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reversion question help!!!!!!!

Old 06-08-2009, 06:35 PM
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Has the intake manifold been checked to make sure it mates perfectly to the head, especially near the water jackets? I agree with Raylar that it wouldn't seem that the exhaust on only one side would leak and not the other, but I also see Getrdone's point about there being small cracks and when heated they seep more. Just to rule it out, I would check the intake mating surface and then try a different exhaust.

Last edited by niceguy; 06-08-2009 at 06:40 PM.
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Old 06-08-2009, 06:35 PM
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Reversion gets worse when the idle is lowered. Loosen the tailpipe at the header joint and see if water drips at idle. I ran the same cam and water poured out when I tried that. Had to go to dry pipes. The fact that your tailpipes have no drop might be it.
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Old 06-08-2009, 07:55 PM
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yes the intake appears to fit the heads perfectly so I don't think that's it. the headers were my other motor 4 weeks ago and were fine with no leaks. it hasn't been cold so I think I can rule out any cracks. I do have a little bigger motor and a slightly bigger cam (little more duration)but other than that these are the same heads and intake that were in my 632. when I took the heads off to replace the head gaskets I sent them back to the machine shop and had them tested and they are fine. I am thinking it may be reversion as I can see some water puddling up in the tail pipes and since they are dry to the tip they shouldn't be wet there?
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Old 06-08-2009, 09:59 PM
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Originally Posted by lake speed
yes the intake appears to fit the heads perfectly so I don't think that's it. the headers were my other motor 4 weeks ago and were fine with no leaks. it hasn't been cold so I think I can rule out any cracks. I do have a little bigger motor and a slightly bigger cam (little more duration)but other than that these are the same heads and intake that were in my 632. when I took the heads off to replace the head gaskets I sent them back to the machine shop and had them tested and they are fine. I am thinking it may be reversion as I can see some water puddling up in the tail pipes and since they are dry to the tip they shouldn't be wet there?
Try and run it at between 2000 and 2500 for 15 minutes or so, then check. I can't imagine that reversion would be an issue at this RPM however not certain. If there is no indication of water I would say it's reversion.
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Old 06-10-2009, 11:45 AM
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Just a thought here, couple of questions again, how is your exhaust system configured from the risers back and what headers do you have? what type of vertical fall between the riser and the tips?
also, do you know the LSA on your camshaft grind in the engine?

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Old 06-10-2009, 12:44 PM
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Originally Posted by Raylar
Just a thought here, couple of questions again, how is your exhaust system configured from the risers back and what headers do you have? what type of vertical fall between the riser and the tips?
also, do you know the LSA on your camshaft grind in the engine?

Best Regards,
Ray @ Raylar
my headers are cmi split tops. they bolt together with a 4 bolt flange at the riser. then they go back to a v band clamp for the tail pipes which are dry to the tips. these headers were on my other motor 4 weeks ago with no issues. the cam has a 114 lobe seperation. the headers do not have any fall. the tail pipe is basically parallel to the motor. in other words the tail pipes exit over the transom and through the hatch like a jet boat. the cam isnt really what most would consider "big" at .647 lift intake and exhaust. the duration @.050 is 258 intake and 266 exhaust and again its on a 114 lsa. I have a pretty extensive drag racing background so I am not a complete idiot but this thing is whipping me lol. can timing contribute to reversion? such as having too much initial timing? in other words if the initial timing was set at 36 degrees I am not sure what my msd distributor advances at degree wise but I am sure the shop that put the motor back in had the base timing at 38 degrees and thats waaaaaay too much as my 632 only liked about 36 total. I just found that out this morning and also that the cam wasn't degreed in and I now think thats the problem. thats why the engine needed 38 degrees of timing to idle any lower than 1100 rpm.

Last edited by lake speed; 06-10-2009 at 02:03 PM.
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Old 06-10-2009, 02:17 PM
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What type of distribution pump/thermostat system are you running? The water in one side could be caused by a cold water bypass, possibly favoring one side and condensing in the exhaust. I have had engines that would cause a milkshake look inside the valve cover before the oil got up to temp.
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Old 06-10-2009, 06:09 PM
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I find it hard to believe that one CMI would be bad, considering the money for those. But getrdunn might be on to something. After they heat up they might open a crack or leak.
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Old 06-10-2009, 06:19 PM
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Belay my last. sorry I missed some post's.


My engine builder took the springs out of the MSD and locked it @ 29 degrees advance. I think? And considered a retard box to try to prevent reversion. ( I can't remember for sure what it was locked in at.)

comp cams lobe sep. 114.0 230 236exh @ .050duration
lift @ .613 .608exh Stock exhaust manifold. Still reversion I'm looking @ EMI or the sort.
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Old 06-10-2009, 07:10 PM
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the motor is going to stotler race engines in the morning. I am tired of screwing around with the current situation. the cam was not degreed in and I believe that is is actually installed 4 degrees retarded and thats why the motor will only idle with 38 degrees of initial timing. I believe cam timing is my problem now. the cam is a teague spec comp cam and the fellow at teague said the cam needs to be installed 4 degrees advanced and it was not installed that way. I will update as I know and I really appreciate all the advice guys.
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