rb25det valve guides

[DRIFTER]

are worn exhaust valve guides common on these engines?

[StockyMcStock]

when my head was taken apart the idiot bashed the 12 inlet guides out with a punch and rooted them beyond belief. all the guides had a bit of wear but were still fine to use, the engine had done 100,000km or so i believe. if you have to replace them with new ones, there's a trick.

new from nissan they are $90 each or something stupid like that. aftermarket ones do not exist (at least, my engine parts stockist could not get them) but we measured em up and found:

OD: 10mm

ID: 6mm

Length: 38?mm can't remember exactly.

anyway turns out the CA18 uses exactly the same measurements, but the guide is physically longer. buy 12 of them for $100 or so and lathe the ends off to bring the length down. works a treat!

[DRIFTER]

thanks

[R32-GTS]

worn guides common on rb26dett , not so bad on rb25 and rb20.

[SteveL]

Get a quote from a local engine reconditioner to have the guides k-lined, which is a bronze insert used after the valve guide bore is reamed oversize. Usually cheaper than new guides, plus has better wear characteristics.

But before you do anything, have the valves measured for wear as well as the guides if there's cause for concern.

[ovabooster]

any idea as to how much for k-line guides? Tomei are bot $500. Just wana compare prices

cheers

[proengines]

I won't k-line these heads, they don't last. Use CA18 guides as described above. heat the head to remove them and heat the head and freeze the guides to install them. The only time i've seen guides worn is where they have had k-lines fitted, I've also seen a CA18 head where the guide has come loose. K-lines have their place, just not in these engines.

[2rismo]

What are CA18 guides worth and where can I get quality ones from quickly and cheaply?

[N1GTR]

Wouldnt nengun have them?

Or Hi octane? or Rocket?

[N1GTR]

At least the last 2 would be able to offer overnight delivery if they're in stock

[2rismo]

Nothing at Rocket - waiting for a call back from one of the boys at Hi Octane. I called them to start with but they said that all they kept in stock were the Tomei Beryllium ones and there's no way known I'm spending 700-plus on valve guides.

[drgnball34]

does anyone know if the r33 valve guides also fit the r34 NEO? And when would i start to consider replacing them for a/m? Besides the obvious being worn out, is it the power or the rpms that factor? I will be reving to 8000rpm ( rb25/30) and 700rwhp. for argument sake they were in good condition, should i still go a/m? tomei seems the way to go.

[DRIFTER]

can't believe this thread is still going.

[drgnball34]

someone?

[Marco-R34GTT]

Nengun sell aftermarket Tomei valve guides...

[drgnball34]

yes i know...and pretty dam cheap compared to some here in aust. But do i need them? 8000rpm and 700rwhp? My stock are fine and head has come back from engineering.....So if i decide to go a/m its the downtime waiting for delivery and the extra labour involed. Workshop said i didnt need them but just want to get others opinions

[DRIFTER]

if they're not worn i wouldn't replace them.

[drgnball34]

i spoke to a supplier and they said that tomei rb25 and rb26 use same guides..Can anyone confirm this? Also if r33 guides would be the same as r34? Im thinking i should replace just to be on the safe side. Would be good to hear from people who still used their standard guides and what power/rpm they achived

[DRIFTER]

i'm at nearly 600hp with standard replacement guides. i havn't found an rb yet that didn't at least need exhaust guides.