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New heads - I screwed up the guides and gouge in surface?

rmchrgr

rmchrgr

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Working on a set of brand new 440 Source Stealth heads. The valve guides seem excessively tight.

The heads were disassembled to be checked before installation. Unfortunately, the valves were really tough to get out just by pulling them. When they finally came free, there were brass shavings coming out. It appeared like the top of the keeper grooves were actually cutting into the guides. Getting them back in required a good smack with a soft mallet.

Brass shavings.
IMG_1317.JPG


Note brass shavings under top of keeper grooves.
IMG_1318.JPG


Note the scratches in the guide.
IMG_1320.JPG


Not sure if this situation is really bad, normal or somewhere in between. Never had this happen to me before so I have no point of reference. I'm thinking it can't be great. Obviously you don't want loose guides but given that the heads will expand, I'm thinking the valves are going to stick and/or get burned up.

So if this needs to be fixed, whats the approach?

Second issue - this seems to have happened while handling the heads, not really sure how but there is a pretty good gouge/scratch in the head surface. You can definitely catch a nail on it. Thinking the edges should be smoothed over with Scotch Brite but that's it? Hoping the head gasket will seal this up, using Fel Pro 8519-PT-1.

IMG_1321.JPG


These heads are going on a fairly mild 438" stroker, 100% street driven. Thanks for any input.

- Greg
 
NFG Greg!!! Valves should NOT be that tight in the guide. Did you verify spring pressure to match the cam?? Did you check the valves on the seats?
 
HEMI-ITIS said:
NFG Greg!!! Valves should NOT be that tight in the guide. Did you verify spring pressure to match the cam?? Did you check the valves on the seats?
Click to expand...

Yes, the springs are matched to the cam from Hughes where we bought it. It's a pretty mild hydraulic flat tappet, 228/232 @ .050. We didn't really check seat concentricity yet, we just took them apart to check them right now. Specs for the springs are 1.880" @ .550" lift. When checking installed height we got the 1.880" but only at .5485" or so not totally perfect. I don't think that's the issue though since this happened right out of the box.
 
The keepers, especially with strong springs, will burr the edge of the groove on the valve and this is why they shaved the brass guides when you removed the valves. I usually will use a file to dress the grooves to prevent this before I remove the valves. A valve guide ball hone should dress the scratches and hone to get a little more stem to guide clearance. Check to see if the scratch is inside of the gasket, and if it is, don't worry about it. If it is outside of the fire ring, no real need to worry about it, but if it crosses the fire ring, have the heads surfaced to just clean them up.
 
Also, it would be best to find a shop that uses a "Diamond" cutter to mill heads, and not carbide, abrasive belt, or other old fashioned method. These are aluminum heads I have cut using a diamond cutter.


IMG_7944 (2).jpg
IMG_7947 (2).jpg
 
69Bee said:
Yes
Click to expand...
As a youngster I tore down and assembled 100s and 100s of those. My dad owned a machine shop...we did only heavy industrial (Caterpillar, Mack, Cummins, Detroit, etc.), except the MGBs. We had a contract in the 1980s with an outfit in Seattle that would send them to us by the pallet full. They were all cracked in the combustion chamber, some up into the guides. Dad furnace brazed them, no arc, with a nickel/iron rod, oxy/acetylene, then we machined them, etc. Obviously those were cast iron...yours aluminum?

Thanks for the memory jog!

HiJack over, thank you.
 
69Bee said:
The keepers, especially with strong springs, will burr the edge of the groove on the valve and this is why they shaved the brass guides when you removed the valves. I usually will use a file to dress the grooves to prevent this before I remove the valves. A valve guide ball hone should dress the scratches and hone to get a little more stem to guide clearance. Check to see if the scratch is inside of the gasket, and if it is, don't worry about it. If it is outside of the fire ring, no real need to worry about it, but if it crosses the fire ring, have the heads surfaced to just clean them up.
Click to expand...

Thanks. Was thinking the keeper groove would need to be dressed but I'm not sure with what.

And yeah the gouge is definitely inside the fire ring so yeah, duh, no gasket will seal that up since there is no gasket there... Doubt our local shop has a diamond surface cutter, may not even be able to do it himself, probably sends it out.
 
From what I've heard and read, Source heads (and others) are known for poor valve stem fit & questionable valve concentricity out of the box. I've had the issue with lock groove developing an edge after extended use with my high spring pressure roller cams. If the valve doesn't just drop out after removing the valve seal, I take the small file and manually rotate the valve around to trim any ridge.
Get the heads milled to remove the gouge.
 
Last edited:
When I installed aluminum heads a few guides were tight. Brought them to a machine shop to just "touch" the tight ones. Picked up the head and now it was too loose:drama::mad:
Brought them back again and they installed 2 new guides on their dime.

