valve guide cutting

raj4851

Member
Hey Grumpy, I began to upgrade my 355 and when I took a couple of valve springs off to check piston to valve clearance I discovered my valve guides cracked. These heads were ported, large springs, 7/16" studs with guide plates. No, I didn't check the retainer to guide clearance before hand. That's what I get for assuming. I was running a 280H Comp cam with 1.6 rockers. I think that made valve lift about .520. As I said, shame on me. The guides are cracked down to the bigger part at the bottom of the guide. Can I cut the bigger portion at the bottom of the guides for seals and be okay? Is that enough guide? Thanks in advance, Rod
 
clear,pictures with a good bit of detail. posted here ,would help a good deal of help?

but from the limited description I think youll need a machine shop to replace the valve guides

10-13.jpg
images

a video that shows sloppy or careless component prep work on a set of chevy performance heads
,keep in mind on any heads you get from any vendor or back from any machine shop you need to carefully inspect them for machine damage, machining chips and lack of cleaning.






read this link
http://www.engineprofessional.com/articles/EPQ215_18-38.pdf
while the equipment required can be modest (A DRILL PRESS AND MACHINIST VISE and TOOLING) or rather expensive (A MILL AND MACHINIST VISE and TOOLING) the jobs not very difficult

yes you need to as stated, many times on this and other websites, check all your valve train clearances carefully, but in this case theres almost certainly no cause to be concerned here as the minor difference in spring load rates and installed heights is probably well within the intended valve train and cams design limitations, keep in mind the max cam lift is .520
drawsdf.jpg


those heads (keep in mind that price is for a single (1) cylinder head)
https://www.summitracing.com/parts/tfs-30410001/overview/

OBVIOUSLY YOULL WANT THE CORRECT VALVE SPRINGS

http://www.competitionproducts.com/1500-1585-OD-Valve-Springs/products/2631/1/0

https://www.summitracing.com/search/part-type/valve-springs

https://www.iskycams.com/cart/valve-springs-c-99.html

http://www.cranecams.com/userfiles/file/334-343.pdf

https://www.racingsprings.com/Valve-Spring/Store/13

http://www.lunatipower.com/Category.aspx?id=23

http://www.pspring.com/products/engine-valve-springs/

http://www.competitionproducts.com/Valve-Springs/departments/49/

http://psisprings.com/products/

http://www.compcams.com/Products/CC-'Valve Springs By Usage'-0.aspx

http://www.racingsprings.com/Beehive-Valve-Springs

https://www.supertechperformance.com/valve-springs-p109

http://www.cvproducts.com/index.php/psi-springs/

you might also want to keep in mind theres a great deal more to setting up a valve train than slapping some springs and retainers and keepers on the valve
s.
read thru the links and sub links as theres a great deal of useful info, that youll want to know.
btw just a bit more info, there are valve spring retainers, valve spring seats, shims, valve retainer keepers etc. that can be used that have different sizes or depths that allow you to change the installed height, or relation of the spring to the valve stem , it compressed height, or the valve springs location in relationship to the stems locking groove
keep in mind shims under the valve springs can be used to raise the spring or shorten the valves installed height, valve locks and retainers can be purchased with non-O.E.M dimensions to adjust the valves installed height or spring load rates
you use either or both depending on the application
a .050 PLUS valve lock moves the retainer .050 higher on the valve stem with no other changes, a plus .050 retainer would move the retainer .050 higher with stock valve locks or an additional .050 if matched to .050 plus locks
if you used a plus .o50 retainer with a set of minus .o50 valve locks the retainer would remain at the stock height on the valve stem

http://www.jegs.com/p/Crane/746983/10002/-1

http://www.jegs.com/p/Moroso/764349/10002/-1

http://www.jegs.com/p/Manley/940089/10002/-1

http://www.jegs.com/p/Comp+Cams/757964/10002/-1
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660-42379-16.jpg

valvespringseats.png

valsp1.jpg

valsp2.jpg

valsp3.jpg

valsp4.jpg

prctool.png

youll have to correctly measure the clearance on your heads with the valve springs and cam specs you selected too use to know if you have the correct valve spring installed height and clearances, failure to accurately check frequently results in very expensive repairs and to what new guys frequently blame on the cam when it was a installers ignorance that was the true cause.

