Maniacmechanic1
solid fixture here in the forum
Trapped hidden steam pockets in the cylinder heads are another issue in many engines.
TBucket Engine Project (Dart SHP)
- Thread starter Indycars
- Start date
Maniacmechanic1
solid fixture here in the forum
I think Rick was drinking again last night.
His last post.
He never mispells.
He is a perfectionist.
Maniacmechanic1
solid fixture here in the forum
Its like stepping in a line to buy Movie tickets.
Everyone is present Rick.
Everyone is present Rick.
busterrm
solid fixture here in the forum
Ya know Dorian,
I was looking at the retainer when Rick and I had the head off and one of the valve locks looked like it was deeper in the retainer and looked like it was also a slight bit cocked in the retainer. Before I left I was so curious how bad the valve was bent Rick and I took it apart, and low and behold the it was stuck and we had to jar it loose and back into its proper seat. Then the valve broke loose with the compressor. I am thinking when the valve touched the piston, that split second it was enough to dislodge the valve lock in the retainer.
I was looking at the retainer when Rick and I had the head off and one of the valve locks looked like it was deeper in the retainer and looked like it was also a slight bit cocked in the retainer. Before I left I was so curious how bad the valve was bent Rick and I took it apart, and low and behold the it was stuck and we had to jar it loose and back into its proper seat. Then the valve broke loose with the compressor. I am thinking when the valve touched the piston, that split second it was enough to dislodge the valve lock in the retainer.
replace the valve if its been bent, , you should easily see its ok or bent if you chuck the valve in a drill and spin it at low speed to see it or the valve head wobble,
before you install the new valve, hand lap the valve you replace it with,
measure the valve guide to valve stem clearance,
and before you install the new valve.
50% marvel mystery oil
and 50% crane moly lubes
coat both the internal valve guide and valves stem
http://garage.grumpysperformance.co...lve-seat-angles-and-air-flow.8460/#post-29682
http://garage.grumpysperformance.com/index.php?threads/how-to-lap-valve-seats.1159/#post-2362
before you install the new valve, hand lap the valve you replace it with,
measure the valve guide to valve stem clearance,
and before you install the new valve.
50% marvel mystery oil
and 50% crane moly lubes
coat both the internal valve guide and valves stem
http://garage.grumpysperformance.co...lve-seat-angles-and-air-flow.8460/#post-29682
http://garage.grumpysperformance.com/index.php?threads/how-to-lap-valve-seats.1159/#post-2362
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GREAT picture quality as always ,
THANK YOU RICK!
yeah, it looks like, you avoided major damage,
you'll need a new valve and some lapping time,
check the seal with alcohol in the combustion chamber,
not draining past the valve seal,
youll need too carefully re-clean and re-spray the copper head gasket,
and re-assemble and you'll be back up and running
yes you might want to have a local machine shop,
clean-up,inspect and install the new valve,
if you don,t feel comfortable doing the valve,
and cylinder head clean up, inspection, and reassembly.
THANK YOU RICK!
yeah, it looks like, you avoided major damage,
you'll need a new valve and some lapping time,
check the seal with alcohol in the combustion chamber,
not draining past the valve seal,
youll need too carefully re-clean and re-spray the copper head gasket,
and re-assemble and you'll be back up and running
yes you might want to have a local machine shop,
clean-up,inspect and install the new valve,
if you don,t feel comfortable doing the valve,
and cylinder head clean up, inspection, and reassembly.
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The gap was opposite the side of the spark plug hole so it made it hard to see. Also hard to get
enough distance between the camera and the valves to get a clear photo. I had the camera backed
out until it was in the spark plug hole. Just the situation didn't work out for the borescope.
Maniacmechanic1
solid fixture here in the forum
Its a Good idea I think Grumpy to a have a Pro Valve job done.
Rick Lapped in the valves once before building the engine years back now.
That way Precision Valve Angle & Valve Seat Angles are there again.
Maniacmechanic1
solid fixture here in the forum
At a Machine shop a Small Bore Dial Bore guage can be used to check valveuides ultra precise.
Down to 1/10,000 ths accuracy.
I have that small bore dial bore guage set.
Made in Germany. Very expensive.
Down to 1/10,000 ths accuracy.
I have that small bore dial bore guage set.
Made in Germany. Very expensive.
mathd
solid fixture here in the forum
Looking at the marks on the valve /piston and the curve..
Did you use a "home made" piston stop made of hard metal and screwed in too far? Maby it hit the valve and bent it?
I really can't see what else could have caused this.(unless you floated the valve because of that malfunctioning ignition box and rev limiter problem?)
note:its funny how the marks on the valve look fresh(looks like it was done not long ago).
Wondering what the valve seat looks like.
Did you use a "home made" piston stop made of hard metal and screwed in too far? Maby it hit the valve and bent it?
I really can't see what else could have caused this.(unless you floated the valve because of that malfunctioning ignition box and rev limiter problem?)
note:its funny how the marks on the valve look fresh(looks like it was done not long ago).
Wondering what the valve seat looks like.
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Maniacmechanic1
solid fixture here in the forum
Going to need to check all.
Cause still undetermined.
Cause still undetermined.
mathd
solid fixture here in the forum
It look like all the damage was done in only 1 or 2 hit.
Am i wrong to think that if the engine has run with a bent valve or floated the valves it will have many hit/damages marks(and probably carbon deposit/damages on some parts of the valve seat?)?
Would it show on the vacuum gauge?(i think Rick will have noticed)
Am 90% sure the cause is the piston stop
Am i wrong to think that if the engine has run with a bent valve or floated the valves it will have many hit/damages marks(and probably carbon deposit/damages on some parts of the valve seat?)?
