My valve problem continues! Any ideas where I could get valves made for my Toyota? I'm having trouble finding someone who can!
Need 1s that are more heat resistant! Mine are expanding causing more cam clearance and it sounds 'tappety' when hot! :confused:

My valve problem continues! Any ideas where I could get valves made for my Toyota? I'm having trouble finding someone who can!
Need 1s that are more heat resistant! Mine are expanding causing more cam clearance and it sounds 'tappety' when hot! :confused:
Try:

Supertec: North Carolina, America http://www.supertechperformance.com/

My valve problem continues! Any ideas where I could get valves made for my Toyota? I'm having trouble finding someone who can!
Need 1s that are more heat resistant! Mine are expanding causing more cam clearance and it sounds 'tappety' when hot! :confused:

can you tell us how you have arrived at this conclusion?
usually if the valves expand this will reduce the tappet clearance.
standard toyota valves are very very good in this respect, i dont
think the atlantic spec ones will be any better(apart from being bigger)

Most likely detonating causing a pinking sound. Is it a hi Compression Rally engine on Carbs

It's 12:1 compression Toyota engine on Jenvey throttle bodies.
The head of the valve(in cylinder) is expanding so it doesnt close(as much) on the valve seat so there is more clearence on top at tappet(bucket in this case as they are solid cams, clearence is adjusted with shims)

It's 12:1 compression Toyota engine on Jenvey throttle bodies.
The head of the valve(in cylinder) is expanding so it doesnt close(as much) on the valve seat so there is more clearence on top at tappet(bucket in this case as they are solid cams, clearence is adjusted with shims)
i think your barking up the wrong tree there. let us assume the problem is with the exhaust valve(it gets much hotter), the expansion rate would have to be massive to make any significant difference to the tappet clearance. dont forget, if the head is expanding widthways the stem will be expanding lengthwise thus cancelling eachother out.but i think the changes are relatively insignificant
do you use the standard shim on top of the bucket or a shim underneath?
if you use a shim on top a situation can arise with certain cam profiles where the initial contact between the cam and the bucket is right at the outside of the diameter of the bucket (shim in this case). because of the shape of the top of the bucket (its got a slight recess/groove around the outside,underneath the shim),the shim can tip/rock for the first few degrees of cam movement.it makes an awful racket when the engine is hot. difficult to explain but simple when you see it.
only cure for that one is steel buckets with shim under.do you what the profiles are?

i think your barking up the wrong tree there. let us assume the problem is with the exhaust valve(it gets much hotter), the expansion rate would have to be massive to make any significant difference to the tappet clearance. dont forget, if the head is expanding widthways the stem will be expanding lengthwise thus cancelling eachother out.but i think the changes are relatively insignificant
do you use the standard shim on top of the bucket or a shim underneath?
if you use a shim on top a situation can arise with certain cam profiles where the initial contact between the cam and the bucket is right at the outside of the diameter of the bucket (shim in this case). because of the shape of the top of the bucket (its got a slight recess/groove around the outside,underneath the shim),the shim can tip/rock for the first few degrees of cam movement.it makes an awful racket when the engine is hot. difficult to explain but simple when you see it.
only cure for that one is steel buckets with shim under.do you what the profiles are?
mmmmmmmm

I e-mailed Super Tech Performance and they sent this back.

In order for us to manufacture valves, we must do a run of 50 per size. The
cost of this would be approximately $28 per valve.

I know exactly what you're saying Whatbloodynamecaniuse with the shim tip/rocking for the first few degrees of cam movement but to prove what I'm saying is happening,when I remove the rocer cover quickly after engine gets hot,the valve clearence has doubled! This has shocked alot of engine guys over the years! Ya can hear the tappety noise worse through the intercom than when standing beside the engine! The shims are between the top of the valve(stem) and the bucket. i.e. underneath the bucket! This problem doesn't effect engine performance though

Your just too fussy! Drive on!

New stainless valves arrived aft long time, fitted them and prob. is worse, even more noise :-( ! I'm being told the aluminium head is very big, not designed for compression as high as I've got and is expandin' alot causin' cams to move up and away from valve buckets?????????????????????
Also I'm bein' told the stem of new stainless valves are more heat resistant, stem is not expanding in lenght as much causing valve clearence to increase! Both opinions came from big Irish rally engine builders! Valve clearence set to 10 thou(recommended)! It expands to 20!!!! Gonna try 5 thou(risky cause of high of compression pistons fitted)New shims have to be manufactured again for this, time and money!

can you tell me where you got the valves made as I am looking for some for my Fathers veteran car?

Hi rwd only. Not trying to be smart but are you an engine build by trade? If not why don't you save yourself time, trouble and money and give it to a reputable engine builder to sort it for once and for all?????

If you can't get a valve that will operate correctly another option might be
to try lower the combustion chamber temperatures i.e. piston oil squirters,
ceramic coating for the valve faces, adjusting engine mapping.

Have you seen inside the compression chamber since you've had this problem,
are you happy there's no damage being done?

Supertech's valves are decent but steer clear of their valve gear (valve
springs, retainers).

I'm not doing the work to this engine Mr.M, wouldn't dream of it! I brought it to reputable engine builders, 3 of them and opinions they gave are mentioned above! It's being returned to 1 of them for the valves to be set @ 5thou and we'l see how that goes! I'll keep ye up to date!
Never heard of piston squirters before but def. gonna look into it! Engine is dry sumped!
Engine has been remapped to different settings a few times and moved from MBE to Omex! I did see the compression chambers and no damage being done!

Richard macer - rmsport was the man for twin cam stuff once upon a time - I probably have a number for him somewhere if interested

I have used Ferrea valves and find them very good, you can look up sizes on their site. Co-Ord sport in the UK are suppliers

Put the valve clearance to nearly zero, if the gap is getting bigger when it's hot( which is very weird) then in theory you don't need clearance as tappet clearance is only to allow for a reduction in clearance as the engine heats up (like every othe engine in the world)