2G Starter broke crank bolt loose?

[deflator]

I went to start it after a head rebuild due to 16 bent valves. Timing marks were perfect. The head is built, with supertech duals and FP3 cams.

No start. Got a loud clunk that sounded like it came from the head. I thought it was the drained lifters being loud, and it turned freely, so I kept trying to get it running.

After a few more tries, it would not turn over anymore. The crank timing mark was now off and the crank bolt was loose.

Valves look fine. Everything is coated inside with a mix of E85 and oil, with white goo in it. 5 gal of E85 was in the tank for ~6 months, diluted with 5 gal of fresh e85. I am going to drain it now, obviously.

I am suspicious of my cams, which were scored by a broken roller rocker. I cleaned them up but may have removed too much material in places. The engine turned oddly this build. On some strokes, it would get over the compression hump but then turn CCW a little? On others, it would rush CW once turned far enough.

It's hard to describe. But since it was pulling CCW in places, I feel something is wrong.

The roller rockers are not original now, and I can't be 100% sure the cam caps are in the right order. I haven't popped the pan off yet, but I should probably check the rods, rings, and bearings. The clunking was awful sounding.

 

[BogusSVO]

The cam caps should be marked with E for the exhaust side and I for the intake side

Then there will be a number.

I1 would be Intake side position #1 and holds the cam seal.

Are you sure you torqued the crank bolt?

 

[deflator]

The cam caps should be marked with E for the exhaust side and I for the intake side

Then there will be a number.

I1 would be Intake side position #1 and holds the cam seal.

Are you sure you torqued the crank bolt?

I even made a tool to immobilize the crank for torquing the bolt. This was put together a few years back though, so I can't be certain I put the correct amount of torque on it.

It happened twice in a row too. I didn't note that the bolt was loose the first time, just that the crank timing was suddenly off after trying to start it. I thought I just f'd the tbelt job, so I redid the belt, but it cranked over some and then skipped timing on the crank, again.

 

[BogusSVO]

Have you checked the balancer to make sure the outer ring has not moved?

A few spins on the starter should not allow the bolt to back off, unless it is finger tight.

Also check the key way in the crank gear, along with the woodruf key in the crank.

How are you checking when the belt jumps? Balancer and front cover? or back pate and front case mark?

 

[deflator]

The woodruf key isn't there! It must have not been installed...

The crank was down to ~40 ft/lbs of torque. Must have been enough to hold for a minute, then let everything slip because there was no key.

It still doesn't explain why the engine didn't turn uniformly, or the nasty clunk. Should I start looking for another used set of FP3s?

 

[BogusSVO]

Yeah it kind does....

Spring tension is enough to kick a cam one way or the other, and with no woodruff key, the crank gear can just spin on the crank snout.

Pull the cams, and run a leak down test.

 

[deflator]

Ah, so beefier springs were why it felt different to turn the engine by hand.

Seems this is the source of everything. Explains why timing jumped so badly the first time too. It was the first work I did when I got the motor many years ago and I screwed up it seems.

The head is already off, but I will buy a leakdown tester for later.

You suggested awhile ago that I send the cams to someone to get checked, but I lost the message. Which company did you recommend, delta?

 

[BogusSVO]

Yes Delta cams.

With the head off, and cams out, fluid test the valves.

http://www.dsmtuners.com/forums/newbie-forum/420313-how-fluid-test-4g63-cylinder-head.html

 

[counti41]

Crank bolt gets torqued to about 87ft/lbs i think send me your email address and i can send you the factory service manual.

 

[deflator]

I flipped the head upside-down and filled the CCs with alcohol.

2 started streaming almost immediately out the exhaust. I left it for an hour and one was empty, two were half empty, and one was full. The full one still had a trickle come out an exh. valve, but it took an hour. Only the ones that leaked immediately are a concern, right?

So I need 3 valves replaced. Where can I buy individual stainless valves? The guides are probably ok, since the bend is so minor. It cant cost much to have a shop swap out 3 valves

 

[BogusSVO]

Set it up and and fill the runner. mark the valve that is streaming, if it is just a drip , and not a stream .
Take a brass drift,and place it on the valve tip and wack it a time or three.

A solid whack, you want to open the valve a touch so the fluid can wash any carbon trapped between the valve and seat.

 

[deflator]

To check for false readings? Everything is new and clean. Never started just cranked.

I don't have any brass drifts, but I will test again, filling the runners this time. I can order drifts if this is an essential part of the test.

 

[BogusSVO]

I say a bass drift so you lessen the chance of damaging the valve tip.

You can use a 6 inch 3/8 drive extension if you are careful,

 

[deflator]

Ok, after filling the runners with pb, then tapping each valve tip a few times 6 out of 8 intake valves leaked. 2 were streaming. 2 were slower leaks but immediately apparent. The other 4 leaked a very small amount, and it took a 5 count for any pb to appear.

So, new set of valves. Guides probably ok?

 

[BogusSVO]

With the bend that slight, I would say the chances are better than even that the guides are ok.

I would pull all 8 intake valves and have them spun in a valve grinding machine to confirm the bent number.

 

[deflator]

Can do, but I just tested the exhaust side and 4 leaked, 2 badly. Roughly the same as the intake side did.

It's the engnbldr valves right? They are only 120 plus shipping so a new set is not a big deal.

 

[BogusSVO]

Yes, those are the ones.