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<table border="0" cellpadding="1" cellspacing="1" width="99%" align="center"> <tr bgcolor="#000000"><td> <table border="0" width="100%" cellpadding="3" cellspacing="0"> <tr bgcolor="#000099"> <td colspan="2" align="left"> <font size="2" color="#ffffff" face="Verdana, Arial"> <b>T O P I C R E V I E W</b> </font></td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,11,38,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Just wondering if you guys thought this was ok or weird or anything.<br />Mainly, I'm wondering if 'possibly' I'm hanging a valve open ever so slightly, or if the reduced compression #'s would be attributed to<br />1) cam bleeding a little compression +<br />2) increased combustion chamber of TFS TW heads (61cc + mild smoothing porting that probably added 1cc to each combustion chamber) vs. the iron GT-40 heads on factory 93-95 cobras which are supposedly milled ever so slightly for 58-59cc sized combustion chambers.<br /><br />well, the #'s<br />#5 150<br />#6 150<br />#7 158<br />#8 152<br />#1 165<br />#2 152<br />#3 165<br />#4 152<br /><br />These are all 'cold' readings. <br />IIRC , cold readings previous to swap where 160+ on all 8 with former GT-40 iron + stock cobra cam.<br /><br />Previous 'hot' readings were all over 170.<br /><br />Just curious/paranoid. <br /><br />(cam stats, Anderson N-41 222/230 @0.05, 110 LSA installed 105.5 ICL, .512/.512 lift)<br /><br />I also wedged a big screwdriver in backwards in the throttle body to improve air intake during compression testing. Spun it over 4-8 times until maximum reading was obtained. <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,0,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> triple post <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>st5150</b> <br /><small>Member # 51</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,13,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> For what its worth... here are the numbers I got from my car 3 weeks ago:<br /><br />#5- 150 psi<br />#6 149 psi<br />#3- 143 psi<br />#1- 145 psi<br />#4- 145 psi<br />#2 144 psi<br />#8- 145 psi<br />#7- 149 psi<br /><br />(listed in the order tested)<br /><br />Your numbers look okay to me... but I'd test # 1&3 again. <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,15,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> yeah but I was 160+ cold on all 8 like 2 months ago, I was just wondering if I can attribute the drop to the cam + the drop in compression from the bigger combustion chamber... (which I don't have exact measurements for :/ )<br /><br />also #1 and #3 are repeatable! <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>st5150</b> <br /><small>Member # 51</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,19,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Do all cylinders "keep" their pressure?<br /><br />What I mean is.... 5-15 seconds after you stop cranking, does the compression guage needle start to drop quickly or does it stay put at 160? <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,21,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> The gauge I use stores maximum value :/<br /><br />'course harbor freight (or is it summit?) has like a $30 leak-down tester. That would settle the 'hanging' exhaust valve question... <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>Yellow94GT</b> <br /><small>Member # 431</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,13,33,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> I'm not even going to share the numbers fomr my last compression test, (yes, they are that bad <img border="0" title="" alt="[Eek!]" src="eek.gif" /> )<br /><br />Lets just say, be happy with what you have <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>90LX</b> <br /><small>Member # 1487</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,14,32,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> This is off the topic but shadetree do you still have those GT-40's. If you do, do you want to sell them <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,14,36,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> ok this is the third or fourth time I've been asked that question in 2 days.<br /><br />*attention*<br />The GT-40 irons on my former combo are going to be stage 0.5 ported (by me) and dropped off for a 3-angle valve job and then they're going to be dropped in a junkyard 302 and dropped in my brother's former 6 banger '65 coupe (aka rustbucket)<br />*attention*<br /><br />thanks <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /><br />(I think that 2700# car will see 12.1s @ 111 w/4.10s and ET Streets, said GT-40 irons,junkyard 302, 650 carb, edelbrock perfomer rpm carb intake, and a gearbanger riding a fox T5)<br /> <br /> <small>[ January 29, 2003, 02:39 PM: Message edited by: shade-tree ]</small> <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>90LX</b> <br /><small>Member # 1487</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,14,39,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Sorry for asking! <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,14,41,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> no need to be sorry <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> just trying to clear things up! <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>93PONY</b> <br /><small>Member # 60</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,16,0,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Hey Joe, GT40 irons come stock with 65.5cc chambers. <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,16,5,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> searched the corral archives, that's the size from the motorsport offerings, OEM 93-95 GT-40 irons were in fact milled... <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>93PONY</b> <br /><small>Member # 60</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,16,10,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Are you telling me I have a 9.6-9.7 to 1 compression motor!?!