Blown head gasket
#15
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Joined: Aug 2012
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From: Chesapeake City, Md
Its a 850 done up to a 920. Nickerson did it. Still have pv's. I have a theory on the boost. I was thinking back when I changed the pulley and I kind of remember it being about 7 to 7.5 lbs. We have had some cooler temps with low humidly. I attributed that towards the boost being up a bit towards 9lbs. Found out today that the intake valves were heading south in the bad cylinders that were beat up from heat. Because of the blower being constant positive pressure, I would never hear the tell tale sound of popping out of the carb from a bad intake valve. Lesson I learned, If the boost increases on it's own by any amount, start looking for a reason.
Ah the joys of a blower motor, having fun and still learning.
Ah the joys of a blower motor, having fun and still learning.
#16
#17
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Joined: Mar 2011
Posts: 167
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From: Beaumont TX
I'm doing a 177 on a very mild 502 right now with a 1050 dominator at 98 squared. We shall see come next week when I fire it up. Only looking to make 4.5-5.5psi. Hopefully things workout. It's a brand new build at 8.75/1 compression
#18
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Joined: Feb 2012
Posts: 101
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From: Delray Beach, Florida
Got everything back together and fired her up. Second lesson learned. Should have had the head checked. Low compression on 1 ,5 and 7. 1 and 5 being the worst. Did a leak down test and looks like the intake valve's got beat up a bit. Did a quick tear down and off to the machine shop with the head this morning.
#19
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From: Chesapeake City, Md
Hey X1, Not sure on the charge is yet as the shop/friend hasn't put the bill together yet. Why are you asking? Are you in the middle of something similar. I also had him drill out an old head so I could use it as a guide to drill out one of the head bolt threads in the block that was sloppy and install a timesert. (cool product). I'll let you know when I get the bill. He took 4000 off the head, touched the seats up and installed 4 new intake valves. Had it running today and sounds good. 150ish on the compression test cold.
#20
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Joined: Jul 2004
Posts: 11,332
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From: chicago
Hey X1, Not sure on the charge is yet as the shop/friend hasn't put the bill together yet. Why are you asking? Are you in the middle of something similar. I also had him drill out an old head so I could use it as a guide to drill out one of the head bolt threads in the block that was sloppy and install a timesert. (cool product). I'll let you know when I get the bill. He took 4000 off the head, touched the seats up and installed 4 new intake valves. Had it running today and sounds good. 150ish on the compression test cold.


