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MrSpArkle
07-07-2002, 09:21 AM
My father insisted that we re-use the headbolts.  This is going to be the 3rd time we use the same set.  The compression is at 180... What should I do? Just leave them in there?

1989 240sx stock
uiuc240
07-07-2002, 12:32 PM
Don't do it.  Get some ARP ones or OEM Nissan and do it right...or you might be doing it again.  The bolts are designed to stretch as you torque them.  Single use only.

http://members.aol.com/carleyware/library/ic697.htm

Eric
MrSpArkle
07-07-2002, 01:03 PM
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiuc240 @ July 07 2002,1:32)</td></tr><tr><td id="QUOTE">Don't do it. Get some ARP ones or OEM Nissan and do it right...or you might be doing it again. The bolts are designed to stretch as you torque them. Single use only.

http://members.aol.com/carleyware/library/ic697.htm

Eric</td></tr></table><span id='postcolor'>
The head has already been installed. &nbsp;What do I do?
uiuc240
07-08-2002, 09:23 AM
Well, just drive it. &nbsp;No point in going back in there now. &nbsp;If something really bad happens, then something really bad happens. &nbsp;Don't worry about it. &nbsp;Just keep an eye on your coolant and your oil to make sure the head it sealing well. &nbsp;That should be the only problem. &nbsp;I'd say unless you're running boost or high compression, you'll probably be fine. &nbsp;Now go drift!

Eric
MrSpArkle
07-08-2002, 05:52 PM
Is it safe to replace the bolts without replacing the gasket?
Maybe do them 1 by 1?
uiuc240
07-09-2002, 08:24 AM
hold on a minute. &nbsp;are we talking about the same thing? &nbsp;i'm talking about the HEAD bolts/studs, but it sounds like you're talking about VALVE COVER bolts. &nbsp;if this is true, you can do whatever you want with those. &nbsp;they are low torque, and only there to keep oil from seeping out around the valve cover seal. &nbsp;that's not a high pressure area. &nbsp;please clarify what you're referring to.

Eric
MrSpArkle
07-09-2002, 05:17 PM
I'm talking about the head bolts.
Would it be safe to replace the headbolts one by one without replacing the head gasket.
uiuc240
07-09-2002, 05:27 PM
hmm...i have no idea about that. &nbsp;sorry, man. &nbsp;check on some old-skool hot-rodding web pages.

Eric
Jammon
07-11-2002, 09:08 AM
No you would need a new gasket .. the head gasket is a crush type gasket that seals when u torque the head down.
same as exhaust gaskets. i just replaced my warped head and made the same mistake of useing the same head bolts .. but as long as it was torqued properly it should be just fine unless it gets really hot

hope this helps l8r
flipboi13
07-15-2002, 02:49 PM
This is my suggestion, but if I were in your shoes, I would take the bolts as carefully as possible and as soon as possible. &nbsp;ALL head bolts are meant to be ONE use only and are then thrown away because sometimes even if you see no wear in them, the metal is stretching bit by bit and will eventually twist right off on you, leaving nothing but a headless bolt stuck in your engine body. &nbsp;Its well worth the money to get new head bolts everytime you pull the head and like uiuc said, get ARP bolts which are the best in the business or OEM will do fine since you're going to throw them away anyways.

BTW: I'm not saying your dads wrong... no wait, i AM saying he's wrong, but in the old days, before I was born, people used to reuse the head bolts a few times for some reason I don't care about, i was sleeping in class.... &nbsp;

NOTE: UIUC?? Who cares what some dude in boofoo Illinois says?? &nbsp;LOL!! &nbsp;

j/p uiuc240 (i'm from uic)
phase2
07-15-2002, 02:55 PM
We have re-used SR20DET head bolts up to 3 times w/o any problems. &nbsp;The key is check signs of stretch, and make sure you clean the surface of the head and block carefully. &nbsp;If the motor has been through overheating, send it to head shop to re-deck if needed.

Certainly we don't recommend people to re-use so many times, so just do it at your own risk.

Wayne
mrdirty
07-15-2002, 04:28 PM
U don't generally re-use any highly torqued bolt because in the process of torqueing you actually bring the bolt to just under yield, and stretch the bolt slightly... Then the next time it will not hold the same pre-tentsion (torque) as before

However: If you get a bolt to specified torque, this is just as strong a connection as a new bolt provided you don't put more load on the connection than the connection should take before seperation (of the two surfaces).

So what that means is that if you've got the bolt to full torque, it's fine; walk away...
MrSpArkle
07-16-2002, 08:53 PM
Thanks for the help guys, the car has been holding up fairly well for the last 400 miles, and the compression has gone from 180 to 185....

The motor has been running a little hot though. So I ordered a flex-fan to allievate some of the heat. &nbsp;Thing is I can't seem to find a spacer that fits on the water pump. &nbsp;The spacer that came with the fan had a 5/8" hole to accomodate the center of the water pump, but the water pump seems to need at lease a 1 1/4" hole. &nbsp;I guess this is what I get for going on the cheap and not going electric...

Any suggestions? How much would a machine shop charge me to make that hole on the spacer bigger?