valve sizes ?? 66 toro 425

geckonz08 · July 24th, 2008, 04:37 PM

with all the 45 vs 39 degrees and different width lifters, I am somewhat confused .
Guess that all I really need is the head,stem diameter and length of valves in a B HEAD 66 425 TORO.My chiltons doesn`t state this and I have looked everywhere -almost!

VALVETECHNOLOGIES appears to have very good priced valves (and stainless non-chineseum)--just a matter of the correct choice
tx in advance
mike

geckonz08 · July 24th, 2008, 09:17 PM

further to this -----I may be onto the valve head dias--2.07 & 1.68--If this is correct,and I have the heads worked for these valves , should I use an adjustable valvetrain ??I sure don`t fancy the wrong length valves
mike

joe_padavano · July 25th, 2008, 10:05 AM

The valve size is unrelated to the lifter bank angle or lifter diameter. All Toro 425 motors should have 2.070/1.625 valves. If you have the 1.68 exhaust valves installed, that wouldn't be a bad thing. The two things you need to worry about are valve spring installed height and valve tip installed height. A competent machine shop will verify both of these dimensions in the course of a head rebuild. The spring installed height can be corrected with shims if necessary (since cutting the valve seats will result in a taller than spec installed height). The installed height of the valve tips can similarly be measured and corrected by machining the tips of the valves (or adding caps in the unlikely case that the valve tips are low). In any case, properly machined and assembled heads should not require an adjustable valvetrain with a stock-type hydraulic cam. More to the point, an adjustable valvetrain is frankly a bandaid for improperly assembled heads. Now, if you have an aftermarket cam with a reduced base circle or lift in excess of stock levels, then you may need the adjustability.

geckonz08 · July 25th, 2008, 01:27 PM

Quote:

Originally Posted by joe_padavano

The valve size is unrelated to the lifter bank angle or lifter diameter. All Toro 425 motors should have 2.070/1.625 valves. If you have the 1.68 exhaust valves installed, that wouldn't be a bad thing. The two things you need to worry about are valve spring installed height and valve tip installed height. A competent machine shop will verify both of these dimensions in the course of a head rebuild. The spring installed height can be corrected with shims if necessary (since cutting the valve seats will result in a taller than spec installed height). The installed height of the valve tips can similarly be measured and corrected by machining the tips of the valves (or adding caps in the unlikely case that the valve tips are low). In any case, properly machined and assembled heads should not require an adjustable valvetrain with a stock-type hydraulic cam. More to the point, an adjustable valvetrain is frankly a bandaid for improperly assembled heads. Now, if you have an aftermarket cam with a reduced base circle or lift in excess of stock levels, then you may need the adjustability.

geckonz08 · July 25th, 2008, 01:44 PM

Thanks joe . I like to be in the " forewarned is forearmed " bracket prior to the rebuild .

Nearly everything is chevy or ford because the market is so small and hence little is supplied,stocked or worked on outside the above 2 players . Finding the exception is the tricky part.Even the oldsmobile clubs are 1200 miles across the ocean in Australia.

I will be installing a very mild ,more modern profile cam whilst the engine is in pieces.Exactly what I am unsure till I have all the info together.
your help is appreciated
mike

July 24th, 2008, 04:37 PM	#1 (permalink)
geckonz08 Registered User Join Date: Apr 2008 Location: new zealand Posts: 218	valve sizes ?? 66 toro 425 with all the 45 vs 39 degrees and different width lifters, I am somewhat confused . Guess that all I really need is the head,stem diameter and length of valves in a B HEAD 66 425 TORO.My chiltons doesn`t state this and I have looked everywhere -almost! VALVETECHNOLOGIES appears to have very good priced valves (and stainless non-chineseum)--just a matter of the correct choice tx in advance mike

July 25th, 2008, 10:05 AM	#3 (permalink)
joe_padavano Super Moderator Join Date: Mar 2007 Location: Northern VA Posts: 4,396	The valve size is unrelated to the lifter bank angle or lifter diameter. All Toro 425 motors should have 2.070/1.625 valves. If you have the 1.68 exhaust valves installed, that wouldn't be a bad thing. The two things you need to worry about are valve spring installed height and valve tip installed height. A competent machine shop will verify both of these dimensions in the course of a head rebuild. The spring installed height can be corrected with shims if necessary (since cutting the valve seats will result in a taller than spec installed height). The installed height of the valve tips can similarly be measured and corrected by machining the tips of the valves (or adding caps in the unlikely case that the valve tips are low). In any case, properly machined and assembled heads should not require an adjustable valvetrain with a stock-type hydraulic cam. More to the point, an adjustable valvetrain is frankly a bandaid for improperly assembled heads. Now, if you have an aftermarket cam with a reduced base circle or lift in excess of stock levels, then you may need the adjustability. __________________ Joe Padavano 64 Jetstar 88 Conv 66 442 L-69 Conv 68 W-30 69 H/O 69 442 70 W-30 72 442 84 Custom Cruiser 86 Caprice wagon (w/307 Olds)

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July 24th, 2008, 09:17 PM	#2 (permalink)
geckonz08 Registered User Join Date: Apr 2008 Location: new zealand Posts: 218	further to this -----I may be onto the valve head dias--2.07 & 1.68--If this is correct,and I have the heads worked for these valves , should I use an adjustable valvetrain ??I sure don`t fancy the wrong length valves mike

July 25th, 2008, 01:44 PM	#5 (permalink)
geckonz08 Registered User Join Date: Apr 2008 Location: new zealand Posts: 218	Thanks joe . I like to be in the " forewarned is forearmed " bracket prior to the rebuild . Nearly everything is chevy or ford because the market is so small and hence little is supplied,stocked or worked on outside the above 2 players . Finding the exception is the tricky part.Even the oldsmobile clubs are 1200 miles across the ocean in Australia. I will be installing a very mild ,more modern profile cam whilst the engine is in pieces.Exactly what I am unsure till I have all the info together. your help is appreciated mike