Hi-po camshaft - Valve bounce or clearance?

[Yspen]

Some of you may know by other threads that I have rebuilt a 2F here in Africa . https://forum.ih8mud.com/60-series-wagons/399712-another-2f-rebuild.html

Well the car was taken for its first proper run today .

It pulls very strong and I get a boost of power at about 2400rpm that is awesome .
BUT ... the tappet noise at 2700 - 3000rpm ( not gone higher yet ) is so noisy it is unbearable .

Option one : close the valve clearance ( valve lash ) a bit ( but I suppose that may change the specs of the camshaft timing ? )

option two : is it perhaps "valve bounce" .
I decided against fitting new coils due to a thread where Mark W said :

I have... and continue to... run cams with .442 lift and stock springs in over a dozen engines. And I have sold the same cams to at least as many others who have done the same.

Mark W again :

Take the shims out and let the valve springs have all of their height back. I have been running these cams for years and pushing engines up to and beyond the capabilities of the lower end. I run stock, unshimmed valve springs and have NEVER encountered valve float. The springs will be close to their limits, but they will not stack or bind.

I suppose that is due to the potential valve bind problem but I may be experiencing valve bounce problems .

(How urgent do I need to fix this issue ?)

 

[Yspen]

Please also advise what springs I need to fit if that is the issue ( I have seen threads where SBC springs are advised ) . Not too sure if I will get that here in SA - may need to import )

 

[Slowerthanu]

You need to pull the springs and check maximum closed height for binding.

Honestly, I do not know the formula for determining how stiff of a spring you need to eliminate float.

You could try stock, new springs and see if your are simply worn out. Every manufacturer recommends new springs, lifters and pushrods on a cam replacement.

 

[Yspen]

Found some info here : https://forum.ih8mud.com/60-series-wagons/175021-2f-valve-spring-issues-2.html

I still wonder where I am going to get new springs - where to order ( part no )

 

[fliphkd778]

You can just run sbc valve springs. They drop right in. I used them for the delta 262 grind. Get them from northern auto parts. Mine are "z28" springs, and feature a second harmonic dampening spring I assume to prevent what you are experiencing.

I've tried to get springs off with the head on, and the stock coil wraps were too close to get the compressor on it. However, if you go with a sbc spring, the distance between wraps would be larger and allow for the tool.

 

[lehiguy]

I got coil bind with .440 lift. The stock springs are way too soft for serious consideration with any cam other than stock. Removing the shims will increase the likelyhood of valve float which sucks just a much as coil bind. Get different springs.

 

[Yspen]

Hi Flip - I need more info please ( after a while I figured that z28 is a camaro - remember we do not have these cars here ) . NAP has about 8 valve springs listed for the z28 . Can you help me with a part no ? please

EDIT : is it this part ? : http://www.northernautoparts.com/ProductModelDetail.cfm?InventoryId=37873

(It seems way cheaper than the springs listed for the 2F : http://www.northernautoparts.com/ProductModelDetail.cfm?InventoryId=37901 )

 

[fliphkd778]

I'm not even sure what z28 springs are myself, but I think they are the high lift version of the 350 valve springs. Don't get them, I feel the seat pressure is too high even though my machinist assured me my cam would be fine.
These look just like the ones in mine. Pioneer stock replacement.
Northern Auto Parts: - Pioneer Stock Valve Springs

 

[lehiguy]

You should really talk to an experienced head rebuilder. All the available refference material plus experience should give you a good idea where you are right now (seated pressure, opened pressure, coil bind height, installed height, O.D., I.D., etc.) and what would be the next step. I have learned the hard way that performance cams and stock springs are a recipe for disaster in almost every case. Just because it runs today, doesn't mean that in a year your valves and seats won't be burned and your rockers and other hardware damaged from valve float or coil bind.

 

[Yspen]

Found some interesting info :

Crow cams list a set of valve springs for a 2F with 0.420" cam : http://www.crowcams.com.au/media/catalogues/42.0 Toyota.pdf

The also use the same valve spring in SBC 350 ( see 4828 on the list ):
http://www.crowcams.com.au/media/catalogues/46.0 SPRING Application all.pdf

If you use those specs then the following should work:
1. Comp cams 980
Comp Cams Performance Valve Springs
2. Howard valve springs 98214
Howards Cams Performance Street/Strip Valve Springs
3. Pioneer springs ( not sure as specs not listed )
Northern Auto Parts: - Pioneer Stock Valve Springs

 

[fliphkd778]

The pioneer rv880x's have a seat pressure of around 85lbs.

