Some ideas and rationale for (re)building a B3

[Safety Guy]

Purpose:

-Getting about 10 percent more power from a stock engine for a little extra power, but not at the expense of fuel economy. (Mods to increase fuel economy, if possible.)

-B3 will be used for a max mpg Festiva build. I don't "need" more than 70hp, if that.

-My B3 "build" is actually a rebuild. This is just as much of a learning experience as anything else, and will precede my performance rebuild of a B6 or B8.

-I have two B3s: one from my '91 with about 123K miles that seemed quite peppy, and one from my '92 (@95K miles) which seemed to lack about 10hp, but ran well enough. (I think something is wrong with cylinder #2.)

Since I have two B3s and need the practice, I just want about 5 to 7 more hp for my rebuilt engine. My ideas are to do a basic Stage One mod of improving air flow through the engine. Consider the following:

-I'll read up on port and polish and do a very light job on my B3 head. I can practice on my old '89 head from Muttstiva, which I kept. If I goof that up, I have one of the other two B3 FI heads to mess up before I have to get it right.

-I'll probably have a valve job done. Aren't there specific valve jobs to increase performance, or would they be too costly? (This is mostly a DIY project.)

-I'm wondering since '88 and '89 B6 (older models) intake and exhaust manifolds are supposed to be compatable with B3s, that I could use an older B6 exhaust mani to flow more exhaust. Wouldn't it be a little larger, and thus serve as a "cheap header?" After the downpipe, I'd probably go with my usual 2" Magnaflow low restriction cat, but put in a 1 7/8" pipe and muffler to cut cost and weight.

-Would there be any advantage to using an early B6 intake as well? Or would that just waste fuel from the larger B6 TB? I'd still be running the B3 injectors, which would be sent to a competent vendor for cleaning and metering. (I'd have eight of them from which to choose the four most "balanced.")

-I'm thinking of using a lightened flywheel, perhaps around three pounds lighter. Nothing drastic. My ideal mpg car would run 165/65s on Honda VX 13" wheels, which are pretty light, too. I'd run manual Aspire front brakes.

-I think there are rods from other B series engines that are lighter than the stock Festiva B3 rods. I would use them if I could find a set that was cheap enough. This would be more reduction in rotating engine part weight.

That's about it, aside from my aero mods to the car body. I just want a bit more power without sacrificing (or even improving) my mpgs. While some will say it's a waste of time to rebuild a B3, I want to do it for the practice and I have two whole engines to use for parts. In other words, if I mess up, I got more. (I even have the three heads.)

Thoughts or advice? I hope to begin this summer.

After a B3 rebuild, I will probably do a similar mild build on a B6 before I tackle a more serious performance rebuild on a B6 or B8 for my "performance Festiva." That build will involve around a 15 to 25 percent increase in power.

Thanks,

Karl

[wybnrml]

Mattdickmeyer did that. And I really liked his builds. But he was able to get 71 HP to the wheels with some easy mods. This should help you out. http://www.fordfestiva.com/forums/sh...ad.php?t=27805

[villageidiot]

i would send the crank and rods and pistons and flywheel and clutch and have it all balanced. that alone makes things real sweet

[Kraig]

Roller rockers from an Aspire?

[bhazard]

Karl your mods involve boosting high rpm power, which doesn't help MPG. Low end torque is the key to MPG. It also helps get your car moving.

Have you thought about compression ratio? Have the head shaved to the max. Maybe deck the block too. 10:1 and run premium. Maybe even higher.

[htchbck]

Roller rockers from an Aspire?

I second that, I did that to a '92 for a lady I used to work with, she brought it to me for a HG and I had a spare Aspire head in the garage so I slapped that on. She claimed about 3-5MPG increase after that, depending on how she was driving. I can't verfiy it because its not my car, but she came to me telling me that without even knowing I had swapped the head, so I doubt it was the placebo effect. I know when we put a carb (solid lifters, no rollers) head on my roommates aspire just to keep it on the road while I rebuilt his head he lost about 3mpg on average over the course of about 5 tanks till we finally got his roller head back on it. Maybe difference in valve lift, or the cams may have a different duration, I don't know. Keep us posted on your project though, I'll be watching this thread as I too have two B3s at the house which together might make me a decent runner, might try some of the same stuff you are thinking of... or I might go B6/B8 lol, too early to tell. At any rate this summer I'm planning a mild rebuild on the wife's '88LX.

