How do you economically stock different size valve tappets?

[Wallythacker]

If you rode a Kawi superbike in the 70/80's like I did the 4 cyl. inline air cooled monsters needed the valve lash adjusted at least yearly and if you rode as I did with the tach on the redline all the time 2x yearly adjustment was called for.

Plan to spend 1/2 a day with your assortment of 200+ shims of varying size. IIRC there were shims with a .005mm difference. It wasn't a simple measure the gap with feelers a select the matching shim. It was figure out what was required for ALL the valves, then build up what was required,

[sunbeam]

If you rode a Kawi superbike in the 70/80's like I did the 4 cyl. inline air cooled monsters needed the valve lash adjusted at least yearly and if you rode as I did with the tach on the redline all the time 2x yearly adjustment was called for.

Plan to spend 1/2 a day with your assortment of 200+ shims of varying size. IIRC there were shims with a .005mm difference. It wasn't a simple measure the gap with feelers a select the matching shim. It was figure out what was required for ALL the valves, then build up what was required,

Have new camshafts so I expect the adjustment to be needed.

I was thinking maybe the local dealership sells me a bunch then returning the unused caps?

[Wallythacker]

speak with them before you order the shims. something might be able to work out

[foama]

sunbeam, just curious, why do you need new camshafts? You would be the first in this forum.

[sunbeam]

sunbeam, just curious, why do you need new camshafts? You would be the first in this forum.

Not the first:

https://mirageforum.com/forum/showth...-Cams-Thailamd


Dont "need" new camshafts but I put this in the "cheap thrills" category.

Based on the reported specs, I consider this more of a fuel economy mod.

Waiting for the warranty to expire before install.

[Eggman]

Not the first:

https://mirageforum.com/forum/showth...-Cams-Thailamd


Dont "need" new camshafts but I put this in the "cheap thrills" category.

Based on the reported specs, I consider this more of a fuel economy mod.

Waiting for the warranty to expire before install.

Wouldn't changing the valve operation require remapping the fuel delivery?

[7milesout]

Wouldn't changing the valve operation require remapping the fuel delivery?

Wouldn't flowing more air *decrease* mpg? I wouldn't think this to be a fuel economy mod. More like a power mod.

Eggman - Tis a good question, to be sure. But I wonder, if the valves open more, and more air enters the cylinder, and the O2 sensor sees lean ... wouldn't then the computer adjust to add fuel to achieve its target AFR? I just wonder that ... I don't know the answer. But I suspect that the computer would *actually add more fuel in its attempt to achieve its programmed AFR.

I wonder if it could actually achieve its target AFR. Seems like that much more air is not something that would overcome the potential of the fuel injectors. But I don't know that. In any event, even if the computer adds more fuel, up to its limit and still doesn't quite get to its target AFR, I suspect the result would be a) more power (due to more air and more fuel), and b) check engine light illumination for AFR out of spec (whatever that error might read) if it cannot achieve its programmed AFR.

I'm hoping to hear more about these cams. As they are very interesting to me.

Heck ... while I'm doing my exhaust experimenting ... maybe I should consider installing an AFR gauge. Although, maybe I can read AFR from the OBD-II port and an app...

[Eggman]

Wouldn't flowing more air *decrease* mpg? I wouldn't think this to be a fuel economy mod. More like a power mod.

Eggman - Tis a good question, to be sure. But I wonder, if the valves open more, and more air enters the cylinder, and the O2 sensor sees lean ... wouldn't then the computer adjust to add fuel to achieve its target AFR? I just wonder that ... I don't know the answer. But I suspect that the computer would *actually add more fuel in its attempt to achieve its programmed AFR.

I wonder if it could actually achieve its target AFR. Seems like that much more air is not something that would overcome the potential of the fuel injectors. But I don't know that. In any event, even if the computer adds more fuel, up to its limit and still doesn't quite get to its target AFR, I suspect the result would be a) more power (due to more air and more fuel), and b) check engine light illumination for AFR out of spec (whatever that error might read) if it cannot achieve its programmed AFR.

I'm hoping to hear more about these cams. As they are very interesting to me.

Heck ... while I'm doing my exhaust experimenting ... maybe I should consider installing an AFR gauge. Although, maybe I can read AFR from the OBD-II port and an app...

