Went to the track.....now pulling motor

[nissanfanatic]

I dont think i have the power to sheer off bolts but maybe because of having ot launch so high, one may have come loose. I dont know yet but, will find out tomorrow since i got a cherry picker today but, forgot to get a chain while i was there ....

P.S.

I also found out that one of my couplers had a decent size hole in it so i might have ran faster if it wasnt for that. I will have some pics of it and the motor being pulled tomorrow night.

You don't necessarily shear off bolts from too much power. It is typically a clamping issue. Basically, bolts are supposed to operate in a single vector. All they are supposed to do is clamp two surfaces together, and the coefficient of friction, area and clamp load should dictate how much force can be applied. If the bolts back out, then you have a problem. A lot of things can come into play here. If any of the three are compromised, then you could have a failure. Three easy problems could be improperly torqued bolts (no lubricant on the threads, damaged threads), lubricant on the flywheel/crankshaft mating surface, or warped surfaces. Once one of them is compromised, it is a matter of time/frequency. The bolts could probably hold a constant 300ft/lbs of direct force. But alternating force will kill them quickly. This could be related to the theory of an impact wrench vs a breaker bar. Whether or not we feel it, our drivetrain undergoes the same stress that bolts/sockets/extensions undergo when being used with an impact gun. The engine simply exerts these forces at a much higher frequency. At 7000rpm, the entire driveline is seeing the resulting force in sine wave form at 233.3 Hz, and the amplitude can be described using cylinder pressure*area of the piston top. You could then use that force value times .1574803ft to see what torque is being made by each cylinder.

[nelson8708]

You don't necessarily shear off bolts from too much power. It is typically a clamping issue. Basically, bolts are supposed to operate in a single vector. All they are supposed to do is clamp two surfaces together, and the coefficient of friction, area and clamp load should dictate how much force can be applied. If the bolts back out, then you have a problem. A lot of things can come into play here. If any of the three are compromised, then you could have a failure. Three easy problems could be improperly torqued bolts (no lubricant on the threads, damaged threads), lubricant on the flywheel/crankshaft mating surface, or warped surfaces. Once one of them is compromised, it is a matter of time/frequency. The bolts could probably hold a constant 300ft/lbs of direct force. But alternating force will kill them quickly. This could be related to the theory of an impact wrench vs a breaker bar. Whether or not we feel it, our drivetrain undergoes the same stress that bolts/sockets/extensions undergo when being used with an impact gun. The engine simply exerts these forces at a much higher frequency. At 7000rpm, the entire driveline is seeing the resulting force in sine wave form at 233.3 Hz, and the amplitude can be described using cylinder pressure*area of the piston top. You could then use that force value times .1574803ft to see what torque is being made by each cylinder.

Most of that is way over my head but, i get the just of it and i know that clamping force is what holds it together. I got the engine out and its not the clutch or flywheel. I was susprised to see that the flywheel on has two hot spots on it. I figured that it would be a little more burnt since i had a slipping issue last year with it but, it held up great at the track.

So its defintally internal and i suspect it to be the piston / wrist pin. I have to get one of my buddies over here to take my other engine out of my stand that is in the barn so i can use it on the one in the garage. I want to start tearing it apart tonight so i can see what i need to order so i will be ready to reassemble next weekend. I will try to get a few pics up tonight.

[neverlift]

damn I had hoped it to be the clutch/flywheel for ya!

[nelson8708]

damn I had hoped it to be the clutch/flywheel for ya!

yeah me also but, atleast i pulled the motor instead of the transmission to check.

I drained the oil and the magnetic drain plug looked like it did on the first oil change when i was breaking it in. I pulled as much as i could apart to night and got it in my engine stand but, i dont have a puller so i couldn't pull the crank pulley off so i had to stop there. I screwed up the crank pulley when i tried to use a pry bar and hammer on it ...but, its no big deal. I will just get the pulley off the short block i got a couple weeks ago. Tomorrow my goal is to have the the entire engine apart so i can see what i need to order. I got my stock pistons out of my barn so they are going back in. I am going to use the rings off the pistons that are in there and give the block a light hone so they can re-seat. I believe you did that a while ago cory and didnt have any problems with blow-by because of it.

Also, do you guys think it would be ok to delete the coolant lines going to the upper part of the intake manifold? I want to delete them for a cleaner look. Do you see any problems with this? I know its common for people to cut the throttle body out of the loop but, i haven't seen it done with the intake manifold. Does the coolant heat up the intake manifold to engine temp or does it keep it cooler than if i was to not run the coolant line?

[nelson8708]

WTFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF!!!!!!!!!!!!!!!!!!!!!!

I couldn't sleep anyway so i decided to pull the rest of it apart. I dont see anything that would cause the knocking sound it made. You guys did watch the vids right? I'm not hearing $hit and I? The rod bearings look fine. Better than the main bearings do. Do the shinny spot on the main bearing mean the crank and bearing came into contact? The crank is fine. No scratches or anything on it. You can drag your finger nail across it and it is smooth. Everything was tight when i pulled it a part. The only thing i see is that the side of one of the rods looks like it came into contact with some thing. I checked the block and there is nothing else it could have touched. It might have been like that when i rebuilt it the first time.....i dont remember. At this point i dont know what to do. Do i just put new bearing in it and see what happens? The small little pieces of metal that was on the magnetic drain plug had to come from some where.

[480sx]

I wouldnt replace the bearings if they are in good shape. No reason to, and new bearings will put wear on the crank for the first few runs.