OIPg.jpg
 
I am going to suggest that there is NOTHING wrong with the Valve guides..... only your dis-assembly procedure.

Once the Heads are assembled, it is not uncommon , and usually typical of the stock 7* V/Locks that "Burrs" develop on the upper V/Lock groove in the Valve.... as usually the Valve tops get tapped with a dead blow hammer upon assembly to ensure seating of the Locks....resulting in Burrs.... and which to then dis-assemble correctly requires use of a small file to remove.
DO NOT "force" anything !
Spin/rotate the Valve with one hand while carefully filling with a small flat file that transverses the entire groove on both sides(Nail file with suffice) in the opposite direction with the other hand to remove the Burr BEFORE removing the Valves !

You have now successfully damaged your V/Guides by NOT knowing what the heck you are doing ?
and,
actually "measuring" the V/Guide Clrc ..... requires a Micrometer to measure the V/Stems.... then transfer of that dimension onto a small dial bore gauge as "zero" to then go in the guide and measure the clrc ?

How are YOU measuring the V/Guide clrc to then declare them TOO TIGHT ?
by a RIP/TEAR/FORCE test with Burrs on the V/Stems before actually NOT filing the Valve Lock groove BURRS and then damaging your V/Guides ?

Because that doesn't mean the V/Guides are TOO TIGHT.... it only means you tore up your guides FORCING Burrs through them ?
 
Last edited:
As has already been said........ the reason the valves don’t come out is from a burr that’s been raised on the upper lip of the keeper groove by the stamped locks.
This is not a 440 Source thing.
It’s the same for any head with stiff springs using stamped single square lock groove style locks.
Having to file off the burr on the valve before sliding it out of the guide is SOP.

If the heads use machined locks instead of stamped, the burr usually doesn’t occur.

Many budget oriented heads use stamped locks.

The typical ootb guide clearance on Stealth heads is about .0020, which is plenty.
 
Last edited:
Glad you brought this up about LOCKS!
We have used 10 degrees Locks for ever.
But Hughes are saying you should use 7 degree locks now???
The 7 degree locks always damage the valve stem, especially with stainless valves...
Folks don’t know this and ‘whack out’ the valve and wreck the soft guides...:screwy:
 
polyjohn said:
Glad you brought this up about LOCKS!
We have used 10 degrees Locks for ever.
But Hughes are saying you should use 7 degree locks now???
The 7 degree locks always damage the valve stem, especially with stainless valves...
Folks don’t know this and ‘whack out’ the valve and wreck the soft guides...:screwy:
Click to expand...

I don’t ever have a problem with the lock grooves when using 7 degree locks that are machined instead of stamped.
 
PRHeads said:
As has already been said........ the reason the valves don’t come out is from a burr that’s been raised on the upper lip of the keeper groove by the stamped locks.
This is not a 440 Source thing.
It’s the same for any head with stiff springs using stamped single square lock groove style locks.
Having to file off the burr on the valve before sliding it out of the guide is SOP.

The typical ootb guide clearance on Stealth heads is about .0020, which is plenty.
Click to expand...


Yep.... we see lots of Stealths, typically plenty of V/Guide Clrc. ?

Seems to me.... this unfortunate occurrence is to some extent how bad reputations get proliferated for many products/vendors ?
just say'in....
here we have IMO, a case where "inexperience" has unfortunately resulted in a thread that is in fact TITLED.....
Stealth heads - valve guides too tight and gouge in surface?
which,
many, many, many people will merely glance over quickly without reading further and set in their minds a "problem" with STEALTH Head V/Guides.....
when in fact NO PROBLEM EXISTS ?
 
rmchrgr said:
Thanks. Was thinking the keeper groove would need to be dressed but I'm not sure with what.

And yeah the gouge is definitely inside the fire ring so yeah, duh, no gasket will seal that up since there is no gasket there... Doubt our local shop has a diamond surface cutter, may not even be able to do it himself, probably sends it out.
Click to expand...
I use a file...
 
OK lesson learned about dressing the keeper grooves before popping out the valves and realize now it's not a quality issue. I told my friend that I am "helping" build this motor that I would eat that repair since it was a error on my part. Just never thought to do that. I feel really bad about it.

I still would like to have the question answered about how to dress the keeper grooves before taking the valves out? What should be used?

On the gouge - I really have no clue how that could have happened. Looking at it from a cost perspective, I think it will be easier to buy a single new head rather than taking them somewhere to have guides and surfacing done to both heads.

Anyone want to buy a single Stealth head that needs the guides cleaned up and has a gouge in the surface? :(
 
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