B3 Cylinder Head Cross Section [Pics]

[blkfordsedan]

Very nice! How many hours in it so far? One nice thing about 4cyl motors, you only have half the work as a V8! That should be a nice motor...all you need now is a good performance valve job, cam & lightened flywheel!

[Zanzer]

I didn't keep count of the time because it was "a little here and a little there" due to other stuff I've been working on. This was just a guinea pig head since I've never done a B series one before. I could do another in a couple of days easily now that I know how. Plus it's aluminum so it works down fast. I had the same thought about how lucky I was that it's an aluminum 4 cylinder head....you don't wanna know how much time I have in my 429 heads!

Since this head is just for a daily driver I'm just going to do a standard valve job and rebuild, but it will be nice to see if any of this effects MPGs. I mainly did this one for some of my own personal R&D. After doing this one I'm now going to do a little port work to a 97 Aspire motor I'm installing in my blue 93. This is all in preparation for the B6ME that will be going into it later. It will get a full port and polish because I'll be going to a rear turbo setup on it sometime after I swap the motor. I know the heads are completely different, but at least all this keeps me in practice :mrgreen:

[blkfordsedan]

LOL, flashbacks of grinding the emission bumps out of the exhaust ports on Windsor heads.
I wonder if anyone makes performance hi-flow valves for the B6, or if there's another valve that would work, like for a Honda or Nissan or something.

[FestYboy]

funny you mention the "emission" bumps in the intake runners. if i were to remove the bumps in my fiero's 2.8, i'd loose up to 25cfm per runner.

[blkfordsedan]

That's pretty wild. You wouldn't think you'd lose (loose?) flow, but fluid dynamics is a strange thing. Wonder how many guys have ground them out not knowing any better.
The "bumps" in the SBF heads are on the exhaust port floor and pretty restrictive. I remember reading an article about 10 years ago where some Flow Bench guru reshaped the bumps into a "shark fin" to help direct the flow. Tests showed it actually increased the low lift flow without significantly hurting higher lift flow. He said he spent 100's of hours experimenting before finding just the right size & shape.

[Zanzer]

I'm sure you can probably find someone that makes those valves, but before I went to the trouble I'd just bolt on a B6ME or B6D head and get 4 valves per cylinder instead of 2 LOL.

The 429 and 460 heads have the thermactor boss too. It's on the ceiling of the exhaust side. It's big and it's not drilled on C8, C9, and D0VE heads so it was a total pain to remove. Luckily though you don't have to touch the intake side on those other than the valve seat back cuts. The ports are so huge they need the cast roughness.

That is kinda odd on the 2.8 Fiero motor. How is the runner designed? How do the bumps help? Does it have something to do with velocity? You got me all interested now

[thered56]

Man, you've got me wanting to build a B6 now, just for experience. I have wanted to for a while anyways, but I just wanna try my hand at all this stuff.

[Zanzer]

Any excuse is better than none I always say!

Sounds like a perfectly good reason for rebuilding a B6 to me :mrgreen: I'm going to try it on a B3 next. I've got an Aspire motor I'm rebuilding for my 93 and it's going to get this same treatment. It may not do much for the B3's performance, but I plan on putting a lot of miles on the car so if it helps MPG or just keeps it from getting a ton of carbon build up then I can justify the labor

[Safety Guy]

Zan, I have an '89 head, a '91 head and I bought a '97 Aspire head. I hope to use the Aspire head with roller rockers for my "MPG B3" build, while my only plan for saving my '89 head was to practice porting/polishing on.

Would practicing on the old '89 Festiva head before I do the Aspire one be a good idea, or are they likely to be too different from one another for the "practice" to be worthwhile? As a beginner, I'll be doing the minimum and not anything radical.

I'm working up to a B6 head, and maybe more (B8?) in the future.

Karl

[blkfordsedan]

I don't think there is any difference between the actual Festy or Aspire heads, other than the camshaft and valvetrain. I could be wrong, but if you port the Festy head you can just install the Aspire cam, rockers & shaft, etc..

[Safety Guy]

That would be nice! It would give me excellent practice on my old head before I took on the Aspire head, wouldn't it?

Karl

[Zanzer]

Good news Karl! The heads are the same The pic of the head that I sectioned is from an 88 carbed car and it's the same as the Aspire head other than the roller cam. So, if you happen to like the results of your first go at the head then all you have to do is swap the cam and valve train to the Festy head :thumbup:

It's a "win win" situation :mrgreen:


The only problem I can foresee would be if you plan on using the ported head with Aspire valve train in a carbed car. The Aspire cam doesn't have the eccentric cast into it that operates a mechanical fuel pump. So if you were planning to use the Aspire valve train on a carbed car you would have to install an external mount electric fuel pump and regulator (we're currently doing this on an 88LX that's getting an Aspire motor).

[Safety Guy]

Thanks! I'm currently on a "no carb" Festiva diet right now, so no problems with that.

Karl

[FestYboy]

I'm sure you can probably find someone that makes those valves, but before I went to the trouble I'd just bolt on a B6ME or B6D head and get 4 valves per cylinder instead of 2 LOL.

That is kinda odd on the 2.8 Fiero motor. How is the runner designed? How do the bumps help? Does it have something to do with velocity? You got me all interested now

the valves you can get from one of the members here (larger stainless flat-faced units) can't remember the guys name at the moment but las i heard he was selling his 3 turbo kit.

as for the fiero, those bumps on the intake side DO increase port velocity and smooth the flow before hitting the valve back-cut, thus eleminating turbulance before the chamber. there was an issue with the casting and port angle that caused alot of port turbulance before the valve (not to mention the poor valve guide bung cast shape) and that "shark fin" was their solution. you'll only find it on the HO 2.8 cast iron heads.

[Kraig]

Nice work......