastic.
But nobody here is going to do anything that either needs so that's moot.
 
I did mean to imply "...and the efficiency with which it is processed", which is why I chose that particular verb.

John's reply, however, is more correct.

Thank you.
 
I would definitely opt for a full standalone.

I am planning on full standalone (MicroSquirt or Speeduino).

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!

Those are roughly the numbers I had found regarding B230f and B234f.

The forum lore stands at 230/196cfm at 11.5mm of lift, 28" for a stock 16v head. Massive gains on the intake are possible by opening and smoothing the intake ports.

Ironically enough, today after reading this post, I finally found some OLD swede posts regarding stock flow and what can be done for mild port work.
 
B23E 140hp
B230FB 131hp
B234f 154hp

The 16v is not making all that much more power but cams are not like for like duration. What I do not like with 16v engines is the reduced engine braking but would I consider a NA 16v hell yes but I already have plenty of B20 powered cars. What is nice about a breathed on B18/20 is when someone say "gosh your car is quick what engine does it have?" you can proudly say "the original engine"
 
B23E 140hp
B230FB 131hp
B234f 154hp

The 16v is not making all that much more power but cams are not like for like duration. What I do not like with 16v engines is the reduced engine braking but would I consider a NA 16v hell yes but I already have plenty of B20 powered cars. What is nice about a breathed on B18/20 is when someone say "gosh your car is quick what engine does it have?" you can proudly say "the original engine"

even better when you pop the hood and its got a turbo stuck to it. :cool:
 
What’s there to be scared of? By the time you get it together with a new trans, clutch, ems, fuel plumbing, intercooler setup, you’re 90% done with and ohc 16v turbo swap. So if it blows its only a few things to swap in a newerer betterer engine.
 
What?s there to be scared of? By the time you get it together with a new trans, clutch, ems, fuel plumbing, intercooler setup, you?re 90% done with and ohc 16v turbo swap. So if it blows its only a few things to swap in a newerer betterer engine.

This is a good point.
 
We have a well warmed over NA B230 that makes 144 at the wheels. We have gone pretty well beyond what a normal Tbricker would do in this effort. On carbs it would do quite a bit better, I'm sure. Maybe 15-20hp. MAYBE.
Build thread or link to more info and dyno sheet? :oogle:
 
Head milled 2.5mm. Intake and exhaust port modifications. No cat. Properly sized exhaust pipe for power output. LH2.4 fuel trim tune. Ignition map modified, but not dyno tuned. The pinout grounding mod showed 0 changes to power curve in either +3 or -3 degrees so we said F it. Easiest thing to duplicate would be K cam. It's installed at -1.5 degrees because that's as close as we could get to 0 with what we had. Moving the cam timing also has little to no effect. H cam made less power. Airbox delete, cone filter.

I'll post the dyno sheet on it. 144whp @ 5744 rpm.

I can't figure out how to post .pdfs and it's pissing me off

This is the dyno run with the H cam:


thumbnail_20190422_193814.jpg
[/URL][/IMG]


And this one is with the K:

thumbnail_20190422_193954.jpg
[/URL][/IMG]

If someone can point me to somewhere where I can put up the pdfs, I'd be grateful. This looks like crap. I tried to save them as something other than pdf, no dice.
 
Last edited:
Back
Top