will loose lash tame oversize cam?

[4banger]

If the cam in a race engine is considered to be too big, can more lash calm it down as far as making it work as a smaller cam? Its a solid flat tappet with .10 lash hot. Will more lash cause a problem? How much? Not talking about advancing/retarding the cam, just generally speaking about changes in lash... What about a cam makes you think it's too big or small?

[Pontiac_Puller]

You are correct, a looser lash will decrease duration. However, there is no way to tell how much lash equals how much duration, due to differences in ramp angles from one cam to another. The only way to tell is with a degree wheel. Then there's the obvious issue with excessive lash causing increased wear on all contact points. It might take more lash than you think to make any noticeable difference, and I wouldn't want to use much more than the cam manufacturers spec. They're often on the loose side as it is.

[chevyfreak]

You are correct, a looser lash will decrease duration. However, there is no way to tell how much lash equals how much duration, due to differences in ramp angles from one cam to another. The only way to tell is with a degree wheel. Then there's the obvious issue with excessive lash causing increased wear on all contact points. It might take more lash than you think to make any noticeable difference, and I wouldn't want to use much more than the cam manufacturers spec. They're often on the loose side as it is.

I've done the opposite, have an ford essex v6, english made engine, lash at 0.33int and 0.55ex hot (mm listed), I'm running it at 0.20 int and 0.25ex, engine responds better and runs a lot quieter, its still a stock cam and runs good, as for going bigger lash it will tame down a bit but like pontiac puller said by how much is difficult to say, and more noise wil come in to play, depending on how much lash u are adding maybe something can go wrong, for us 010 sounds small but inside an engine its a different story, best would be contact cam manufacturer,
Chevyfreak,

[cjperformance]

If the cam in a race engine is considered to be too big, can more lash calm it down as far as making it work as a smaller cam? Its a solid flat tappet with .10 lash hot. Will more lash cause a problem? How much? Not talking about advancing/retarding the cam, just generally speaking about changes in lash... What about a cam makes you think it's too big or small?

Basically yes, but you cant go looser than the lash ramps allow or you will run into valve train problems. Can you fit lower ratio rockers? What engine?

[twl]

If you do some loosening of the lash, and the engine makes more power, or responds better, then you have too much cam.
People sometimes do this check with the lash to see if their cam is right. As previously stated, you can only go to a certain extent with this loosening of the lash.

However, if you have WAY too much cam, you may not be able to loosen the lash enough to find out how much of a "too much" cam you have. Sometimes people put a real lot more cam than they need in an engine.

I agree that changing to a lower ratio rocker can be a good fix in some cases.

[PackardV8]

Can you fit lower ratio rockers?

I agree that changing to a lower ratio rocker can be a good fix in some cases.

Your results may vary, but in my limited experience, a lower ratio rocker on a too-long duration cam just lowers mid-range and top end horsepower, but still keeps the same soggy low end.

A lower ratio rocker lessens the area under the curve, but doesn't shorten the duration or the overlap. It does slightly lessen the area of the overlap

[cjperformance]

Can you fit lower ratio rockers?

I agree that changing to a lower ratio rocker can be a good fix in some cases.

Your results may vary, but in my limited experience, a lower ratio rocker on a too-long duration cam just lowers mid-range and top end horsepower, but still keeps the same soggy low end.

A lower ratio rocker lessens the area under the curve, but doesn't shorten the duration or the overlap. It does slightly lessen the area of the overlap

Yep its only a crutch.And at the end of the day is probably cheaper and definetly more effective to just change the cam

[289nate]

Can you fit lower ratio rockers?

I agree that changing to a lower ratio rocker can be a good fix in some cases.

Your results may vary, but in my limited experience, a lower ratio rocker on a too-long duration cam just lowers mid-range and top end horsepower, but still keeps the same soggy low end.

A lower ratio rocker lessens the area under the curve, but doesn't shorten the duration or the overlap. It does slightly lessen the area of the overlap

Yep its only a crutch.And at the end of the day is probably cheaper and definetly more effective to just change the cam

I don't know that I'd even call it a crutch. Slower rate of lift on the intake valve with the same excessive seat duration sounds like a step backwards. I doubt it lowers overlap enough to make any meaningful difference.

[bigjoe1]

I have seen where just setting the intake lash 005 looser made a big difference in a drag race setup. I have also seen a 30 HP gain where the engine cannot rev high enough in a jet boat situation.( 30 more at 6000 RPM ) because the cam wanted to peak out at 6600 RPM )


JOE SHERMAN RACING

[JohnnyB]

If the cam in a race engine is considered to be too big, can more lash calm it down as far as making it work as a smaller cam? Its a solid flat tappet with .10 lash hot. Will more lash cause a problem? How much? Not talking about advancing/retarding the cam, just generally speaking about changes in lash... What about a cam makes you think it's too big or small?

It may "Tame it" a little at first. However "too loose" may tame it a whole bunch. By BEATING the entire valve train into submission...........

Do you really want to roll the dice by opening the lash up more than the cam grinder spec'ed ???? For a very small gain?

Is this your motor, a customers engine, or a guy down the street that you really don't care for?