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Valve Guides

marksuxass

By marksuxass,
in Engines & Forced Induction

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r33_racer Grand Master

r33_racer

Posted
Posted

You can use 2P cast iron round bar as a good replacement material to make guides. Weve also made some guides from phosphur bronze which were currently using. However, the last set which was made by another machine shop wore out extremely fast like Daniel is saying.

Its weird how in some engines they wear out quicker then normal. Our midget engine uses phosphur bronze guides and its a push rod engine that revs to 8500rpm and has been racing for two seasons with no valve guide wear and being push rod its subject to more valve side loads then an over head cam valve....its my understanding that virtually all speedway engines run bronze valve guides and are mostly push rod. Our mates engine has run 4 years with bronze guides with minimal wear.

Weird!

bigmikespec Veteran

bigmikespec

Posted
Posted

Yes it is wierd, I am sure clearnaces between the stem and the guide would play a big part in it too. Just doing some reading I would rather use a bronze type guide for its heat transfer properties but not if they are wearing out quickly!

I asked Ferrea again about the seats but this is what they said about the guides. "a good manganese bronze or a copper bronze mix"

  • 9 months later...
bigmikespec Veteran

bigmikespec

Posted
Posted

Ok, digging up and old thread... going with a bronze manganese valve guide. How have guys gone using Supertech valve guides? Good product? Any issues?

Alternately may get NITTO valve guides but I cannot justify the price difference unless there is a good reason!

  • 4 years later...
MJTru Mentor

MJTru

Posted
Posted

Ok, digging up and old thread... going with a bronze manganese valve guide. How have guys gone using Supertech valve guides? Good product? Any issues?

Alternately may get NITTO valve guides but I cannot justify the price difference unless there is a good reason!

Sorry to wake up this old thread. But one of my stock motors rb26 just failed. Well let me start from the beginning. The motor came in a old r32 i had wit about 85k on the clock relatively new, but i know the owner and hes a guy that doesnt change oil on time and so when i got the car the motor had a spun bearing on number 3 cylinder. So i replaced l all the rods pistons with stock ones new rings and bearings new oil pump. The head o did myself and the only thing i didnt check was the guild clearance. Sad. I lap them myself as I've done this for years and all work well. Shim the buckets and all. The motor ran a cheap hoset hx35 wit l all ebay cheap stuff. Stock injectors and power fc.

It lived for 1 year. I was expecting the oil pump collar to fail but after opening it up i found one valve guild fails on the intake side one cylinder number 4 and i can see 4 more guilds have cracked. Its not to bad of a damage, but bad enough for me.

Question can worn giulds lead to them breaking. ??? Can fuel cut cause it.

Im now going to build it with a new head. I just cant get my head around what would cause it to fail. As its my first time experiencing a guide failure.

So you've pulled the head off and checked the guide clearance?

How much were the Nissan ones mate?

I just put brand new Nissan ones in. Pretty cheap.

mico Proficient

mico

Posted
Posted

Standard guides are dodgey and dangerous as, and brittle get rid of them. Ebay sells supertech guides for 264 bucks delivered can't go wrong. My guides leaked for years and I could never find why my car blew smoke but when the guides were removed they came out in pieces ....

mico Proficient

mico

Posted
Posted

Standard guides are dodgey and dangerous as, and brittle get rid of them. Ebay sells supertech guides for 264 bucks delivered can't go wrong. My guides leaked for years and I could never find why my car blew smoke but when the guides were removed they came out in pieces ....

HarrisRacing Proficient

HarrisRacing

Posted
Posted

This is true. 2 of my factory guides had chipped and broken off previously in my R32 (which had Rod knock when I bought it). As a mechanical engineer I see no issue with high strength / hardness aluminum bronzes. Remember not all bronzes are created equal just like not all cast irons are created equal.

BC guides I have used in past builds have had excellent performance for me personally. The mistu 4g63 as well as the Toyota 3sgte engines i built for my past racecars are both still living healthy lives after many seasons of racing. I would really have to spec an alloy for me to send the job to just any machine shop.

A bronze is an alloy of copper and other metals, most often tin, but also aluminium and silicon.

Aluminium bronzes are alloys of copper and aluminium. The content of aluminium ranges mostly between 5-11%. Iron, nickel, manganese and silicon are sometimes added. They have higher strength and corrosion resistance than other bronzes, especially in marine environment, and have low reactivity to sulfur compounds. Aluminium forms a thin passivation layer on the surface of the metal.

About BC guides:

RB26 VALVE GUIDES

BC premium valves guides are made from Manganese Silicon Aluminum Bronze alloy and CNC machined to exacting tolerances. BC guides are resistant to cracking and corrosion, while reducing friction and insures high lubrication even at elevated engine temperatures and rpm's. The perfect replacement to worn or damaged guides and 100% compatible with BC's lineup of stainless steel valves.

MJTru Mentor

MJTru

Posted
Posted

This is true. 2 of my factory guides had chipped and broken off previously in my R32 (which had Rod knock when I bought it). As a mechanical engineer I see no issue with high strength / hardness aluminum bronzes. Remember not all bronzes are created equal just like not all cast irons are created equal.

BC guides I have used in past builds have had excellent performance for me personally. The mistu 4g63 as well as the Toyota 3sgte engines i built for my past racecars are both still living healthy lives after many seasons of racing. I would really have to spec an alloy for me to send the job to just any machine shop.

A bronze is an alloy of copper and other metals, most often tin, but also aluminium and silicon.

Aluminium bronzes are alloys of copper and aluminium. The content of aluminium ranges mostly between 5-11%. Iron, nickel, manganese and silicon are sometimes added. They have higher strength and corrosion resistance than other bronzes, especially in marine environment, and have low reactivity to sulfur compounds. Aluminium forms a thin passivation layer on the surface of the metal.

About BC guides:

RB26 VALVE GUIDES

BC premium valves guides are made from Manganese Silicon Aluminum Bronze alloy and CNC machined to exacting tolerances. BC guides are resistant to cracking and corrosion, while reducing friction and insures high lubrication even at elevated engine temperatures and rpm's. The perfect replacement to worn or damaged guides and 100% compatible with BC's lineup of stainless steel valves.

Here is a question for you guys. I have a big build right now that i used a brand new cylinder head from nissan for. (NOT THIS ONE) But i didnt change the guides as the head was new. Here is the question do you guys know if the older oem heads and the newer one are the same guide wise. Did nissan upgrade the newer made heads with better guides than the older stuff. I would figure as time goes by the stuff would get better.

Also can you provide the part number for BC valve guides for rb26. I have a strong feeling im going to pull the new motor apart as i hate when guides fail, they do lots of damage.. i will also search for the bc part number im just wonder if yours and what i find will line up. Good info. Hats off to you mate.

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