I'm pretty sure too it has a wiggle. I remember one of them having a little wiggle when I replaced the valve springs with Schneider springs.
All Small Six Checking for Air Leaks
- Thread starter StarDiero75
- Start date
This relates to all small sixes
frozenrabbit
Well-known member
That's a valve spring compressor to use with the rocker shaft installed.
You might have a bent valve, air is getting past the seat, before it comes out the guide. Even with a bad guide, the valve should still seal. A bent valve would wear the guide pretty quickly.
Shouldn't have to let it set overnight, you should be able to tell right away, especially with that much air leaking past it.
You might have a bent valve, air is getting past the seat, before it comes out the guide. Even with a bad guide, the valve should still seal. A bent valve would wear the guide pretty quickly.
Shouldn't have to let it set overnight, you should be able to tell right away, especially with that much air leaking past it.
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You should have put compressed air into the cylinder before you pulled the head.
Put the piston at TDC, apply compressed air to the cylinder and listen for a leak.
To use the KD-915 with the head on you would put the piston at TDC then apply compressed air to the cylinder.
You could have figured out the if a valve was leaking without pulling the head.
+ gas won't detect an excessively worn valve guide.
You would have a good chance of being be fired in an auto repair shop for pulling a head to do gas leak check on the valves.
Customers don't want to pay for unnecessary work.
Since you already had the off I see why you were given that advice
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That's why I said: "
"Mount the rocker on the head then use a KD-915 to remove the spring."
If you read the whole thread the author was checking for a vacuum leak which could be caused by an excessively worn intake valve guide.
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This is fun. Gotta build a test plate for the exhaust too. Also found out, he never milled the head the .070 I had asked. Just .010. I CC'd the chambers and got 56.25 as an average. It was supposed to end up at 49cc. So I've been running 8.3 SCR and 7.0 DCR. I'm pretty pissed. I always thought it felt weak despite the work done.
frozenrabbit
Well-known member
Looks like a not-so-good head job. That cast spot on the edge of your head between 3 and 4 on the exhaust/intake side is kind of a 'safe' machinable depth indicator for the head. Looks like there's still alot of material. If they didn't do what you asked, I doubt the valve cut and guides are much better.
Can you pull that most leaking valve from your air leak vid, and post a good photo of the head seat and the valve seat surfaces? Should be an even contact width all the way around the seats. If the guides were bored off angle, the seats should show it.
I wouldn't waste any more time on testing, it's not right.
Can you pull that most leaking valve from your air leak vid, and post a good photo of the head seat and the valve seat surfaces? Should be an even contact width all the way around the seats. If the guides were bored off angle, the seats should show it.
I wouldn't waste any more time on testing, it's not right.
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Well now you know that when you were trying to tune it to run right and all along you were fighting against some sub standard workmanship too. Sorry 
frozenrabbit
Well-known member
Is this also the head you had your EFI setup on?
My brother took a grooved main 406 FE crank in to the local machine shop to be turned.
They stamped the invoice # on the crank.
When he went to pick up the crank they tried to give him a 390 crank without grooved mains with the invoice # stamped on it.
My brother said "that;s not my crank, it doesn't have grooved mains.
The counter guy said "maybe they turned the crank until there were no grooves.
My brother said: It doesn't have the same casting number as the crank I brought in.
On my brother's return visit he told the counter guy: "I want my crank or I am going to kick some @ss."
My brother got a phone call saying they found his crank.
Their excuse was the bailing wire fell off and they found it in the bottom of the hot tank.
They stamped the invoice # on the crank.
When he went to pick up the crank they tried to give him a 390 crank without grooved mains with the invoice # stamped on it.
My brother said "that;s not my crank, it doesn't have grooved mains.
The counter guy said "maybe they turned the crank until there were no grooves.
My brother said: It doesn't have the same casting number as the crank I brought in.
On my brother's return visit he told the counter guy: "I want my crank or I am going to kick some @ss."
My brother got a phone call saying they found his crank.
Their excuse was the bailing wire fell off and they found it in the bottom of the hot tank.
