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Sentra Specialist
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Discussion Starter #1
Does anyone know of a comprehensive list of cyl. head casting #'s for the GA16DE engine. I am aware of two different heads, but there may be more. My '93 has a 57Y casting #, which can be seen easily, on the pass side front of the head, by the side engine mount. As far as I know, there is a later head ['95 and up?] that is reputed to be worth an additional 5-hp. Has anyone got the low down on this? If I'm going to port my head, I might as well start with the best one.
 

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freakish poster
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1,236 Posts
Are you looking for those 5 HP from the '95 up (110 vs. 115)? I do believe that was achieved through "micro polishing" of bearing surfaces and cylinder walls. Basically, what they did was to put on a more perfect and fine polish on the surfaces to reduce frictional loses.
Somebody correct me if this isn't entirely true.
 

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Sentra Specialist
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Discussion Starter #3
Thanks Centurian, You are right about the micro-polishing. Additionally, few people realize that in the interest of lower friction, Nissan also went to a single compression ring, on '95 and up GA16DE's. But there still is a difference in the cyl. heads, and I went to Kojima's garage, [http://www.sentra.net/tech/garage/engine.php?] and found these quotes: "Of the years of GA16, the better head to use for performance work is from the 95-99 GA16DE. This head has larger ports than the older 91-94 variant. The late head also has intake ports that are a straighter shot into the cylinder. The older head directs the port flow to the side which was probably done for more intake swirl. The later ports shoot straight in and flow better. The easy way to spot an older head is the manifold which kinks to the side on the older heads. The new style head is good for about 5 more hp over the old style head." What I'd like to know, is what the casting # is for the '95 and up heads?
 

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Sentra Specialist
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Discussion Starter #5
Thank you Mike! I will continue to see if I can find any other casting #'s for the newer models. I am very keen on technical info. for cylinder heads. It's my beleif, that on a normally aspirated engine, all of the bolt-ons in the world are compromised, without a properly ported cyl. head.
 

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Registered
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I,ve been building motors for along time. The secret to making big power is mostly the camshaft and cylinder head! Anyone can rebuild your motor. Anyone can put headers, CAI, ported throttle body etc. but, the difference will be the cylinder head and its porting and the design of the camshaft.
 

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Flux Capacitor is the key
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573 Posts
Doesn't the casting of the block also make a difference in the total power your engine can handle? Also, do you know here it is possible to get good casted cylinder heads from? I'm talking about high power performance heads for the GA6DE I'll do a search as well..
 

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3 bar MAP
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thats good info about the differences in between b13 and b14 heads.

anyone ever take a GA head to a flow bench?
the only info ive ever seen about GA flow #'s is from the mather motorsports webpage http://www.mathermotorsports.com/html/timmotor.html

"With the shortblock done, work was concentrated on the cylinder head. I flow-tested the standard cylinder head to establish a baseline. The intake port of the standard head flows 102 cfm and the exhaust port flows 67 cfm. (measured @ 10" of water and .350" valve lift). This displays a typical Nissan shortcoming in the exhaust flow, as the exhaust-to-intake proportion is only 66 percent, while I like to see somewhere in the region of 75 to 80 percent for optimal power. Since oversized valves were not in the budget, and maintaining proper airflow velocity is crucial to street use, the cylinder head could not be radically ported. Instead of just enlarging the ports, they were only mildly enlarged and reshaped, with emphasis on the exhaust port. The end result was 115.5 cfm on the intake port and 83.5 cfm on the exhaust port. The proportion was better, at 72 percent, but not as good as hoped for."

i wonder if anyone will ever get the head to flow as much a honda head.
p&p b18 head vs stock b16 head
 

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Wise Cracker
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5,730 Posts
More info.

There are at least 2 different heads for the B14's. ON the B14's they are interchangable though. Putting a B14 head on your B13 is rather hard to do as there are a ton of little parts needed to make it work including the intake manifold and TB. The B14 head design is different than the B13. Kojimka pointed out in the sentra.net tech. section that the ports on the B14 head are straighter then the B13 and appear to flow into the combustion chamber a bit better.
 

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Flux Capacitor is the key
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573 Posts
Hmmm...the only thing preventing our sentras from high gain is the stupid cylinder heads like Kojima states. If only there was a company out there that made a good cylinder head for our cars. That would be the very first mod I would buy.!
 

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Sentra Specialist
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1,902 Posts
Discussion Starter #11
javierb14 said:
I wonder if anyone will ever get the head to flow as much a Honda head.
p&p b18 head vs stock b16 head
***** Well, I took the flow numbers that Bob LeGere tested from Tim Mather's GA16DE engine, and converted the figures to 28" of water. This was done by using this conversion factor: 10" X 1.673 = 28"
This conversion method is not dead accurate, but it will give you an idea. I came up with these results:
INTAKE
Honda: 230 cfm, Stock GA16DE: 170 cfm, Bob's ported GA16DE: 192 cfm.

EXHAUST
Honda 155 cfm, Stock GA16DE: 112 cfm, Bob's ported GA16DE: 139 cfm
Note: the Honda figures I used were based on .350" of valve lift, as that was the max lift for which the GA head was flowed.
 

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Flux Capacitor is the key
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573 Posts
What does cfm stand for? I never studied my fluid dynamics in engineering schooll...LOL

Also I did a search on this...and I was wondering. How can we make our own cylinder heads? I mean where can we get one custom built for our own specifications? Would I have to get one from a machine shop??
 

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Bob also notes that he didn't do an extreme port for budgetary reasons, suggesting that there's some room to grow in the 1.6 head. Don't know if there'd be enough there to catch up with the B16, though.
 
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