higher compression ratio and head swap

[syed3000]

My car has B1 engine, the 1139cc variant, I wish to increase the compression ratio of it, So I want to shave the head, so can anyone advice me, how much mm can I get my head shaved and how much the stock block can handle the compression ratio??? and will High compression only affect the acceleration or the top end too?
also plz tell me is it possible to bolt on a b6 head on a b1 block jst like b6 head on b3 block which many guys have done here ????
thanx in advance guys for ur reply

[syed3000]

hello? somebody reply me please

[ShadyRacing]

i don't think that many here got the 1,1 engine. its a bit rare i am afraid. most of the cars got the 1,3 engine stock.

instead of using a b6 head only. i would put in the complete b6 engine.

[syed3000]

well ok forget abt b1, just tell me abt b3 to b6 head conversion? Getting the whole unit wud be quite expensive for me, so I was thinking to get b6 head only and getting it shaved around 2 mm for high compression
do u guys think it will give better response???

[funky technician]

ya, it will make a difference, get the exhaust manifold too, and if ya can , the intake manifold, and if you want to up the compression, get a welder to fill in some of the extra head cc volume the b6 head has.

[syed3000]

well as far as I remember in some other thread u had written that to regain the original compression we have to get the head shaved by 1 mm, so I was thinking for going for extra high compression, so how about getting it shaved by 2 mm??? how much maximum compression can the festiva support and how much mm can I get the head shaved? can I even go for 3 mm???

[syed3000]

stock festiva comes with 9.7 : 1 Compression Ratio, so If i can get the Compression to be around 12.5 : 1 CR, in the b6's head, so then due to super high compression plus bigger valves of b6 and better porting in it rather than restrictive port of b3, so won't it increase the top speed of my car?

[mooseheadc]

stock festiva comes with 9.7 : 1 Compression Ratio, so If i can get the Compression to be around 12.5 : 1 CR, in the b6's head, so then due to super high compression plus bigger valves of b6 and better porting in it rather than restrictive port of b3, so won't it increase the top speed of my car?

It would, but having to run Race Gas or straight Alcohol
so it won't sound like somebody dropped a handful of marbles
down the intake manifold everytime you tap the gas pedal, sucks.

I've run a '70 Mercury with a 429 and 11+ point compression.

It doesn't like 93 pump gas. Or pump gas with octane boost
and the timing retarded to keep the SOB from pinging. :pukeleft:
It liked 105 octane leaded race gas.

http://www.geocities.com/vpracegasatlanta/vpfuelprices.htm

Now do you want to pay per gallon prices like that just to say
you're running the highest compression Festiva in the land? :scratch:

Leave the compression alone, except if you need to take a little off
for a good head gasket fit.
If you want power, the Mazda B series is best served with a turbo. :thumbleft:

[funky technician]

ya, i wouldn't go too crazy with the compression, just try to regain the lost compression from the extra head volume, which isn't really that much

[syed3000]

what can happen with too much high compression?
If I get 98 octane fuel plus change the radiator if the car overheats, then wont it be better?

[mooseheadc]

what can happen with too much high compression?
If I get 98 octane fuel plus change the radiator if the car overheats, then wont it be better?

without a knock sensor, you have to listen for predetonation,
-ping- or your motor wont last long. Adjust the base timing
to where in hard driving, you don't hear ping. Retarding the timing
reduces performance. One step forward, two steps back.

You wouldn't make enough power from high compression
to worry about overheating, unless your radiators old and clogged
with scale.

The easiest way to more power is more displacement. Best
fix for a Festy is to yank the B3 (esp any B1 motors!)and
drop in a B6. All bolts right in, for pre-1990 SOHC models.
Easy HP, and you won't notice a drop in MPG, but will notice
extra HP, esp if you put in the DOHC version, but that means
a bit of work on the intakes and other areas.

For more metalwork, the 1.8L BP from a Protege, 115HP.
More than twice what you are running now, and these motors
are plentiful in junkyards--cheap-- compared with having a shop
work on your heads. Depending on the shoprates, you might
be able to get two junkyard motors for the price of headwork.

Then if you need more power, go Turbo for either BP or B6

This gets you in the 130+HP range, and its almost a bolt in with
enough junkyard hunting and a little more fabrication. Then you
need to worry on tranny life. :twisted:

[syed3000]

thanx for your reply moosehead, can you give me an idea how much the whole b6 block costs from junkyard?

[Guest]

BP EGT info..

1990-1994 Protege (not sure of the specific model as some had the 1.6/1.8L SOHC variant of the BPD8)
~1991-1996 Escort GT/Escort LX-E
~1991-1995 Tracer LTS
~Later model Miata 1.8s
~Later model Kia Spectras

Specs on the BPD8 and the Transmission that came with it.

Engine Built by: Mazda
Engine Code: BPD8
Engine Size: 1.8L (1838 cc or 112 cu in.)
Type: Inline
Base Cylinders: Four
Engine Management System: VICS
OBD: 1 (OBDII came on 95.6-96 models)
Valvetrain: DOHC, 16V
Redline: 7000 RPM
Compression Ratio: 9.0:1
Bore x Stroke: 3.27 x 3.35
Internals: Forged steel
Drivetrain: Front wheel drive (FWD)
Chassis Code: CT-20
Transmission Type: 5 Speed Manual
Transmission Model: G5M-R (used in 1991-1992 Models, 1993-97 5 speeds were called G25M-R)
Gear Ratios:
1st: 3.30
2nd: 1.83
3rd: 1.31
4th: 1.03
5th: 0.79
Peak Horsepower: 127 hp @ 6500
Peak Torque: 114 lb ft @ 4500

[mooseheadc]

thanx for your reply moosehead, can you give me an idea how much the whole b6 block costs from junkyard?

Here in the Midwest, Normally a couple hundred bucks for a good runner
with 70-120k miles. You can spend more or less, depending. Above
price is pulling it yourself, so you can normally get the harness and
other goodies at the same time. They pull it, you'll get the long block,
but may not get the other bits like the Alt, PS pump, etc.
Sometimes you can get the whole wreck for not more more,
take it home and strip it, sell the extra bits on Ebay, then take the carcass
back to a metal salvage yard and still get something back, and
make money on the deal-- even pay for itself, and you keep the Motor

B6 is getting rare, but many more Mazdas (and Escorts) with
the BP, similar price.

[syed3000]

well I searched in my local junk yards and there is no B6 available there
yes you are right, they are really extint
so I was thinking, will it be possible for you guys to get a B6 from your local junkyard and then ship to me?
and please quote me the exact prices, so dat if it works out, I can send you guys the money
Thanx in advance