Would it show on the vacuum gauge?(i think Rick will have noticed)
Am 90% sure the cause is the piston stop
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The first step was trying to find the compression stroke with my finger over the spark plug hole
and found no compression. Then I put the piston stop in to go ahead with determining TDC
after watching the valves to find the compression stroke. So the valve was already bent.
Well not exactly. When I put the valve spring compressor on the spring would not compress
so I could take the keepers out. It was the keeper that were jammed. The valve came out just
fine after the spring and retainer were off.
The heads are off to the machine shop tomorrow for clean up, a competition valve job, new seals
and check out the guide clearance. I'm taking them to Gerald Brand Racing, he has done work for the
Street Outlaws if that means anything. He also did the re-balancing of the rotating assembly after the
other shop screwed it up.
and check out the guide clearance. I'm taking them to Gerald Brand Racing, he has done work for the
Street Outlaws if that means anything. He also did the re-balancing of the rotating assembly after the
other shop screwed it up.
Loves302Chevy
"One test is worth a thousand expert opinions."
So what is the R/S ratio of your 1965 Olds 425? And do you figure a high or low R/S ratio is better for detonation resistance?
My 302 Chevy has a 1.9 R/S ratio.
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Loves302Chevy
"One test is worth a thousand expert opinions."
Make sure you tell the machine shop to measure each and every spring height.
They commonly measure 1 on each head and assume that the rest are the same.
Since your heads are new, it will probably work out that way anyways (same shim
thickness all the way across). The stack-up tolerances of your spring seats, retainers,
and locks can sometimes easily add up to .030", which means your spring pressures
will be all over the place.
You are a perfectionist, so I know you will not be able to sleep at night if it isn't correct.
I still think something went through your carb and intake (whether by accident or sabotage)
and got caught between the valve and seat on its way in. Then the piston smacked the valve
at that instant.
Are your head gaskets MLS or solid copper? If solid, you can re-anneal them in the oven.
Also, your combustion chambers are more "sooty" than I would expect. I don't think your
piston rings are fully seated yet.
They commonly measure 1 on each head and assume that the rest are the same.
Since your heads are new, it will probably work out that way anyways (same shim
thickness all the way across). The stack-up tolerances of your spring seats, retainers,
and locks can sometimes easily add up to .030", which means your spring pressures
will be all over the place.
You are a perfectionist, so I know you will not be able to sleep at night if it isn't correct.
I still think something went through your carb and intake (whether by accident or sabotage)
and got caught between the valve and seat on its way in. Then the piston smacked the valve
at that instant.
Are your head gaskets MLS or solid copper? If solid, you can re-anneal them in the oven.
Also, your combustion chambers are more "sooty" than I would expect. I don't think your
piston rings are fully seated yet.
Maniacmechanic1
solid fixture here in the forum
Mild detonation will cause Oily Sooty Residue in the combustion chamber & on the piston tops Mike.
The Piston Ring seal is being shaken loose literally.
What we are seeing.
Lots of crud carbon to clean up.
Maniacmechanic1
solid fixture here in the forum
About the same as a Pontiac 400.
425 Olds = 1.761 : 1. R/S ratio.
7.00" center to center length connecting rod.
3.9375" crank stroke.
Pontiac 400 = 1.766 : 1 R/S ratio.
6.625" Rod
3.75" Crank stroke
Pontiac 455 = 1.57 :1 R/S ratio
6.625" rod
4.21" stroke
Kenny Dutwiller experimented with Rod to stroke ratios in the 1980's in SBC engines.
Had a 11.0 Static mild cam engine running on 87 octane pump gas.
No detonation.
Have to find the article. Saved it.
How do you know what works & does not easy on Pump gas with a given R/S ratio ?
Trial & Error.
Real World Test Mike.
Maniacmechanic1
solid fixture here in the forum
http://www.purplesagetradingpost.com/sumner/techinfo/350 chevy engine.html
You already posted on Grumpys site here the same article Mike.
You already posted on Grumpys site here the same article Mike.
the cylinder heads look a bit greasy and dirty but in an expected condition,
that appears to be, at least visually,
reasonably good condition and the valve seats and bowls don,t show any appreciable wear issues,
A multi angle valve job may be helpful but I don,t think theres much in the way of repairs,
but as always check clearances and it would certainly not hurt to check valve spring load rates.
and while its hard to be certain it appears the engines running a bit richer fuel/air ratio than ideal,
due to the ash/crud on the piston domes, the runners free of similar crud.
That seems to indicate the valve seals and guides are in better than average condition,
but of course that engines very low mileage, so you would not expect much wear issues
that appears to be, at least visually,
reasonably good condition and the valve seats and bowls don,t show any appreciable wear issues,
A multi angle valve job may be helpful but I don,t think theres much in the way of repairs,
but as always check clearances and it would certainly not hurt to check valve spring load rates.
and while its hard to be certain it appears the engines running a bit richer fuel/air ratio than ideal,
due to the ash/crud on the piston domes, the runners free of similar crud.
That seems to indicate the valve seals and guides are in better than average condition,
but of course that engines very low mileage, so you would not expect much wear issues
Loves302Chevy
"One test is worth a thousand expert opinions."
Yep, that's the article. Based on that, if I ever build another SBC, I want to try a 377.
400 block (4.155" bore - 030 over) with a 350 crank (3.480" stroke), 11:1 static compression and running on pump gas.
400 block (4.155" bore - 030 over) with a 350 crank (3.480" stroke), 11:1 static compression and running on pump gas.