engine advice when it comes to torque ratings.

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BlackStar
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engine advice when it comes to torque ratings.

Post by BlackStar »

As it says in my build thread, my engine failed on start up, it blew its head gasket. The believed cause, as of now, was me incorrectly torquing down the head. When I get back to the states, I am going to get another torque wrench(non beam style) and head gasket and get back to work.

however

I am now worried about the rods and mains. They felt damn tight, but This doesn't instill confidence. What I am thinking about doing is taking off the engine pan, and either checking or re-torquing the mains and rods. I did some research, and apparently there is no tool that magically checks the amount of torque that is on the bolt currently.

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Re: engine advice when it comes to torque ratings.

Post by dr.occa »

Can check with a good working torque wrench set at the specified torque.

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Re: engine advice when it comes to torque ratings.

Post by wizzurp »

Always follow FSM torque specs. They have a reason.

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Re: engine advice when it comes to torque ratings.

Post by BlackStar »

dr.occa wrote:Can check with a good working torque wrench set at the specified torque.

wouldn't that continue to tighten down the bolt though? That was my understanding.

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Re: engine advice when it comes to torque ratings.

Post by wizzurp »

No, if it's set to 70lb/ft it'll click at 70lb/ft so it shouldn't torque any more unless you keep turning.

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Re: engine advice when it comes to torque ratings.

Post by BlackStar »

wizzurp wrote:No, if it's set to 70lb/ft it'll click at 70lb/ft so it shouldn't torque any more unless you keep turning.

good to hear, thats the route I will take. Any suggestions on brands? I have heard that one form autozone will get the job done, but I personally have had a hit or miss with their tools actually working. Harbor Freight, Oreilly, Craftsmen? I dont have a huge budget, so a high quality snap on would be out of the question.

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Re: engine advice when it comes to torque ratings.

Post by hotdoghogie »

No TQ wrench is 100% from the factory, they all technically should be calibrated. I brought my Kobalt to work and it was dead on for calibration out of the box. Anytime a TQ gets dropped it needs recalibration, which is sketchy.

But in your case man, those Crafstmen, Oreilly's, and sadly even Harbor Freight would suffice.
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Re: engine advice when it comes to torque ratings.

Post by BlackStar »

since my engine is just going to be a commuter 4ac, I think i can get by with an ok wrench, I wont be drifting or high reving whatsoever

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Re: engine advice when it comes to torque ratings.

Post by dr.occa »

wizzurp wrote:No, if it's set to 70lb/ft it'll click at 70lb/ft so it shouldn't torque any more unless you keep turning.
^Exactly.

Craftsmen, Kobalt, and yes even harbor freight torq wrenches are pretty spot on.

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Re: engine advice when it comes to torque ratings.

Post by ga_goosh »

maybe you didnt tourqu it right. from what iv read is you tourqe it to 22 ft/lb in the proper order then change to a regular breaker bar/ratchet and turn each bolt 90 deg in the proper order then do it 90 deg again in the proper order and that is your 3 step tightening sequence.

someone on c4ag said they came out with something like 108 ft/lb after all was said and done.

iv read that the beam tourqe wrenches are supposidly more accurate then the clickers. the clickers are just more convenient. they also go bad faster especially if you dont unload the internal spring. you have to take more care of them and make sure not to drop them or it can throw off the accuracy.
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Re: engine advice when it comes to torque ratings.

Post by dr.occa »

Sean actually brings up a good point. I know I forget to because I'm lazy but you SHOULD unload the torque spring by removing any torque settings when you're done.

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Re: engine advice when it comes to torque ratings.

Post by wizzurp »

Guys above have good advice, I've personally got a craftsman one that has been good for several engines :)

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Re: engine advice when it comes to torque ratings.

Post by McKenney »

I found that 65 foot pounds is exactly what you end up with doing 22 then 90° then another 90°. I just start out at 25, then 45 then 65 using stock head bolts. If using ARP, you can go up to 75 for that extra squeeze.

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Re: engine advice when it comes to torque ratings.

Post by hotdoghogie »

McKenney wrote:I found that 65 foot pounds is exactly what you end up with doing 22 then 90° then another 90°. I just start out at 25, then 45 then 65 using stock head bolts. If using ARP, you can go up to 75 for that extra squeeze.

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Sketchy, bolts stretch and new threads will give. I'd rather trust the HF special.
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Re: engine advice when it comes to torque ratings.

Post by McKenney »

I've been building motors for 22 years pal, and btw 4age's do not have stretch head bolts. They are reusable. The whole 22 lb/ft then 90 degrees then 90 degrees came from people not properly torquing in stepped sequence. So the engineers(god I hate engineers) researched the proper sequencing and noticed that from 22 lb/ft to 44 lb/ft was an additional 90 degrees orientation. And once again, an additional 90 degrees from there would achieve the desired 65 lb/ft. Same $hit, doing it with the torque wrench is more accurate.

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