347 Build/Questions

First Post, I have be lurking for awhile and I have read some real good info. To start, I had a 289 in my 65 mustang and it dropped a valve and did a nice job of taking out the whole motor. I was able to save the heads and cam plus all the external accersories. (65 289 castings, 54cc 1.94 1.60 valves, ported etc, Comp XE268 cam, 0.509 0.512, 224 230. I also have a weiand stealth manifold I saved....Im thinking of stepping up to a 347 for a new motor. A few questions were however is, 1) Is a 5.4" rod pretty much the rod length everone uses for a 347? I heard some people were using a slightly shorter rod so they could run a piston with a better ring package since the pin was not so close to the top. I was looking at a company (dixie mail order) with a short block consisting of a eagle steel crank, eagle I beam rods, and some KB forged pistons. I looks like the CR would end up being around 10:1 with my 289 heads. Any input wpuld be appreciated. Thanks

I don`t think those heads would be enough for a stroker. Your compression would be pretty high with 54cc chambers.

Most people run the 5.4" rods. Newer pistons have addressed the pin in oil ring problem, if it was even a problem. 7 years ago my brother in law built a 347 and it never burned oil.
[addsig]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2006-07-10 13:47, rcm600 wrote:
I don`t think those heads would be enough for a stroker. Your compression would be pretty high with 54cc chambers.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

I know the ports have been opened up a good bit, but I have no idea what they would flow. Another company who CNC's the early 289 heads gets 215 at .500 on the intake and 173 on the exhaust. Mine were hand ported by a reputable shop, so I am guessing they would be somewhat close to those numbers I checked KB's website with their little calculator deal roughly, it ended up being 9.98. I think 10:1 would be feasible with on 93 and iron heads.

<font size=-1>[ This Message was edited by: 65fast on 7/11/06 6:24am ]</font>

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2006-07-10 15:20, 65fast wrote:
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2006-07-10 13:47, rcm600 wrote:
I don`t think those heads would be enough for a stroker. Your compression would be pretty high with 54cc chambers.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>I checked KB's website with their little calculator deal roughly, it ended up being 9.98. I think 10:1 would be feasible with on 93 and iron heads.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

Not likely if your near sea level and air is heavy...even with a big cam that's pushing it unless you have gooooood quench and set your timing curve up so max timing comes in later than normal.
Brian
[addsig]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
Not likely if your near sea level and air is heavy...even with a big cam that's pushing it unless you have gooooood quench and set your timing curve up so max timing comes in later than normal.
Brian
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

That's interesting, i've always thought it's best if max timing was in by about 3500rpm ?

Most of the performance engines we build we lock the advance out. So if you set total timing at 35 degrees, its there at idle and every where else too. 3500 rpm is really late for a performance engine. But you might need to use a curve like that to handle that compression. It would run better with a fast curve and lower compression!
Brian
[addsig]