<br />I shoulda' cc'd the things while they were off... <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>TheBrain</b> <br /><small>Member # 35</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,17,33,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Joe, <br />D.F.W.A.I !!!!<br /><br />Cold compression readings mean absolutely DICK and are unreliable<br /><br />For what it's worth, the above initials stand for Don't Fucking Worry About It<br /><br />Later<br />Brian <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>jmcclesk</b> <br /><small>Member # 1355</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,17,50,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> what the brain said <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>CobraSVT2001</b> <br /><small>Member # 2309</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,29,17,53,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Do you still have those GT-40 headds and if so do you want to sell them.. <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> j/k<br /><br /> If the #'s are all close together.. don't worry about it.. Unless they are really low.. They look about right. <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>st5150</b> <br /><small>Member # 51</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,30,1,40,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> For what its worth... I've done before and after tests with a warm and cold motor. Almost a 10 psi difference across the board. <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>street_illegal_stang</b> <br /><small>Member # 1554</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,30,11,43,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> if it makes you feel any better i got 60 psi with the number 8# cylinder on my stang <img border="0" title="" alt="[Roll Eyes]" src="rolleyes.gif" /> <br />try checking it when its warm.. <img border="0" title="" alt="[Wink]" src="wink.gif" /> <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>93PONY</b> <br /><small>Member # 60</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,30,21,0,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> IMO compression tests are not worth the effort. A leak down test is MUCH more informative.<br /><br />The heads/cam profile play a big factor in your readings. Basically, your heads/cam combo don't flow shit at such a low rpm. (starter cranking speed) Low air velocity through the motor. <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>Blown Mystic</b> <br /><small>Member # 476</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,30,21,9,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> </font><blockquote><font size="1" face="Verdana, Arial">quote:</font><hr /><font size="2" face="Verdana, Arial">Originally posted by 93PONY:<br /><strong>IMO compression tests are not worth the effort. A leak down test is MUCH more informative.<br /><br />The heads/cam profile play a big factor in your readings. Basically, your heads/cam combo don't flow shit at such a low rpm. (starter cranking speed) Low air velocity through the motor.</strong></font><hr /></blockquote><font size="2" face="Verdana, Arial">Yeah, that and they are usually depressing <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,31,9,22,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> I appreciate all the replies.<br /><br />However, I stand by a quick compression test to verify a proper valvetrain rocker adjustment relatively quickly. I mean either your valves are hanging open or they're not.<br /><br />I just fixed my vacuum leak (solid 13" at idle now) and of course it runs beatifully. With a vacuum leak and 5" of idle I needed to do a sanity check on the rocker adjustment stuff. <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>93PONY</b> <br /><small>Member # 60</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,31,11,45,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> You have more trouble in the garage then anybody I know.<br /><br />I've never had problems with vacuum leaks. Well, not big ones like that! Sure, I work slower then some, but I check/double check everything. The worst I had on my car was a hole in the oil pan & a leaky valvecover seal which were vacuum leaks.....Yes, vacuum leaks on my car! Don't ask, it's an original setup. <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,31,11,49,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> well, nothing in my car is original except for parts of the wiring harness and the alternator so I'm probably not doing too badly.<br /><br />(I did the rear, suspension, control arms, tranny, clutch, motor swap, multiple head/cam/intake packages, etc.)<br /><br />anyways, I suck. oh well. Just a hobby... <img border="0" alt="[Whoo Whooooo!]" title="" src="graemlins/woowoo.gif" /> <br /> </font> </td></tr> <tr bgcolor="#dedfdf"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>93PONY</b> <br /><small>Member # 60</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,31,12,16,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> Hehehe, I remember meeting you at the track. <br /><br />Me: "Hey bro, your smog pump is about to fall off. It's hanging the timing pointer."<br />You: "Huh? (checks) I hope it falls off."<br /><br />Hahahahah! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> <br /> </font> </td></tr> <tr bgcolor="#f7f7f7"> <td valign="top" width="18%"> <font size="2" face="Verdana, Arial"> <b>shade-tree</b> <br /><small>Member # 298</small> </font></td> <td width="82%"> <font size="1" face="Verdana, Arial"> <img src="https://californiafords.com/ubb/posticon.gif" border="0" alt=" - " /> posted <script language="JavaScript1.3" type="text/javascript"> document.writeln(timestamp(new Date(2003,0,31,12,47,0), dfrm, tfrm, 0, 0, 0, 0)); </script><hr /> </font> <font size="2" face="Verdana, Arial"> thanks for pointing out the smog pump, seriously. I had forgot about that obviously.<br /><br />anyways, I'm spinning crank+alt+H20 only right now with the smog bits put in the shed till '04 <img border="0" title="" alt="[Wink]" src="wink.gif" /> <br /> </font> </td></tr> </table></td></tr></table> <br /> <br />
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