 

[CardinalFJ60]

TLCA tech editor?

if you are a TLCA member, this would be a great question for the Tech Editor. Robbie knows his stuff, especially about rebuilding 2F's (I should know. ) if it gets published in "trails" this could really help out alot of Cruiser-folk.

sorry for quasi-hijack with no advice.

 

[lehiguy]

Found some interesting info :

Crow cams list a set of valve springs for a 2F with 0.420" cam : http://www.crowcams.com.au/media/catalogues/42.0 Toyota.pdf

The also use the same valve spring in SBC 350 ( see 4828 on the list ):
http://www.crowcams.com.au/media/catalogues/46.0 SPRING Application all.pdf

If you use those specs then the following should work:
1. Comp cams 980
Comp Cams Performance Valve Springs
2. Howard valve springs 98214
Howards Cams Performance Street/Strip Valve Springs
3. Pioneer springs ( not sure as specs not listed )
Northern Auto Parts: - Pioneer Stock Valve Springs

That is exactly the type of information needed. Well done Yspen.

 

[fliphkd778]

What are you looking for in terms of seat pressure?

I'm learning a bit more about my springs. Apparently there are two stock 350 springs, a "350" spring and an "lt1" spring. The 350 spring is part number vs677 from federal mogul, and has a seat pressure of 80 lbs, while the lt1 spring(VS739R) I may be running is 105lbs. I want the lightest seat pressure for longevity. You can tell the two apart by one having a wire dia. of 1.77", the other are .192".

We need to get Dave-T on here, he has some sbc springs in his head...

 

[Yspen]

I contacted Crowcams and they have sent me the following message:

I do not have any of the 4828 springs at the moment.
I have a spring with a similar pressure , part number is 4830-12 these have a damper in them.

The cost for a set of 12 springs is $ 72.00 ( Aus )


The SBC springs have too much open pressure and not enough seat pressure. The low seat pressure is one of the reasons these engines burn valves out.

I find the last comment strange as they use the 4828 in the SBC.
So IMO SBC springs with seat pressure of 85 at 1,79" will work fine in the 2F.
These springs are very costly - to ship them to me incl will cost me US $ 102 .
I am sure we can find SBC springs that will work well at half the cost .

 

[fliphkd778]

I'm thinking the vs677's. In my rebuild thread Jim C. mentioned his sbc springs had a seat pressure of 60-70 lbs. If I remember right.

Now compare to stock specs from the FSM:
Free length: 2.028"
Installed length: 1.693"
Installed load: 71.6 lbs, limit = 59.5 lbs.
Rate at upper installed load = 71.6/(2.023-1.693) = 213.7 lbs/in
VS677 Specs:
Free length: 2.03"
Installed length: 1.7"
Installed load: 80 lbs
Coil Bind @ : 1.15"
Rate: 267 lbs/in
On coil bind, Jim C. posted an equation to check for coil bind. ::
------------------------------------------------------------------------
1. compress springs to stacked height, measure.
2. measure installed height of spring.

A good rule of thumb is to only run a spring to within .060" of its stacked height.

math time:
installed height - .426" => stack height + .060"

Or crush the spring to it's stacked height, measure, and make sure that when the engine is assembled the compressed height is .060 greater.
----------------------------------------------------------------------------
I don't know the stacked height of a stock spring, but a vs677 will bind at 1.15".

Therefore the left side yields:
1.7"-.426" = 1.274
The right side:
1.15"+.06" = 1.21"
So the statement is true.

 

[Yspen]

Thanks Flip
The VS677 will be perfect - I'm ordering today from NAP - I have a friend flying out next month , he can bring it to me .

 

[fliphkd778]

Good deal, how are you planning on removing the current valves?

 

[Yspen]

My mechanic has a tool that allows the valve springs to be replaced without removing the head .

 

[fliphkd778]

How will you prevent the valves from dropping in the head? Will it work on the last valve under the cowl?