I was wondering on guides too. I am pissed as I have a head in the shop that the machinist went and knurled the guides. It hasn't been run yet. I was taught knurled was better back when I was in college in auto shop.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

In my experiences with this matter having worked in a first rate racing machine shop for almost 20 years, I can say that we never used anything but bronze guides and/or liners in all heads, cast iron and aluminum, and never had any failures related to them just because they were bronze! Only improper techniques and over-sites of the person doing the job were the culprit if and when an issue was suspect, and that was only 2 or 3 times in the entire 20 years I worked there. We were a pretty high volume shop. I personally will never use anything but bronze guides or liners in anything I ever build whether it's a race engine or street engine. If anyone else has also experienced any failures it's from operator error in machining and not the fact its bronze.

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There's no such thing as too much cam....only not enough engine!

The nut behind the wrench can cause a lotta problems!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Knurled guides are OK for Gramma's six cylinder Nova that never gets driven over 40 MPH, but on anything else, they suck.

I used to have this argument with a buddy who ran a shop with his Dad. They swore by knurled guides, and I despised them. I even showed them a set of stock 340 J heads that they did and I tore them apart with less than 2000 miles on them.

About 5 years later the guy told me I had been right all along. His Dad was just old fashioned and didn't want to buy any new guide tools.

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Official Cookie and Mater Tormentor.

I had guides knurled once and one of them pounded out in about 6k miles. Never again.

Lou

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Home of Slant6-powered fun machines since 1988

Yep, knurling was popular when cars didn't get driven too many miles a year. Remember, in the '50's-'60's a car with 100K miles on it was considered junk.

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Official Cookie and Mater Tormentor.

The ones in my Super Bee were knurled. I put 45K on it and never had a problem.