Long story but ill make it real short im on my 3rd set or arp header bolts in past year. I will get about 2 good months out of them before i check and just like clock work theres gonna be atleast 2 bolts snapped?? All work was done by proformance shop the only reason they can think of for them breaking is that the motor is twisting very hard under WOT and putting to much pressure on the bolts and snapping them?? Im no newbie nor car mech but logic tells me if my motor is twisting that hard then i would break more then just header bolts?? I dont think the shops fing me cause all i have to do is rebuy the bolts (which arent cheap) and they replace them for free (this shop pretty much built this car) im just lost and not sure im tired of spending 100's$ a year on header bolts.Any help would be appreciated.

 

If you have stock motor mounts then upgrading to poly mounts will help keep the engine from rocking as much. Also on the "H" pipe there are hangers welded on to the factory ones and many aftermarket ones don't have them. They attach at the tranny crossmember area. Maybe welding some on if they are missing isn't a bad idea. They will help keep the exhuast from boucing and tugging on the headers.

 

not stock motor mounts. using solid currently and poly trans. Headers are hooker long tubes rubber hangers are already being used. but still the force were talking about to snap a bolt id assume id snap all kinds of things not just header bolts.

 

vibration can cause it to..since the motor mounts are solid all the engine harmonics and vibration are transmitted through the components..just an idea

 

mjr46 i do understand what your saying but wouldnt my driveline break also with the force its producing?? but see it might not be engine twist they just assume it is. as far as i can see when i romp on it(6200rpm) the motor really dosent twist it does but not like its flipping sideways and rises some but to me the old stock motor did more moving then this one i got solids to fix this problem with polys it was like an animal trying to escape so we went with solids. But bolts have broken on poly and solid motor mounts??

 

time for a motor plate system

 

The solid motor mounts are not the problem. I cant think of what could be causing your problem unless the headers themselves are in a bind because of clearance issues, have you checked to make sure your headers are true and not warped where they bolt up to heads. Are the bolt's breaking on the same side?

 

damnit now its time to google!! have no clue what a motor plate is never heard of one. but i dont listen to often

 

no ive had 3 on right side 1 on left so far. as a non mech i say i have no clearence issues shop has said nothing id assume if this was it they would fix it since im not paying for labor and labor aint free.

 

here you go