OST-047: Skippy Replicate

[oldeskewltoy]

Remember Skippy?? http://www.club4ag.com/forums/viewtopic.php?f=16&t=18040&p=128321

A quick refresher, I bought/built Skippy(FX16) to be a commuter. When I bought her the engine was junk, and I did a rebuild with the express purpose to maximize the engines torque curve in an effort to maximize fuel economy by having more power in the mid range to allow a shallower throttle angle while on the highway.......



Well, I ended up not needing the commuter and I put her up for sale. It took a while ($3500 FX16 typically does), but I sold her to 2 people..... One person bought her for her engine.... the other bought her because her chassis was in very good shape. Well, the chassis purchaser doesn't want to give up Skippy's engine! Meanwhile the engine purchaser wants his engine!

The engine purchaser will be using the original Skippy 4AGE for rally purposes....




Sooo... I've been commissioned to replicate Skippy's head..... so the chassis purchaser can also enjoy a FAT torque curve





more to come.....

[jinx]

cool to see a clean street FX16. Sad to see this one get 'unplugged'

so this is a 10.7:1 TVIS bigport .....with TVIS working ?
Torque looks beefy(for a na 1.6) from down low. Would be interesting to see a stock torque curve overlay/comparison
I'd imagine the FX drove strong?

[oldeskewltoy]

cool to see a clean street FX16. Sad to see this one get 'unplugged'

so this is a 10.7:1 TVIS bigport .....with TVIS working ?
Torque looks beefy(for a na 1.6) from down low. Would be interesting to see a stock torque curve overlay/comparison
I'd imagine the FX drove strong?

close enough... (actual is 10.77:1)

how about a side by side????

Dyno on left is admittedly just from an advertisement.... but it is published data. With that said....... ( I hear some of you rolling your eyes.... )




Whether or not you like the above comparison.... The FX drove very strong.... tough to get it to hook up in 1st gear




This head is very dirty... but it is still uncut, and the cast(core) shift isn't too bad








Intake valves aren't too "skanky".... the exhaust on the other hand.... that can't help flow





more to come......

[jinx]

not much to c, engine vs chasis dyno
looks like porting + compression certainly increased output straight accross.... verified by how it drove

FX in photo above looks tough

[oldeskewltoy]

working cylinder 4 intakes first.... followed by #3






more to come......

[mr2mk1hero]

Ha! Awesome story! Glad to hear she went to good hands and will be used properly

[oldeskewltoy]

Intake side.... and chambers now shaped

Ports themselves have changed very little, only a tiny bit of blending, while the bowls and seats got worked - this is to help increase port velocity.








Chambers are all now deshrouded, once it comes back from its valve job, I'll set chamber volumes and finish the chambers





More to come.....

[oldeskewltoy]

Skippy's replicate goes in for its 3 angle... here are the exhaust before - after.....

first the valves... from before clean, to after cleaning (no cut valves yet....)




better flow here already.......



and now the exhaust ports - before, and after.... still through standard gasket





more to come.....

[Rogue-AE95]

Dumb question... is it OK to use used valves? Are there instances when valves shouldn't be reused?

[oldeskewltoy]

Dumb question... is it OK to use used valves? Are there instances when valves shouldn't be reused?

actually... that is a great question.... for the most part - YES, you can reuse the valves. You do have to be aware of a few things when having the valves reconditioned (ground). A few key things are keeping a minimum "margin", grinding the correct angles, along with the actual size of the angles. But the easy answer is yes.


As far as flow is concerned, I did some flow testing on different valves, in ported, and unported heads a few years back - the short answer is a good port with a properly ground stock valve flows as well as a fancier valve in the same port.

As to when the valves should not be reused - bent, or burnt is obvious, as neither will seal when placed against the valve seat. What is less obvious is too thin of a margin - this could lead to valve failure(burning) as too thin of a margin can lead to premature valve failure. Also too thin of a stem can lead to an unstable valve in it's guide - causing poor sealing. Other potential valve faults - distortion.

[Rogue-AE95]

OK. Thanks for the reply!

[oldeskewltoy]

The head is back from its 3 angle, and surfacing




and the valves are back too....






assembly is later this week....

[oldeskewltoy]

assembly is later this week....

[oldeskewltoy]

Clearances set.....