Torque to turn engine

v8alex · Post by **v8alex** » Thu Nov 30, 2006 10:27 pm

I've recently rebuilt my RV8 3.5L engine. Without any spark plugs in, I can turn the engine by hand using a wrench on the crank pulley bolt.

Since then, I've added clutch & flywheel, R380 gearbox, starter motor and plonked the lot into the chassis.

Went to tighten up the crank-pulley and put 200Nm of torque on it and nothing at all moved in terms of engine rotation. The gearbox is currently in gear, but before I fitted it, it would turn over with finger strength.

Does this sound right ? The only thing I didn't check during assembly was if flywheel / clutch etc rotated before adding gearbox.

Any thoughts ?

Alex

v8alex · Post by **v8alex** » Fri Dec 01, 2006 9:43 am

Thinking more about it, it could be the crankshaft spigot bearing is too tight on the input shaft of the gearbox. When I hooked the engine and box up, I couldn't push the bellhousing flush with the engine and had to use the bolts through the bellhousing to pull it all together gradually and it took a little effort to do this.

Maybe I need to disassemble it, ream the inside of the spigot bearing and try again ??

Alex

jrv8 · Post by **jrv8** » Fri Dec 01, 2006 9:55 am

hi,
The spigot bush will have no effect on the turning over of the engine.
Sounds like something in the flywheel/pressure plate area jamming in the bellhousing. Why don't you loosen off the bellhousing bolts again and see if it turns over .

Are you sure that the gearbox input shaft was engaged in the clutch splines, before you tightened it up ?

Jim

stevieturbo · Post by **stevieturbo** » Fri Dec 01, 2006 10:15 am

clutch friction plate the worng way round ???

Little bid of advice NEVER use the bolts to pull the bellhousing up, unless you are 100% certain everything is lined up. The box should just slide in nicely, to the dowels at least.

Boosted LS1 · Post by **Boosted LS1** » Sat Dec 02, 2006 7:40 pm

Have you got a long bolt installed where it should be a short bolt? I'm wondering if a long bolt may be in contact with the back of the flywheel.

Boosted.

v8alex · Post by **v8alex** » Tue Dec 05, 2006 12:57 pm

Thanks for the thoughts. I'm going to take the whole lot out and have a look. The current position in car gives me no room to investigate properly.

My guess is that something has jammed whilst connecting the box / bellhousing to the block. I plan to assemble it again bit by bit and check each time that things turn over. I'll keep you posted

Alex

landybob_v8 · Post by **landybob_v8** » Thu Dec 14, 2006 5:12 pm

could be the flywheels round the wrong way this forces it tight onto the block and wont turn

v8alex · Post by **v8alex** » Fri Dec 15, 2006 12:58 pm

I've recently taken the whole thing apart. The flywheel and clutch are fine and engine rotates no problem on its own. Gearbox does the same.

What I noticed was the crankshaft spigot bush pressed about 1cm into the recess on the crank (it was originally flush) and spline indentation marks on the end of the crank, which were made by the input shaft. It was therefore the splines jammed into the crank that prevented the engine rotation.

This has got me thinking - it looks like everything was lined up fine, but either the input shaft is longer than expected, or the rear of the crank is too long. This may sound wierd, but it appears to be the case. One possible way forward would be to hacksaw 1cm-ish from the rear of the crank and refit the spigot bearing and then there should be enough clearence between the splines on the gearbox input shaft and the spigot bush housing on the crank.

Jim - thanks for the PM - I've called and left a message.

Thoughts / Comments ?

Alex

Post by **katanaman** » Fri Dec 15, 2006 1:30 pm

I wouldn't go hacking off the end of the crank if I were you. Something is wrong somewhere and you need to find what it is. The cranks are all the same and I cant think how it could be put together wrong for it to be in the wrong place. Just a thought but this didn't used to be an auto did it and you have left the spacer on the end of the crank that's meant to space the flex plate? If it is then take the spacer off, there should be nothing bolted onto the end of the crank where the flywheel goes. Its just you mention spigot bush housing where it should just be a hole in the end of the crank.

v8alex · Post by **v8alex** » Fri Dec 15, 2006 2:59 pm

The spigot housing is just the hole in the end of the crank.

I've spoken with Jim (jrv8) who mentions that it could be the gearbox (an R380 in my case) coming from a diesel vehicle. He has had to machine the splines back on the input shaft to make it all fit together.

I have some measurements to take over the weekend of spline length etc, which once done should show if things fit together corectly or not.

Alex

adamnreeves · Post by **adamnreeves** » Fri Dec 15, 2006 3:24 pm

Yep, I think hacking the gearbox is a better solution to hacking the crank and limiting your future options.

v8alex wrote:The spigot housing is just the hole in the end of the crank.

I've spoken with Jim (jrv8) who mentions that it could be the gearbox (an R380 in my case) coming from a diesel vehicle. He has had to machine the splines back on the input shaft to make it all fit together.

I have some measurements to take over the weekend of spline length etc, which once done should show if things fit together corectly or not.

Alex

Post by **katanaman** » Fri Dec 15, 2006 4:18 pm

Ah that makes sense.

v8alex · Post by **v8alex** » Fri Dec 15, 2006 8:02 pm

OK, so please help me make sense !! Is the R380 input shaft essentially too long ? Preferred course of action either:

1. Remove a few mm of the rear of the crank ?
2. Remove gearbox input shaft and turning back the splines by a few mm on a lathe ?

Alex

adamnreeves · Post by **adamnreeves** » Fri Dec 15, 2006 8:06 pm

You need to take some measurements, I am not an expert here but I would not touch the crank:

a) crank is balanced
b) creating a future problem.
c) if you damage the crank it would cost more effort and time than the shaft I expect.

If jrv8 solution is to fettle the gearbox shaft and he knows what he is doing then follow his example.

v8alex · Post by **v8alex** » Fri Dec 15, 2006 8:56 pm

You're right. I do have some measurements to take that Jim provided me. I'll get round to this sometime over the weekend.