team Tickfaw

Can anyone tell me the torque for the bolts on Gill headers? Do I need to put lock tite on them? After running my engines for approx. 10 hrs had to remove exhaust ( long story ), and found that all the bolts on the exhaust were lose. Proably 15 lbs torque. I tightened all these myself with a torque wrench but only had mercruiser specs to go by. Also the bolts use washers but not lock washers. Merc says to put 35 lbs on the stock ehaust.

mats

I dont remember the torque but I think it was in the order of 35 as for the stock manifolds. However, I do remember that you should re-torque the bolts after running the engine for a while.

stevesxm

funny thing about exhaust... mine came w/ stainless bolts and washers which loosened up all the time...i replaced them with gr 5 and lockwashers and essentially fixed the problem... much better clamp load... still had one or two that would slacken up....
replaced w/ gr 8 w gr 8 lock washers and that ended the problem once and for all. also noticed that my gills had witness marks where the manifold would interere slightly w/ the head casting before it pulled up tight... ground THOSE away and made a huge dif in keeping things tight.

jmherbert

Stainless are a no-no for exhaust. they expand a lot when heated, which is why they loosen up over time. I've seen hot-rod guys use them, and keep tightening them up until they are so streched they break, and out comes the motor.

With that said, there may be 'special' grades of stainless bolts for exhaust that I don't know about.

team Tickfaw

Thanks, mine does not have stainless bolts. I will try the higher grade bolts and use lockwashers with the flat washers. I will also check for any clearance problems. Don't think I have any cause they all loosened up on both engines.

stevesxm

make sure lock washers are gr 8 ... as in heat treated... makes a big dif.

and of course you are correct about the stainless... i KNEW that ... but because was new to this boat thing thought they might have been some mystical MARINE stainless... annggggggg.... wrong ans.

jmherbert

The mystical part is that they charge you 3 times what they are normally worth, because it says MARINE

Strip Poker 388

iTrader: (6)

The Merc 500efi's and other models that have CMI's have ARP Stainless header bolts. You could get the lengths of yours and order some stainless ones direct from ARPYou wouldn't have to worry about rust and lock washers.But there$$$

On mine ,After putting on new gasket the gasket compresses and needs to be retouqed once or twice after that no retourqeing.

Killer_TA

I run the ARP stainless on my TA and they never loosen up. So does any one have the torque specs for the gill exhaust. I just took them off my self and could use the specs too.

team Tickfaw

Got all new grade 8 bolts and lock washers today. Found all that I needed at lowes building supply. Been getting all my stainless bolts, screws etc there also. Alot cheaper than anywhere so far.
I guess I will retorque at 35 lbs unless someone comes up with something else.