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View Full Version : 440ex head bolt nuts coming loose


Brehmmotorsport
04-22-2007, 08:10 PM
Need some advice. My one teammate runs a 440 kit we did a year ago. It is only a 11:1 and stage two hot cam. We have even put brand new oversized headstuds in and we lock tight the nuts on top the head tight. We are on about the third head gasket now because we rebuild it torque the nuts even a little over spec and after about 15min the head gasket starts to blow out again. Just curious is it the head or is it something we are doing we are just following all the specs out of the honda manuel. The thing is the nuts are coming loose too. Any advice thanks.
zrpilot
04-22-2007, 10:00 PM
is it possible the studs are being pulled out of the cylinder? Have you tracked their length?
Brehmmotorsport
04-23-2007, 12:54 PM
I haven't measured them but they are completely tight everytime. the nuts just keep coming loose and the gasket blows out
Ruby Soho
04-23-2007, 01:39 PM
okay 2 things could be wrong.

1. You could have a warped head because the past blown gaskets.

2. Your sleeve could have sunk. just alittle bit, mine was down i think 10,000's of an inch and that was adding to my blown gaskets. What happens is the sleeve is pressed in cold and then when it gets very hot it sinks.
Ruby Soho
04-23-2007, 01:41 PM
oh ya, and just because the studs are tight doesnt mean they arent backing out. my old stock studs were all tight but some backed out alittle bit
Zemo
04-23-2007, 03:47 PM
If this was a big block Chevy (which I used to build my own race engines) I would check (a) the head and make sure it's true, (b) the top of the block for same, and (c) that the studs hadn't streched or have backed out some. I do know from reading a blurb at GT Thunder's web site that there is a known problem with studs on the 400ex http://www.gtthunder.com/TRX400EX.htm


Hope this helps some

Zemo
tippmann9898
04-23-2007, 07:33 PM
Re-surface the deck on the cylinder and head to make them true, and use a metal head gasket. My decks were warped. That's what I did to my 440 and have never had a problem with gaskets since. And I haven't even put my GT Thunder studs in yet, I'm not going to worry about it unless it blows another gasket.