Bronze Manganese Valve Guides

If you are referring to OEM vs OEM, the newer sintered steel guides should last much longer. However, after-market bronze manganese guys offered by reputable guide makers should be good. I wouldnt put OEM bronze guides back in that's for sure.

 

I agree with Ken.

That "R" at the end of the Ferrari part numbers means it is a "Reproduction" and not the OE Valve Guides that came from the Factory.

These were most likely purchased from Ricambi who at one time carried/offered some which Gary(Enginefxr) made and were listed as 176437R & 176438R.

Maybe Daniel can explain the valve guide material specifications for these reproduced parts.

 

my car had the Valve guides done in 2009.. as per the records i have..
the shop that did the work used the Bronze Manganese guides.
no issues since..

I purchased the car Sep 2014.. and it passed a compression test with strong level numbers across all cylinders..

 

heres a pic just for visual differences, that I found in the past while doing research on the same topic.
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If they came from Gary. Run. Run far away.


This is an interesting write up on valve guide history:

ferrari cylinder head porting custom valves valve guides

 

I don't have a clue as to what shops and other parts suppliers do with PN's on non OE Ferrari parts.

I was just recalling what I knew was being done with Gary and Daniel back at one point in time.

There is nothing wrong with manganese bronze guides if the right alloy is used and they are properly installed....we ran most all of our Porsche race engines using a proprietary manganese bronze alloy and had a lot of success.

 

As long as the new guides have the keeper to hold them in place. Seen a few guide drops for guides without the keeper in place
I don't even think you can find a bad new guide for sale anywhere today, it's 2015

 

Manganese bronze guides are superior to steel in regard to heat transfer and lubrication. They are not as hard but still much harder the OEM guides. The OEM bronze guides which appear copper color appear to be phosphorous bronze with is very soft.

 

Using the factory part number with an "R" is very common practice and means nothing as far as the source.


I have used manganese bronze guides in many 355s and their performance has been excellent.

Factory guides have never been good no matter the material used. I have never used a factory guide except when forced to do so by Ferrari in warranty repairs.

 

Brian, my car (1998 355F1 Spider) is in for a major service now. I suspect some issues.

In prep for what I suspect will be a top overhaul, my research suggests a manganese bronze guide. In your opinion is there a better source than others for these guides?

 

this ^^^

Don't get wrapped around the axle thinking you need STEEL.

Bronze Manganese is what you want in your car.

I had my heads done by a gent that works on a lot of 50-60s Ferrari Engines. Guess what he uses in those motors?

The cost of the Steel guides is also higher than it needs to be by about $30 a guide.

Bronze manganese guides for my 355 was around $12 a piece.

 

I honestly can't say. I been messing with the 355 only a 3-4 years but everything I seen since the 80's done had a keeper unless it was some dumb ass design that required none due to a an even more retarded valve seal design.

 

After reading all of the posts on F Chat about valve guides and reading up on valve guides in general, ended up with MN Bronze guides from CHE Precision (cheprecision.com). I had a very good conversation with Claude (the owner/founder) he is very knowledgeable when it comes to valve guides and metallurgy. I'm in the process of installing them now.

 

Hey Randy thanks for the thread on engine out used yours and others when i did mine. Dont see you on here or the other site much. Anyway thanks.

 

These days I use a machine shop I trust and leave it up to them.

 

I certainly agree with Brian. A trusted machine shop is probably the best way to get the job done quickly and with some peace of mind. Unfortunately, my personality ( that I inherited from my father) won't allow me to let anyone work on my cars. LOL!! So, I removed the old guides and inserted and honed the new guides myself. Took a while, but I was able to get the valve stem/guide clearance right where i wanted it.

 

I spoke with Claude as well for about 30 min. Cool guy. Reputable company. Let me guess... When he compared a PM Sintered Steel guide to his MN Bronze guides, he mentioned cutting in half a steel guide to find they are very porous inside correct? I believe him. Itis also confirmed throughout the net that PM sintered steel guides are porous, but that doesn't necessarily mean it could possibly be weaker than his MN Bronze guides, which is what he is implying. The porosity of the steel guides helps in sustaining much needed lubrication. So basically it comes down to this. Steel is stronger than Bronze, but Bronze guides have no porosity, so it might havd better structural integrity? Or the porosity in the steel guide is not enough to prove it to be overall weaker and only aids in lubrication. Bronze metal is inherently a better lubricating and heat transfering metal. The peformance difference in the two is most likely marginal considering our application. Perhaps one guide lasts 175k mi and the other guide last 150k mi. Miles most of our cars will not see anytime soon to draw a conclusion. MN Bronze guides and especially ones from CHE precision have been used successfully for years, however, i believe our cars have thinner guides because we're 5 valved, whereas 99% of the industry is 4 valved? I would place my bet on the stronger metal Ferrari chose. Sintered Steel is also more expensive to manufacture. The cost difference between the two isnt nearly as much as the $10k cost to pull out the motor and redo the heads in the case of a failed guide. For resale value, id put in sintered steel simply because new buyers like to hear "new upgraded Ferrari steel guides..." The word "bronze" would probably scare most new buyers not in the know.

However, one thing that is suspect about the OEM sintered steel guides is the lack of "bump" to prevent walking. Why did they have the bump in the earlier copper design and not the later steel design?

 

Claude also mentioned the guides he had vary slightly in measurement. He said the guides in our motors are not all exactly the same and the head builder's responsibility is to take proper measurements and order the correct/matching spec guides.

 

CHE Precision. No need to look elsewhere for MN bronze guides. They stock them and they work closely with several head builders.

 

Perfect. Thanks brother.

I'll know more in the coming weeks after the leakdown test prior to the engine out.

 

I think some are mistaking the original 'bronze' guides as being the same as the modern replacement bronze guides, which are of a different composition and much much better. The OEM guide composition was just 'soft' by comparison to pretty much anything.

 

Hi Ken! Not doubting what you're saying by any means, but when I first got in touch with CHE, I asked if they made guides for an F355 and they replied "yes". CHE indicated that they sell them "all the time " : ). He did confirm all of the measurements that he had were as stated in the WSM. Here's a couple of pictures of the guides. Anyone interested will notice the difference between exhaust and intake guides (shape) and also notice the correct shoulder that interfaces with relieved portion of the head. Also a picture of them installed. When i received them, I double checked all dimensions and they were spot on.
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