Yes sir. Once I make sure its good and the carb runs it well, I'll swap it back to the EFI again. Hopefully this time it'll work lol.
2 years and hundreds of hours.... wasted.... I've grown now and know not to trust anyones work. Always double check. My checks here will be standard for heads from now on.Well now you know that when you were trying to tune it to run right and all along you were fighting against some sub standard workmanship too. Sorry
So far as I can tell, only 1 guide is leaking air. I'll replace it and check again. Current plan is a friend of mine from work is gonna help me replace the guide, then lap all the valves to seal. Afterwards we'll evaluate if the rest of the guides need replacement.
I would like to test the exhaust but part of me just wants to replace all the guides based on this being crap.
I got another guy at work thats gonna help me deck the head down. I gotta get the CC's down to about 46cc to bring my SCR to 9.47 and DCR to 7.99. How does this sound?
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They were nice when I came back to get my aussie head. However I didn't actually go into all this. Figured it was wasted breath. Got my buddies 390 he was giving me and my aussie and got out. Good news, according to them the aussie mag'd great! Howerver what does that mean coming from them.....
frozenrabbit
Well-known member
Check the stem on that worst valve, even the slightest warp is bad.
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About 30 years ago I noticed that when entering a certain machine shop their cabinet displays were full of high quality engine parts.
I thought that I would receive those quality parts.
When I picked up my machined 200 block and crank the bearings and rings were white box no label parts.
One I started the engine it only had 12 lbs of oil pressure at idle.
All the bearings had an excessive margin and it was obvious they were defective for other reasons.
After arguing with the machine shop owner and machinist and showing them one set of defective rod bearings they ordered me Federal Mogul bearings.
I replaced the rod and main bearings without pulling the engine.
With the new quality bearings the oil pressure at idle went to around 45 lbs.
The machine shop owner had wanted me to bring in all the old main and rod bearings in before they gave me the new bearings.
I convinced him that there was no way I could do that with the head on and the engine in the vehicle.
I thought that I would receive those quality parts.
When I picked up my machined 200 block and crank the bearings and rings were white box no label parts.
One I started the engine it only had 12 lbs of oil pressure at idle.
All the bearings had an excessive margin and it was obvious they were defective for other reasons.
After arguing with the machine shop owner and machinist and showing them one set of defective rod bearings they ordered me Federal Mogul bearings.
I replaced the rod and main bearings without pulling the engine.
With the new quality bearings the oil pressure at idle went to around 45 lbs.
The machine shop owner had wanted me to bring in all the old main and rod bearings in before they gave me the new bearings.
I convinced him that there was no way I could do that with the head on and the engine in the vehicle.
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At this one shop I worked at this Honda came in that was getting water into one cylinder.
Another mechanic pulled the head and had it sent to his favorite machine shop to be pressure tested.
The head came back pressure check OK and of course they charged for their work.
The other mechanic reinstalled the head.
Water was still getting into the same cylinder.
The other mechanic pulled the head again.
While looking closely at the combustion chamber I noticed a tiny hole. I stuck a fine wire into the hole.
It went into the water jacket.
The machine shop was told about the hole in the combustion chamber.
The machine shop was stupid enough to call us and ask for the old head gasket so they could make a pressure tester!
The hole in the head was welded up and the head was reinstalled.
Another mechanic pulled the head and had it sent to his favorite machine shop to be pressure tested.
The head came back pressure check OK and of course they charged for their work.
The other mechanic reinstalled the head.
Water was still getting into the same cylinder.
The other mechanic pulled the head again.
While looking closely at the combustion chamber I noticed a tiny hole. I stuck a fine wire into the hole.
It went into the water jacket.
The machine shop was told about the hole in the combustion chamber.
The machine shop was stupid enough to call us and ask for the old head gasket so they could make a pressure tester!
The hole in the head was welded up and the head was reinstalled.
Did you have them do work on the Aussie head beyond magging it, or did you go retrieve it before they did, based on this experience?
Oh no they hadn't started work on it yet. Only magging. Thank god I found out all this before letting them touch ut
Westbay Machine Shop, Bremerton, WA.
