1957 evinrude lightwin 3hp (3024)

[loupis]

Re: 1957 evinrude lightwin 3hp (3024)

good beta there. I'll give it a try. It could be backwords or warped. Any hints on cleaning up the block as well.<br /><br />When i retapped the bolts (all 6), I changed the thread size to 5/16, but I still have torque problems with 2 of the bolts - i'm thinkin of tryin a helicoil. The aluminum is really soft and I had to shorten the bolts due to losing the bottom 3/16 of each hole.<br /><br />does the tab go up or down on the head gasket?<br /><br />loupis

 

[Paul Moir]

Re: 1957 evinrude lightwin 3hp (3024)

Ok, it looks like the engineers were going for a 1400 lb clamp load per bolt with the 1/4-20tpi head bolts. To get the same clamp load, you'll have to tighten those 5/16-18tpi bolts to 88 inch/lbs (73-103 inch/lbs). If you're stripping out these bolts, I strongly suggest you have your torque wrench calibrated - which must be an inch/lb reading one, not ft/lbs as they are inaccurate at lower ranges - or borrow one that you know to be good. As for fixing the bolt holes, if you can still heli-coil them then that would be a good idea. A bottoming tap might save you too.<br /><br />I belive the tab goes up on the headgasket, but the problem is you can flip it to either side. Though it looks symmetrical it isn't quite.