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Main : Misc A14 990 casting MPG combustion chamber

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A14 990 casting  MPG combustion chamber
A14 990 casting MPG combustion chamberPopular
SubmitterfemtnmaxMore Photos from femtnmax   Last Update2008/12/15 2:32    Tell a friendTell a friend
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Shown with Felpro A12 head gasket

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The comments are owned by the poster. We aren't responsible for their content.

Poster Thread
D
Posted: 2019/12/5 10:48  Updated: 2019/12/5 10:48
No life (a.k.a. DattoMaster)
Joined: 2002/10/28
From: under the Firmament LOL no twiglight effect BS
Posts: 10924
 Re: A14 990 casting MPG combustion chamber
The photos don't exist here anymore but I recall
the valves also sitting deeper in the head and
the valves are shorter length due to this.

Poster Thread
TexasMidget
Posted: 2019/12/5 18:55  Updated: 2019/12/5 18:55
Home away from home
Joined: 2015/11/10
From: Fort Worth, Texas
Posts: 213
 Re: A14 990 casting MPG combustion chamber
Did you have a 990 head before? Curious if this would bolt down to early A12 motor and how it would perform with stock pistons. Closed chamber will bump compression.

Poster Thread
ddgonzal
Posted: 2019/12/9 10:25  Updated: 2019/12/9 10:28
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Joined: 2001/5/3
From: 48 North
Posts: 31575
 Re: A14 990 casting MPG combustion chamber
Yes, it works with A12 engines

The closed chamber was deep vs the shallower but wider open chamber. So not much difference if any in the CCs. As usual the various piston dishes were used to fine tune the compression ratio. For 1980 various A14s had -- if I recall correctly -- four different dished pistons

this diagram shows the 990 head (dashed lines) vs the H95 head (solid lines)

H95 has the raised valves (1981 head for USA)

Poster Thread
D
Posted: 2020/3/9 4:53  Updated: 2020/3/9 4:53
No life (a.k.a. DattoMaster)
Joined: 2002/10/28
From: under the Firmament LOL no twiglight effect BS
Posts: 10924
 Re: A14 990 casting MPG combustion chamber
H95 head seems to be the one to spruce up for a good street engine.
Suitable for long duration cams as the valve is much deeper in the head
suiting a very efficient combustion just needs short turn radius opened.
Might be very suitable for boost due to compact inlet charge dynamics.

Poster Thread
D
Posted: 2019/12/1 11:34  Updated: 2019/12/1 11:34
No life (a.k.a. DattoMaster)
Joined: 2002/10/28
From: under the Firmament LOL no twiglight effect BS
Posts: 10924
 Re: A14 990 casting MPG combustion chamber
That doesnt look like an MPG style combustion chamber
on the H99 we saw in the past pics, maybe thats a worked one?

Poster Thread
ddgonzal
Posted: 2019/12/4 10:31  Updated: 2019/12/4 10:32
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Joined: 2001/5/3
From: 48 North
Posts: 31575
 Re: A14 990 casting MPG combustion chamber
MPG engines came in different types
* 1979-1980 H99 (closed chamber)
* 1981-1982 H95 (oval port)

H99 was also used in FU engine. Before that FU used an open chamber round port A14. MPG was just the new marketing name for the FU package

Poster Thread
ddgonzal
Posted: 2019/10/28 9:43  Updated: 2019/10/28 9:43
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Joined: 2001/5/3
From: 48 North
Posts: 31575
 Re: A14 990 casting MPG combustion chamber
This is the MPG head (miles per gallon)
* Closed chamber (heart-shaped chamber) for superior power
* A14 round-port for increased mid-RPM horsepower

The MPG engine was used with 5-speed B210 for excellent fuel economy -- 50mpg in 1978

See our tech article: Quench

Poster Thread
TexasMidget
Posted: 2019/11/26 4:26  Updated: 2019/11/26 4:26
Home away from home
Joined: 2015/11/10
From: Fort Worth, Texas
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 Re: A14 990 casting MPG combustion chamber
DD,

Can you advise on the valve sizes for the 990 head? Not much information on TechWiki. Is this a desireable head? There is one not too far from me with the A14 FU engine.

Poster Thread
ddgonzal
Posted: 2019/11/29 6:25  Updated: 2019/11/29 6:27
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Joined: 2001/5/3
From: 48 North
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 Re: A14 990 casting MPG combustion chamber
Valve Sizes

A14 37mm inlet, 30mm exhaust
except A14 H95 has 35mm inlet

The H990 round-port heads came in FU and MPG cars so they have standard size A14 valves. H95 came in all 1981-1982 USA cars and they are oval port heads with the small intake valve

Yes 990 is a desirable head for mid-range RPM. Only if you like to rev the engine up to 6000 RPM would a standard oval-port head make more power

Poster Thread
TexasMidget
Posted: 2019/11/29 14:51  Updated: 2019/11/29 14:51
Home away from home
Joined: 2015/11/10
From: Fort Worth, Texas
Posts: 213
 Re: A14 990 casting MPG combustion chamber
Thanks DD. Is there a difference between the "FU" engine and the B210 engine, Teckwifi refers to the "high line" engine. Any differences in camshaft or piston dish? Would a 990 head on high line engine produce a higher HP engine? The B210 engines I have seen have the H72 open chamber head. If the FU engine is strickly for fuel economy, I would only pick up the 990 head from this vehicle.

Poster Thread
ddgonzal
Posted: 2019/11/29 19:41  Updated: 2019/11/29 19:51
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Joined: 2001/5/3
From: 48 North
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 Re: A14 990 casting MPG combustion chamber
The FU engine is a B210 engine, strictly for Fuel Economy but uses higher efficiency to get there (superior power at mid-RPMS). The FU designation was carried over to the B310
* Piston dishes always varied, up to six different dishes for A14 in the same year!
* Camshaft for A14 cam in three flavors: Mid-RPM (5600), Standard RPM (6000) and high-RPM (6400). FU engines came only with the mid-RPM camshaft
* many years the FU used the superior closed-chamber heads. H72 in USA used open chambers so not as good -- but still made more HP (due to larger oval ports) if you revved it to 6000 RPM. H72 castings were factory machined with closed chambers in some countries


High Line engine is a chassis code thing so it depends on the year. The base engine was always A12. The high line engine is...
1973 HB210 is A13
1974 HB210 is A14
HB310 is A15


990 is the casting number
H990 is the part number. H991 is a different part number (same casting, but machined in a different way)

Poster Thread
TexasMidget
Posted: 2019/11/29 22:21  Updated: 2019/11/29 22:21
Home away from home
Joined: 2015/11/10
From: Fort Worth, Texas
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 Re: A14 990 casting MPG combustion chamber
I will post on Main Forum since I cannot post pics here.

Poster Thread
A14force
Posted: 2008/12/15 6:19  Updated: 2008/12/15 6:19
No life (a.k.a. DattoMaster)
Joined: 2003/12/3
From: Christchurch NZ
Posts: 3706
 Re: A14 990 casting MPG combustion chamber
Does this head have an "H" number on it?

Poster Thread
femtnmax
Posted: 2008/12/16 23:56  Updated: 2008/12/16 23:56
Not too shy to talk
Joined: 2008/6/9
From: MT
Posts: 31
 Re: A14 990 casting MPG combustion chamber
No it does not. Has 990 near #4 cylinder and 415 at the #1 end.