https://www.summitracing.com/parts/pro-66902/overview/

https://www.summitracing.com/parts/sum-900032/overview/

https://www.summitracing.com/parts/rsc-pac-t902/overview/

pic16vc.jpg

pic19vc.jpg


springmicv.jpg

vsmt7a.jpg

pic18vc.jpg

pic20vc.jpg


vspr1.jpg

valve springs must be installed at a specific semi compressed and listed installed height,
to provide the listed load rates and clearances,
example

crane110921.jpg

the cam you select will generally come with a suggested listed valve spring load rate and installed height,
(NOTICE THE SUGGESTED INSTALLED HEIGHT WITH THIS CAM IS 1.800"
and the loads are listed)

you must maintain minimum coil bind and retainer to valve seal clearance and proper push-rod and rocker geometry
the distance between the lower edge of the valve spring retainer and the cylinder head is adjustable to achieve the desired valve spring height through the use of valve spring seat cups and shims placed under the valve spring which can be purchased to lock into a stock height, or plus or minus about .050, and valve locks that cam move the retainer (stock or aftermarket) an additional .050 either tighter or longer allowing the valve spring to expand taller, shims can be placed under the valve seat hardened cups that are almost always mandatory on aluminum head but may be optional on iron heads,(O.E.M. cast iron and lower valve spring load rates)

ValveSpringDetail.gif


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valvespringinstalled.gif


springshima.jpg

prctool.png


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bbcspring2.gif

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edvalvs.jpg

valvespringseats.png

Installedsp.jpg

valvespringseatsx.png

max lift is installed height minus .060 minus coil bind
drawsdf.jpg

related info you really need to read
http://garage.grumpysperformance.co...ring-installation-questions.12833/#post-66460

http://garage.grumpysperformance.co...-loads-and-installed-height.10709/#post-46658

http://garage.grumpysperformance.co...ve-spring-iinstalled-height.12791/#post-66038

http://garage.grumpysperformance.co...train-clearances-and-problems.528/#post-57678

http://garage.grumpysperformance.com/index.php?threads/valve-springs.9613/#post-50556

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/

push rod to short
WIDE SWEEP ON VALVE TIP FROM ROCKER ADDS ADDITIONAL,
SIDE LOAD WEAR
long.jpg

push rod to long
correct.jpg


push rod length correct
AS CLOSE TO CENTER AS POSIABLE BUT BEING CENTERED IS LESS IMPORTANT THAN MINIMAL SWEEP ON THE VALVE TIP< INDICATING MINIMAL SIDE LOADING

http://garage.grumpysperformance.co...-pushrods-and-check-info-you-might-need.5931/
http://www.summitracing.com/search/...d-length-checkers?autoview=SKU&ibanner=SREPD5
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs
a few simple tools will tell you if clearances are ok

12cal.jpg


Feeler-Gauge.jpg


READ THESE LINKS CAREFULLY

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/

http://garage.grumpysperformance.com/index.php?threads/checking-piston-to-valve-clearances.399/

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/
http://garage.grumpysperformance.co...w-cam-now-engines-burning-a-bit-of-oil.14569/

http://garage.grumpysperformance.com/index.php?threads/milling-machine-related.4231/#post-33023

viewtopic.php?f=52&t=5306&hilit=valve+seals

http://www.cylinderheadsupply.com/valve-guide-tools-guide-top-cutters.html

http://garage.grumpysperformance.com/index.php?threads/oily-crud-on-intake-valves.12083/#post-57903

https://www.summitracing.com/search/part-type/valve-guide-cutting-tools

https://goodson.com/

have you ever asked yourself why the chevy valve seal sets look like tis picture or why the intake seals look like the blue spring loaded plastic cylinders while the exhaust uses a simply squared off O-ring?
the intake port runs on rapidly changing negative pressure or SUCTION, (no its really not, its just significantly lower than the outside air pressure caused by the open valve over a rapidly descending piston, in the bore, without a valve OIL SEAL an excessive amount of oil would be constantly flowing through the valve stem/valve guide clearances, thus the need to limit the potential oil flow rate with a valve seal, but the EXHAUST port operates on both a positive and intermittent negative pressure wave valve cycle and at much higher temperatures, so the valve stem to valve guide is operating at an intermittent pressure wave that's far less likely to over lubricate, from oil in the upper cylinder head and oil flow over the valve springs etc, thus the simple O-ring seal is frequently a large enough restriction to oil flow to allow the exhaust valve to operate without excessive oil flow rates.
yes some valve seal setts use the intake style valve seals on both the intake and exhaust valves, but generally they will be a different color and be marked in some way as exhaust/ intake seals as the different type of valves (INTAKE VS EXHAUST) operated best with different oil flow clearances
fel-ss72527_w.jpg


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https://www.engineprofessional.com/articles/EPQ215_18-38.pdf

valve guide cutting

Hey Grumpy, I began to upgrade my 355 and when I took a couple of valve springs off to check piston to valve clearance I discovered my valve guides cracked. These heads were ported, large springs, 7/16" studs with guide plates. No, I didn't check the retainer to guide clearance before hand...
garage.grumpysperformance.com
 
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