[FestYboy]

Karl, you're mods should be in the direction of port velocity and cyl compression (both static and dynamic). when Matt Dickmyer was building his B3 the most impressive par was the torque curve of that engine (FLAT). other than the tune, the way he was able to do that was with the long intake runners he built. i've been debating on building a spacer for between the upper and lower intake manifolds to increase the runner length and thus port velocity at lower RPMs. th next thing you can do is port match. then there's re-profiling your valves and a 5 angle valve job. shave the head, fill the combustion chamber to incite a "faster" burn and that would also increase the quench area. ceramic coat the pistons. pre-heat the fuel via the coolent. i would try running the longer early B6 exhaus mani for more torque production as well. you can also go the route of moding your water pump to run electricaly via a thermostatic switch (2 speed).

and then there's the Aero mods you can do as well.

[Safety Guy]

Thanks for the feedback!

VI wrote:

"i would send the crank and rods and pistons and flywheel and clutch and have it all balanced. that alone makes things real sweet."

The reason I didn't mention this was I've heard that Mazda B series engines are already well balanced and well built. I could send my crank away to get checked I suppose. As for my pistons, I could weigh all eight and choose the closest four. Would that work? Same with rods, although I'd like to use any lighter rods if available.

Kraig and htchbck, I like the idea of the Aspire head and roller rockers. That would be an easy, relatively cheap mod.

Bhazard, I don't want to run premium, so if I increased the CR, I would only do a little bit, but not to the point of having to use a higher grade of gas. Are there any guidelines to raising CR "a little bit?"

Okay, based upon what everyone wrote, I think I'm seeing things better now. However, this is supposed to be an inexpensive build, though I wouldn't mind putting $200 to $300 into custom work. I have the two B3s and I'm not counting $$ to spend on an Aspire head and other used parts (which I may be able to score cheeeeeep!). So total engine cost should be under five or six hundred at most, including HG and seals, etc. (With two good engines I don't think I need a whole rebuild kit.)

If I could get 2 to 3 better mpg and only 2 to 3 more hp, that would work really great! Lower end torque is great, too. I don't need high rpm screaming, especially since I want to save gas.

Now let me cover Arty's stuff:

"Port velocity": I'll need to look this up and read on it more.

"CR": not enough increase to require more than regular gas.

"Long intake runners": This sounds right. Does anyone know if the older B6 intake could be used or modded easily to accomplish this? Or just add a spacer to the upper and lower B3 intake? Are Festiva and Aspire intakes about the same, or does one have an advantage? I'm familiar with Mattdickmeyer's B3 thread, and I thought it was wonderful. However, I only want a 10% or less increase in hp at the crank, not the wheels. Realistically, about 4 to 7 hp is my goal. An increase in torque is better, IMO.

"Port matching": I can probably do this myself, very carefully.

"Reprofiling valves and five angle valve job": I've read about this before and will consider having it done. It will probably cost, but may be worth it.

"Fill combustion chamber": If this is to increase CR, I don't think I need more than some head shaving to accomplish that.

"Ceramic coat pistons": To keep them cooler? Hotter? Cleaner? What does this do for fuel economy and how much would it cost?

"Preheating fuel": If this is as simple as wrapping some fuel line around a heater hose, maybe. Otherwise, it is probably more work than I want to do.

"Early B6 exhaust manifold": Aha. I was right! This is part of my plan if it will increase lower end torque.

"Electric WP": Probably not. Too much work and I need to conserve my $$.


To sum up, with two decent, fairly low miles B3s, a selection of used parts from Aspires and older B6 engines, the usual new gaskets and seals, plus maybe up to $400 tops for custom work, I will be trying for a few more mpgs with a few more hp, but mainly wanting more low end torque.

Two more focused questions:

What custom work would be most cost effective here and work best with an older B6 exhaust manifold and Aspire head with roller rockers?

-Custom intake manifold or spacer
-Five angle valve job
-Ceramic coat pistons
-Balancing parts (crank?)

Which of the above gives "more bang for the buck?"