You sure that the wrist pins are O.K? Still floating in the groove?

What about your timing chain/tensioners?'

How do your cylinder walls look?

Check your rod bolts to make sure they havnt stretched.

How big were the metal shavings? Was it powdered metal or little chunks?

IDK i dont like the idea of putting it all back together without figuring out what was the cause of that noise/metal.

[nelson8708]

I wouldnt replace the bearings if they are in good shape. No reason to, and new bearings will put wear on the crank for the first few runs.

You sure that the wrist pins are O.K? Still floating in the groove?

What about your timing chain/tensioners?'

How do your cylinder walls look?

Check your rod bolts to make sure they havnt stretched.

How big were the metal shavings? Was it powdered metal or little chunks?

IDK i dont like the idea of putting it all back together without figuring out what was the cause of that noise/metal.

Yeah all the wrist pins and still floating and none have excessive play as far as i can tell but, the stock pistons are still going back in with a light hone. The timing chain and tensioners look fine. I havent got a close look at the cylinder walls yet but, i will today. If the rod bolts had stretched then that particular rod nut would be looser than the others when i pulled it apart but, i have a caliper so i can compare them real quick. The metal shavings were more powder than anything. When i wiped off the magnet is just looked like black grease. There were a few tiny slivers but, nothing bigger than the normal engine break in size.

Yeah believe me i dont want to put it back together and have the same problem agian....that would be terms to sell the car and buy another honda. ....i was actually thinking a rx7 FC since i dont think that will become a bandwagon car because people are scared of what they dont know and that is rotory power.

[nelson8708]

Here are some more pics that make it easier to see the bearings and crank. Everything looks good. The cylinder walls and i looked very closely at the pistons and there is nothing wrong with them. There is not enough play between the rod and piston to cause that noise but, i guess when it warms up the play would be increased. You can slide the rod on the wrist pin very easily but there is no actual play. I figure since it moves this easily when cold that i could make the noise when its at running temp. It sucks that i pulled his apart and found nothing wrong.....yet. Like i said the material on the magnet had to come from some where. It wasn't and whole lot of material....just more than usual. I am going to dissasmble the rod and piston and see if i can find anything wrong.

[480sx]

Dont replace the bearings, and i wouldnt hone it unless the walls are glazed, and they dont really look bad to me but its hard to tell. Even if you do, do the lightest possible hone you can. Everything looks fine..

Lol RX-7! If you dont like the idea of pulling your motor once in two years, they are not for you. Man i sweated those back in the day, until i realized how much of a pain in the balls they are. Wankel engines are such a great design in THEORY. To bad Apex seals arnt capable of maintaining compression over time with boost. After 30k miles or less, you start to lose compression, and its just downhill from there. MPGs tank, power tanks, motor smokes, ect ect. They are a great tinkerers motor, if you dont mind pulling the engine every year or so.

Its like this...

Other than that, the thrid gen rx-7 is a SICK looking car, i still love the body style. If i ever had the cash i might invest in a 4 rotor setup from Peter Ferrel(sp?). Those things belt out 1000+ hp at 12000 rpms like its their job. Dudes shop is really close to me. I used to go to his shop and.. Uh.. Chill there in my car with my boys, it was in a really remote place. Occasionally they would see us and show off some sheit. We had this one dude come out in a Miata and drift around this garage we were parked under like 3-4 laps, was pretty sweet.

Hondas arnt a bad move, i just dont like understeer.. Vtec and boost are sweeetttttttt.

RWD performance for life here.

[nelson8708]

Cleaned the block and gave it a light hone. Now i am waiting on acl bearings and a gasket kit....decided to do the bearings because i would be pissed if i put it back together and it turned out to be that.

[neverlift]

she will be back on the road in no time

[nelson8708]

Well i put some time in rebuilding it this past week/weekend.

Thursday: 4hrIt went from a bare block to a short block. It takes forever when you have to pull everything apart agian to plastic gauge it.

Friday: 4hrGot the cylinder head on it after cleaning the head gasket off the head and cleaning both surfaces. I fininshed the night by installing all the timing components and turbo.

Saturday: 6hrPut the front cover on after cleaning all the little grooves were the rtv goes. Then intalled the rear main cover and seal. Followed by the oil pickup and oil pan. Then i installed the oil pump, intake manifold, iac valve, alternator, ps pump and a few other odds and ends.

On a bad note a few things happend. I stripped a rear main seal bolt even though i was torque-ing it to 5lbs with a torque wrench .....then i blew a section of the block out when i was torque-ing the front cover . I was tighting it with the torque wrench and i didnt notice that the bolt was bottoming out instead of tighting on the front cover. I forgot that the alt. bracket goes under that bolt. So it blew out a section of the block. I was still able to torque it down after i got the alt. bracket on there though. It shouldn't affect anything but, when i happend i was so pissed that if it had ruined the block i was going to pick it up out of the stand and chuck that SOB into the street. ....but, everthing is ok at the end of the day.

On with the pics

Thursday

Friday

Saturday

For you sohc guys....you can clean up your intake manifold

[neverlift]

see another couple days and you bound to be back at it

lol throw it, wont matter, then you will have to go pick it up and get back to work glad its done man(well 75%)

[nelson8708]

My goal is to get it back in the car today and maybe get some of the wiring done. Looks like i will be ordering some 65lbs (681cc) injectors in the next few weeks. I also got a z32 mafs ......after break-in i am going to do the e85 and 10psi....I'm not going to pull any timing since its 105 octane. I heard some people go as high as 14psi before they pull timing with it.