Inliners International Forums General Discussion Blown and Injected 194 vs. 250

Hey guys I have a 1964 nova with a 194 in it. I am planning on building it and adding a turbo. I have been doing lots of research and even bought Leo Stanucci's power manual book. Which btw has lots of great information.

My question is, is there a huge advantage of a 250 over building my 194 other than displacement. I have quite a bit of experience with turbocharged engines. So displacement is not really relevant other than low end no boost torque. Is the block stronger or cylinder walls thicker on the 250? I plan on building it with forged pistons and rods shooting for atleast 450whp. I don't see many people building 194's. Even swapping to a 250 just to build it. So I was curious why no love for the 194. I don't see the point in playing roulette buying a used engine that may have a bad block when I have a great running engine now to start from.

Any help I get during planning is greatly appreciated.

Thanks

The cylinder walls on the 230/250 and even 292's aren't known to be considered what you would think are thick. Unless you get a Mexican block to begin with, and i've seen more of them also be as thin as a regular block than I have one's that are actually thicker by sonic checking many, many of them. Not sure how the 194 blocks compare in thickness to the others.

You will be hard pressed to get that kind of power out of a 194.

There is a better starting point to make that kind of power (256 ci GM inline 6) than the 194/292 series engines and they start out at 275/290 HP bone stock - at 10PSI they are a 450HP engine all day long with a good tune - no internal engine mechanical mod's needed.

by 256, you are referring to the atlas 4.2 correct?

I have thought of this and need to do more research but i am deadset on a manual transmission so i need to see what options are available for this engine.

Do you have any videos of youe ride, love to hear how that thing sounds.

What is the limiting factor would you guess for the 194? The head? I mean between bmw and toyota there are plenty of 3.2 straight sixes making huge power.

Yes, the siamese port design is the limiting factor and the fuel robbing characteristics betwern shared cylinders become even greater when forced induction is introduced into the equation.

4200 forum

We are actively working on a solution to the manual transmission flywheel supply issue. I would say before the end of the summer they should be available. We are waiting on sample ring gears to arrive.

As far as what transmissions you can use:

- some guys are using the supra trans and a 2.9 bell - talk to limeswap on 4200.
- with an bellhousing adapter plate you can bolt up any transmission that came behind a SBC/BBC/LS. Check the parts link on 4200.

so what would you say are the horsepower limits of a stock 194? And limits with forged internals? Obviously tune needs to be spot on and I have 93 octane in Maryland. Is 350 possible out of stock engine?

Well, there really isn't a magic number that is the limitation with a siamese port design. Forced induction actually makes this worse because as the velocity increases thru the ports, the harder it is for the air to change direction and go to the appropriate cylinder and the fuel sharing/starving issues between common cylinders worsens as well. A better option would be to divide the ports into 2 separate ones with a simple divider plate to help eliminate the problem. This has been done for many years and most recently an article in our club magazine featured a blown 292 engine in a drag car that had done this with great results. So that may be an option.

ok thanks, i'll try and do some research on it. I know my goal may be alittle aggressive but i can only do what the engine allows. I know its hard to say a specific number. I just want to plan accordingly, i dont want to build a turbo system(including fuel) that can say handle 500hp and the engine blow up at 350 or vice versa. I am still aways away from getting started on the turbo aspect of my build but any and all info i can gather will help.

I looked into the atlas 4.2 and am not ready to move onto an engine swap right now. I wanna play with this 194 and see what i get out of her.

Yes, your goal is very aggressive for one of these engines for sure. And while the 194 engine hasn't really been a choice of many to persue, i'm sure you'll be able to reach 300 flywheel HP with a moderate amount of head work and other mods. Even in N/A trim, the siamese head has its limits, and some reach it sooner than others based on the extreme they go to when building the engine.

With divided intake runners and port EFI - with the dividers extending into the intake manifold upstream of the injectors by say 1" you will be well ahead of the a/f distribution issue.

An alternative is to get an integrated head and mill the intake off of it ( of course this will need a custom intake) as it has a 12 port intake.

If you go EFI, I would suggest going big enough on the fuel supply system to handle any future upgrades. The delta cost between a 300hp and 500HP pump is minimal. For 300HP the injectors are J/Y items these days. <<< 28#/hr injectors.

The integral Cyl heads are thin and like to crack a lot. Not a good choice IMO.
Also the Brazillian 12 port head is thin also and like to crack as well.
Deviding just the intake manifold is not the main problem with air/ fuel distribution, the main focus should be in the Cyl head itself by Deviding the port, but by doing this it severely cuts down intake flow.
IIRC, Turbo6 AKA Harry had to increase boost pressure of 10 psi just to make the same HP as it made when the Cyl head was not devided.

so what about lump port kit then? should i just leave it as is or does it make it worse when adding boost?

As I understand it, the intake side is not where the flaw is... It is the exhaust. You can always force the air in... But getting it out is not as easy.
I wouldn't mind taking another look at the hybrid head. Though a royal P.I.T.A, it does look like a very valid route.

The exhaust does not flow that bad, but there is room for improvement.

If you are not looking to make crazy HP, you can devide the intake port still and it will improve A/F distribution problems that the stock head has. Better drive ability etc.
Don't let having a divider make you think it won't make good power, it is going to make power still with a turbo and you should be happy with the power output.

Maybe I missed it... Is there a tech article or similar anywhere that I can read about dividing the intake ports?

What I have seen on the forum here I would not try and copy it. You would probably better off designing your own.
I have thought about having lumps made with a partial divided intake port . Or make it a two piece deal.

The divided port would start just behind the head bolt hole. Just me thinking out loud. Having it partially divided should not kill the intake flow as it does when you completely separate the intake port.