Fwiw I decided to use the sintered steel guides when I had my head work done last month. I considered the bronze manganese guides but decided on the steel guides based primarily on the fact that there is more history and data points with steel guides then aftermarket. For example, when I hear people like Dave Helms say that they have never seen guides fail on a 360 even with 100k+ miles it's meaningful info. There are fewer cars using the aftermarket bm guides so there is less long term data. They are probably fine but you can't argue with the well documented longevity of ss guides. As to the risk of ss guides "dropping" because of no flange, I have never heard of that happening when the machine shop uses the factory install tool which ensures the correct press. If your machine shop doesn't have that tool, then you might run that risk. Finally, the fact that bm guides are used in race engines means nothing to me; race engines are routinely torn down and rebuilt so longevity is not an issue.
I was very surprised to hear it from him and also the head builder he recommended. I forget what he said varied, but if I had to take a guess, valve height. Variation of 1-2mm. I immediately spoke over the phone to the head builder he recommended. A company located in San Diego. I can't remember the name right now but he did verify it to be true and said he would measure the stock guides and order matching ones from CHE. How important is it to order matching specs vs WSM guide specs, i really dont know. Did you measure to see if the OEM guides you removed varied in size?
Just great. Another thing to make sure done correctly when installing the guides. I also read somewhere the assember working with pm sintered steel guides needs to make sure he applied adequate and the proper lubrication.
No they are not. Many places use the part number so it's for a 355. My bronze manganese 355 guides came from GT Car parts. It's not a mystery just use the best product you can get. FYI When I started my valve guide adventure, about a year ago I was looking at the steel guides from ferrari. The best price I found at the time was with ferparts you probably have seen them on ebay. Anyway he couldn't source both intake and exhaust guides. I was told that ferrari was stopping the production of the steel guides. I also saw the price of these go through the roof. ridiculous to pay that kind of money for half the guides when for a little bit more cash I got the complete set of intake and exhaust guides in the superior guide materials. Vist me just under $700 for guides and seals. No vales or other parts needed to be changed.
"half the guides"? What are you talking about? BM guides might have slightly better heat conducting capability but with all due respect us weekend drivers would never know the difference. What matters is a long history of reliability and longevity which SS guides unarguably have. Maybe you can point me to the hp gains associated with BM guides
Yes that was for my experience sorry for any confusion, I could only source half of the guides at the time and went with my machinists recommendation and others here about using the BM guides. I trust him and his knowledge. Defiantly cheaper than the SS guides. I couldn't see paying $40-50 each for the steel guides. And it was difficult to see who actually had ferrari steel guides vs something I didn't know what where and how they got it and the wanted the same price.
Sorry it's taken so long for a reply! Yes, once I received the CHE guides I measured all of the dimensions against the original guides, and any difference (if any) was minuscule. I was mainly interested in the OD, to ensure that there was enough interference for proper fit in the cylinder head, and ID to ensure I would be able to hone the guide for proper valve/valve guide clearance.
That's good to know. Thanks for the heads up. I've been thinking about this. I retract my statement about it costing $10k to replace guides. It would cost $10k if they were completely failed and you needed it done right away. Pull motor + belt change $4-6k. I was quoted $2500 to do headwork and that includes the CHE guides. However, that price does not include the labor to pull off the heads and reinstall nor does it include new Valves. $500 for 40 CHE guides. Vs $1800 ($45 each) for 40 OEM Sintered steel guides. $1400 difference. This is money that could be spent on new valves. The likelyhood of the CHE guides failing soon is slim. And by the time they do fail, if they fail, it should be around the time for a belt change anyways, so it's prob not fair to factor in the cost of pulling out the motor to redo the heads. Assuming labor to pull the heads, redo them, and reinstall is $3000, youre only out about $1600 compared to if you had purchased steel guides (assuming they do last longer) and you have brand new MB guides. This is 75-150k miles later.
