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

rmchrgr said:

the guy driving the car won't know the difference whether there are a few small scratches in his valve guides or not

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My father-in-law uses a special tool set to recondition steel valve guides. You actually use a drill and force a nasty spiral groove in the guides all the way through (mind you, this is pretty specialized "nasty spiral groove", but still...). This, in turn, raises the metal up in ridges around the groove. The guide is then reamed to proper size.

The reason I mention this is it actually improves the guides because the spiral grooves hold oil and lubricate the valve stems (but no, it doesn't create an oil burning engine either). It works great and actually allows for tighter tolerances.

Bottom line is, as long as your scratches have been smoothed out, they won't hurt a thing.

hsorman said:

My father-in-law uses a special tool set to recondition valve guides. You actually use a drill and force a nasty spiral groove in the guides all the way through (mind you, this is pretty specialized "nasty spiral groove", but still...). This, in turn, raises the metal up in ridges around the groove. The guide is then reamed to proper size.

The reason I mention this is it actually improves the guides because the spiral grooves hold oil and lubricate the valve stems (but no, it doesn't create an oil burning engine either). It works great and actually allows for tighter tolerances.

Bottom line is, as long as your scratches have been smoothed out, they won't hurt a thing.

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Do NOT knurl bronze guides!!!!!!!! Ever heard of the saying "Out of the frying pan and into the fire"! DO NOT DO THIS! The knurling tool WILL break and then you are screwed.

Knurling reamers are for cast iron guides only, and IMHO, went the way of the Dodo bird. I do not knurl guides any more, and if a customer asked me to, I would refuse. If you have the head off and at the shop, do the job correctly, and not just band aide it.

hsorman said:

My father-in-law uses a special tool set to recondition valve guides. You actually use a drill and force a nasty spiral groove in the guides all the way through (mind you, this is pretty specialized "nasty spiral groove", but still...). This, in turn, raises the metal up in ridges around the groove. The guide is then reamed to proper size.

The reason I mention this is it actually improves the guides because the spiral grooves hold oil and lubricate the valve stems (but no, it doesn't create an oil burning engine either). It works great and actually allows for tighter tolerances.

Bottom line is, as long as your scratches have been smoothed out, they won't hurt a thing.

Click to expand...

Knurling cast guides. It was popular decades ago but does work. In school, we had a shaft with a small wheel which cut the groove. And of course, finish ream to size. Lisle tools used to sell a kit for cheap. I used it on my 340 heads and it did snug up the guides. Not a permanent fix though.

69Bee said:

Do NOT knurl bronze guides!!!!!!!! Ever heard of the saying "Out of the frying pan and into the fire"! DO NOT DO THIS! The knurling tool WILL break and then you are screwed.

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Yes, I'm talking about steel; I failed to mention this and will edit my post. But I was not suggesting he knurl his guides, just that a small scratch may hold some oil and this shouldn't cause any issues (unless it is a huge gouge, which does not seem likely).

hsorman said:

Yes, I'm talking about steel; I failed to mention this and will edit my post. But I was not suggesting he knurl his guides, just that a small scratch may hold some oil and this shouldn't cause any issues (unless it is a huge gouge, which does not seem likely).

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Cast actually. The post read as a suggestion to knurl, and I worried that the issue would get a lot worse. Yes, if the guides are ball honed, the scratches won't be too much of an issue, and would hold oil.

Ha, don't worry, no guide knurling will be happening.

I worked at a machine shop back in the early 80s, they used to knurl piston skirts & valve guides. I remember the owner telling customers that it was a short term fix. He would tell them it would only last about 30% of the normal life.

69 GTX said:

I worked at a machine shop back in the early 80s, they used to knurl piston skirts & valve guides. I remember the owner telling customers that it was a short term fix. He would tell them it would only last about 30% of the normal life.

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I agree. It's a temporary fix. Just a Band Aid. I sure would have liked to see a final ream to finished size on the guides in the OP's photos. If the manufacturing and machining is done right, you won't need to hammer the valves in and out nor should you need to file the keeper grooves so they don't peel metal out when you pull the valves. If things are right that won't happen. No wonder why it's recommended that you send your new $1500+ aluminum heads to the machine shop to be corrected before you run them.

snakeoil24 said:

You get what you pay for!

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I've had three sets of Stealth heads and have had no problems. I've built engines with other heads, Edelbrock and Brodix that had to go back. Sometimes it's not the price, it is the luck of the draw.

rmchrgr said:

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.
View attachment 1076217

Note brass shavings under top of keeper grooves.
View attachment 1076218

Note the scratches in the guide.
View attachment 1076219

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.

View attachment 1076222

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

- Greg

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I'd contact 440 Source, I've found them to great at standing behind their products.

Hi Rmchrgr- I can help if needed,i am in Branford, not too far from you. Rogers Auto Machine. 203-488-6532 Mike

Thanks for the offer Mike, good talking with you today.

So I think we're going to leave everything alone for now. Not too concerned about the guides beyond cleaning them with a brush before final assembly. We plan to run it on a stand before putting it in the car. If there are any issues hopefully they will make themselves known at that point. Not much we can do after that.

It's been suggested to me that the manual spring compressor we used could be what caused the burrs in the keeper grooves. Makes sense especially if it's a little tough to operate the tool. I'll take all the credit for blowing through the roadblock of the valves hanging up and forcing them out before dressing the edges.

Regarding the gouge - after talking it over with my friend, we've kinda figured out how it happened. That spring compressor I have can be a little bit of a bear to operate. I did the first head and then handed it over to my friend to do the second one. (We marked them 1 & 2, the head in question is #2) He'd done this operation once before with the same tool on a set of stock iron heads with lower spring pressures than what comes with the Stealth heads however, it was a bit of a struggle for him this time. But that's how we've been doing this entire project - I show him how to do something once or twice then he does it so he can learn how to do it and/or screw it up himself.

Anyway, I got it ready for him and went to do something else not really paying attention to what he was doing. From what I remember, I did hear him fumbling around and cursing at one point so it must have slipped off the valve and caused the gouge. Unfortunately, I don't think he realized what happened nor did I bother to go over and check what he was doing. That was the last thing we did that particular day so once he was finished he put the head back in the box. I never even saw it or I would have said something right then. Not throwing him under the bus, **** happens, could have happened to anyone.

Guess learning the hard way is better than not learning at all.