grumpyvette Posted May 30, 2004 Share Posted May 30, 2004 ok youve assembled the short block and youve got the torque wrench to measure the rotating assembly resistance to turning, what should you be looking at to see if its correctly assembled? 19 lbs-25 lbs is EXCELLENT for the total rotating assembly including rods and rings,in a short block, for a rotating assembly on a street style engine with the rings dragging the cylinder walls/all the bearings installed and torqued in place low drag rings on a race engine can drop that into the 10-15 lb range but youll seldom see that with standard ring tension,and clearances most correctly assembled engines require slightly more than that to get them started rotating,(anything under about 35 lbs is normal, exceed 40-45 lbs and you should start checking clearances like rod side clearance, thrust bearing,crank straitnes and main and rod bearing clearances and the assembly lube used also effects the result,(of course once they start moving the required torque drops to keep them moving but I think youll find many engines require about 30 -35lbs to get them started rotating before the rings and bearings lap in) Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted June 1, 2004 Share Posted June 1, 2004 GREAT INFO!!! Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 2, 2004 Share Posted June 2, 2004 hi grumpy. Your info is always informative.I have a question. How can you check your motor if it is already installed in the car? I'm having problems with my motor shutting down. I'm thinking that the bearings are too tight. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted June 2, 2004 Author Share Posted June 2, 2004 pull all the plugs and push in the clutch or put it in neutral after the accesories belts are removed,and rockers are removed, and test with a torque wrench on the front of the crank, it should start to turn over BEFORE you get to about 40 ft lbs MAX Id be realy interested to find out why, and correct the problem if it was my car and it would not turn over before I reached 40 ft lbs Quote Link to comment Share on other sites More sharing options...
Guest butlersZ Posted June 2, 2004 Share Posted June 2, 2004 how much torque does a stock SBC starter put out to turn the engine? I seen one motor that wouldn't turn over with anything below 100 ft. lbs., my friend builtit using this really thick graphite engine assembly lube that added a few thousandths to the bearing clearences. After he found that it took that much force to turn the engine over, he pulled it back out and took everything apart and assembled it with some prolong. It took 32 ft. lbs to turn it with a torque wrench. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 3, 2004 Share Posted June 3, 2004 So Grumpy, Wouldn't the trans, even in neutral, and the assembled heads w/ rocker's installed add resistance, The only reason why I ask is because on your first post you stated Can you just clearify. Thanks for your input Grumpy. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 3, 2004 Share Posted June 3, 2004 Sorry guys, I didn't get the quote in the previous post. Here goes." O.k. you've assembled the short block and you've got the torque wrench to measure" The key word is "Short block". sorry guys. Thanks again Grumpy. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 3, 2004 Share Posted June 3, 2004 Hi Grumpy.sorry I should have read your post carefully. You did write "and remove your rocker's" That makes since. Well tonight I went out and did the test I got 65 ft/lbs. I drained the oil. and found a shock. the oil looked like mother of pearl. The filter was full of fine metal gray dust in it. I changed the oil and filter. But i'm guessing the damage has been done. I now think that the bearings were too tight. causing the motor to seize. That was why the motor was shutting down. And all my diagnosis of external accessories didn't find anything wrong. Thanks for your input Grumpy. At least I think I found my problem. Now to have go pull the motor out. Quote Link to comment Share on other sites More sharing options...
Guest butlersZ Posted June 4, 2004 Share Posted June 4, 2004 So how much do you torque the rod bolts too? I've seen books that said 40 ft. lbs and others saying 50-60 ft. lbs, I'm guessing how much you torque the connecting rod bolts to would also end up effecting the "tightness" of the engine. After reading fastzcars above post, I went and tested my engine I just built which is already in the car and got 70 ft. lbs to turn it, so I guess I'm going to pull mine out too and figure something out. Quote Link to comment Share on other sites More sharing options...
Guest roberttlove Posted June 21, 2004 Share Posted June 21, 2004 > So how much do you torque the rod bolts too? Total newb here, but: Car Craft keeps saying that it's not the torque but the rod stretch. I think the recent issue's article about "first engine build" mentions the desired stretch on a sbf 302. I believe it mentions that the torque reading can vary for a particular stretch. Maybe someone else knows more? Quote Link to comment Share on other sites More sharing options...
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