I was installing the intake manifold on the new motor today when one of the bolts snapped off. Fortunately it was the one on the corner of the head, so I'm going to drill it out and fit it with a nut and bolt for now, I really don't want to mess with the threads on a cast head. I guess the shaving of my heads only affected my intake manifold in that one spot, or perhaps it was some imperfection in the intake itself. Either way, not a fun ordeal.
Yeah, I have done that too, get your hand up by the ratchet when tightening those bolts. Once bitten twice shy. Better yet, apply the correct torque spec, if using aluminum, seek the designers torque spec. Dan
How did the bolt break? If the threads were running hard it is probably jammed in, but if it was just torqued too much or a weak bolt, it will probably come out pretty easy.
that sucks! at least you didn't brake the corner of the manifold off! my buddy did that one time! lol! i also striped the head bolt in a block on time... that wasn't fun! i used an EZ Out but the block was never cuz i could the same.
I did the same thing when I put my 5.0 together . I just used an easy out to back the bolt out and put a new one in .
This is a very common problem on 302's, especially when using aftermarket intakes. The OEM bolts are good until you remove them and then it is a good idea to replace them with new ones. New bolts should be at least a grade 5 (three lines on the head) and then use a good hardened washer on an aluminum manifold. When tightening, go from the center out, criscrossing from side to side. It may take dozens of passes to get the required torque. Then always re-torque them every once and awhile using the same method. Used bolts are stretched and after several removals, will break. Found this all out the hard way too. Also there can be a reaction between the aluminum and steel, that can damage the bolt to the point of breakage. The extra cost for the better bolts and stuff is well worth it, in the long run. JMO
These were brand new bolts from a summit bolt kit. Since it's an end bolt, I'm just going to drill through and put a nut on the outside of it. Thanks for calming the nerves guys.
Wow ... aren't they only torqued to like 20lbs or something like that? Never buy Summit bolts I guess ...
Bummer, are you still putting the engine in this weekend? I used ARP bolts and my latest engine. Very high quality stuff.
My thoughts exactly. I can't think of a bolt that would snap at 20ft/lbs. I used the ARP bolts as well. They look really nice.