As far as testing is concerned, I hope to get my wrecked Twinstiva ('92L) fixed and running and put the rebuilt engine in her to compare with the bunch of gas station mileage receipts I have collected for the few months I ran the new 165/70-12s on the front. That should be a good baseline to compare with the new engine during the same time of the year (late summer through fall).

Thanks,

Karl

[ToSloTrk]

I've had good results with these mods:

ported head (ported myself, didn't make ports any larger just smoothed them ond took the shelf off the exhaust port) also smoothed & polished comb. chamber
Valve job
milled head .030 (I still run 87oct)
FMS cam.
homemade ram-air

I made a noticeable jump in power.nothing crazy but a nice boost.
Gained 4.7 mpg 8 tank avg.(4 before & 4 after)

[villageidiot]

When you balance an engine, balance the entire rotating assembly. While balancing can scrub a little weight off the pistons. Grind a little off the rods. You mentioned lightened flywheel. That will help the motor spin up faster, but will take away inertia and possibly reduce mpg.

[getnpsi]

I think a well thought out first gen b6 build can have power and still be right there with b3 mpg numbers, especially around town if you baby it. More tq will get the car moving so lighter flywheel wont hurt. The b3 I agree it could.

[FestYboy]

Now let me cover Arty's stuff:

"Port velocity": I'll need to look this up and read on it more.

"CR": not enough increase to require more than regular gas.

"Long intake runners": This sounds right. Does anyone know if the older B6 intake could be used or modded easily to accomplish this? Or just add a spacer to the upper and lower B3 intake? Are Festiva and Aspire intakes about the same, or does one have an advantage? I'm familiar with Mattdickmeyer's B3 thread, and I thought it was wonderful. However, I only want a 10% or less increase in hp at the crank, not the wheels. Realistically, about 4 to 7 hp is my goal. An increase in torque is better, IMO.

"Port matching": I can probably do this myself, very carefully.

"Reprofiling valves and five angle valve job": I've read about this before and will consider having it done. It will probably cost, but may be worth it.

"Fill combustion chamber": If this is to increase CR, I don't think I need more than some head shaving to accomplish that.

"Ceramic coat pistons": To keep them cooler? Hotter? Cleaner? What does this do for fuel economy and how much would it cost?

"Preheating fuel": If this is as simple as wrapping some fuel line around a heater hose, maybe. Otherwise, it is probably more work than I want to do.

"Early B6 exhaust manifold": Aha. I was right! This is part of my plan if it will increase lower end torque.

"Electric WP": Probably not. Too much work and I need to conserve my $$.

Two more focused questions:

What custom work would be most cost effective here and work best with an older B6 exhaust manifold and Aspire head with roller rockers?

you can run 87 oct in an engine with 11:1 CR with a proper tune so that's a non-issue.

the longer runners are a way to increase port velocity at lower RPMs, thereby increasing torque. you'll want an adjustable cam gear to help with tuning this aspect.

filling the combution chamber is not to increase the CR as much as it's to increase "quench" which helps in a more complete burn (higher efficiency).

piston coating is to keep heat in the chamber (increase efficiency) i have it done in Scrappy and it wasn't that expensive at all (Swain Tech)

pre-heating the fuel by wraping copper line around a coolent hose and insulating the area. i'm thinking using the heater core lines.

the electric water pump could be made for under $50.

as for ballancing, its there for durability and drivability, adn if you want lighter rods than the B3, you'll have to go with Honda rods and custom pistons...

and as you know, the aspire rockers need to go along with the aspire cam...

[econoaddict]

I have thought about going through a B3 as I use my festy as my DD and would love to have a nice new engine.
Not sure if you have looked into this yet or not but to do a PROPER rebuild you are way shy on your $$ figures.
Just the machine work and a master rebuild kit is more than double what you have listed to spend. + any custom stuff and other parts needed.
Master rebuild kits run $300ish-$450ish pending which brand you like.

[getnpsi]

I'd like info on the electric water pumps, if anyone has used them on non-drag race only v8 engines, you know on stuff that's used everyday.

[villageidiot]

I'd like info on the electric water pumps, if anyone has used them on non-drag race only v8 engines, you know on stuff that's used everyday.

vw's and jaguars, use a bosch electric w/p as an auxiliary pump. i dont think its enough to flow a whole motor alone.