I really don't know and can't speculate too much. Somewhere, probably here on this forum, I read that the fuel injection as part of engine management is programmed from the factory for certain operating parameters. A change any one part of the air/fuel equation would require reprogramming. Similarly, some changes will not see their full potential unless other similar changes are implemented. A change in the mechanical valve timing won't really make its full impact unless the air intake is modified to allow more airflow - this can include the throttle body, the snorkel, the intake manifold - whatever. Same goes with the exhaust - changes to the exhaust won't have their full potential unless the air intake is addressed and the fuel delivery as well.



I get the idea that people like to fiddle with their toys & make modifications. A lot of money can be spent on a car. For what? It reminds me of a conversation I had with a SCCA driver years ago. He said every weekend you're driving to a race somewhere, often taking time off work if the race is far away. Spend the weekend tweaking & beating up on whatever you're driving. The rest of the week is spent underneath the car throwing money at it - oil changes, fuel, brakes, tires, and whatever broke over the weekend. His summary went like this:

"Want to make a small fortune in racing? Start with a large fortune."

Unless the driver is talented enough to climb the ranks winning races & getting sponsors, racing becomes an expensive hobby.

I know we're not exactly talking about racing, but making modifications like this always reminds me of how much money can be spent on cars and that SCCA driver's summary about his hobby.

The Mirage works great as it is for what it is - basic, economical, reliable transportation. Will the modification further improve on the design economy? Will the return on investment pay for itself? Everyone has a different approach, a different motivation I suppose.

[7milesout]

I really don't know and can't speculate too much. Somewhere, probably here on this forum, I read that the fuel injection as part of engine management is programmed from the factory for certain operating parameters. A change any one part of the air/fuel equation would require reprogramming. Similarly, some changes will not see their full potential unless other similar changes are implemented. A change in the mechanical valve timing won't really make its full impact unless the air intake is modified to allow more airflow - this can include the throttle body, the snorkel, the intake manifold - whatever. Same goes with the exhaust - changes to the exhaust won't have their full potential unless the air intake is addressed and the fuel delivery as well.



I get the idea that people like to fiddle with their toys & make modifications. A lot of money can be spent on a car. For what? It reminds me of a conversation I had with a SCCA driver years ago. He said every weekend you're driving to a race somewhere, often taking time off work if the race is far away. Spend the weekend tweaking & beating up on whatever you're driving. The rest of the week is spent underneath the car throwing money at it - oil changes, fuel, brakes, tires, and whatever broke over the weekend. His summary went like this:

"Want to make a small fortune in racing? Start with a large fortune."

Unless the driver is talented enough to climb the ranks winning races & getting sponsors, racing becomes an expensive hobby.

I know we're not exactly talking about racing, but making modifications like this always reminds me of how much money can be spent on cars and that SCCA driver's summary about his hobby.

The Mirage works great as it is for what it is - basic, economical, reliable transportation. Will the modification further improve on the design economy? Will the return on investment pay for itself? Everyone has a different approach, a different motivation I suppose.

I think we are in 100% agreement on all the above. I raced motorcycles when I was early to mid 20's. It cost me $700 to $850 per weekend (not including the cost of the bike itself). And that was in the mid to late 90's. So that's what maybe close to $2,000 a weekend in today's money?

And that's the way I saw it. I saw it as, hey, I'm not in the top 1% so as fun as this is, I'm just shedding money. So I capped it off after a couple 3 years or so. It was a good life experience ... but these days, I'd rather have that money back. Oh well.

And I relate a lot of my car thinking back to racing. In one form or the other. For instance, I don't want to make a change to my Blueberry's exhaust ... without taking it to the dragstrip and getting data (before and after). Not that the data matters all that much, but the engineer in me wants to know if I'm adding power or taking it away.

Anywho - I'm interested in these cams, but would need to know a lot more before I'd bother with them. And I'd also need to be outside of warranty. So I have a few years left on that.

[sunbeam]

All valid points above.

It looks like there will be a mirage camshaft post when they get installed.

I would expect a re-tune to be needed. There is someone nearby with experience in this, would not attempt myself.

If you increase the power at each rpm, you can either travel the same speed at lower rpm, or travel faster at each rpm.

So in a sense, it is a fuel economy mod because at 100km/hr you should be running at a lower rpm.