vettemad

Hi Guys, I pulled a head to get at a sticky valve on my 1970 toro and was thinking when I pulled that valve...where's the valve guide? I don't see one...Don't these 455 toros have valve guides? or am I blind?...thanks now!...

Olds64

The valve guide is inserted into the head with an interference fit. The valve stem travels up and down in the valve guide.

vettemad

I understand that, and they're generally bronze and bronze colored as a result....I just don't see one there...

Oldsmaniac

Olds did not use replace-able guides for the most part. The head is knurled which is sorta like a thread to control oil. when a valve job is done guides can be installed or the guide re-knurled.

Olds64

I'm not sure if the original valve guides were bronze or iron/steel.

Talking about replaceable valve guides is sort of odd to me. I rebuilt the heads on my dads 455 and replaced all the valve guides by drilling out the old ones and pressing in and cutting new ones.

vettemad

Oldsmaniac's reply sounds right for my application , things can change year to year to model to model with all manufacturers, I'm no virgin and have seen many heads naked and guides are visible...normally, that's why I posted...thanks, cliff

joe_padavano

The stock heads had neither a press-in valve guide nor knurling. The valves simply rode on the cast iron surface. Oil leaking past the valve seals and lead in the gasoline combined to provide lubrication. If the "guide" (actually, just the bored hole) is excessively worn or damaged, you can either knurl the I.D. of the hole and ream to size, or you can bore and install aftermarket bronze guides.

Oldsmaniac

Seems odd and I am certain the heads I have looked at had a spiral design in the valve guides. I am talkin 66 Bb heads which were ever machined before as far as I could tell....

Oldsmaniac

Seems odd and I am certain the heads I have looked at had a spiral design in the valve guides. I am talkin 66 Bb heads which were never machined before as far as I could tell....

vettemad

Thats another reason I posted...after seeing guides listed for 455 olds's at parts stores I had to rethink this and then posted... mine, I would describe as a little sloppy, normal for a car showing 84k original miles...I will clean it up and put it back together...the carbon can take it's rightful place, taking up the slack and forget it...the reason It was stuck is the 30 years this car sat....thanks again guys!....cliff

Olds64

I agree Oldsmaniac. I've seen numerous Olds heads disassembled with knurling in the valve guides. I thought this was standard practice on all Olds heads from the factory. Then again, it could have been that all of the heads I saw were already serviced at the dealer years ago. Perhaps there was a service bulletin to knurl the valve guides on all Olds engines at a certain mileage.

Warhead

That is not technically a knurl, but was from the tooling to size the guides.
Knurling will typically leave a spiral 2-3 times tighter, and leave less metal supporting the valve stem. All assembly line heads had the loose spiral.
ALL factory guides were sized from the cast iron material that comprised the original head casting. Any replaceable guide will require you to drill the head.

Now, how did you stick this valve???
Jim

Oldsmaniac

Thanks for clearing things up on the spiral, and also according to the factory shop manual the spiral was intentional and not just coincidental to provide lubrication and control oil as well. A worn guide should be reamed and then valves with thicker stems used. It states that should the spiral be completely removed it could cause a lack of lubrication to the valve stem..

Olds64

That is good info to know.