Shim Question

[93rev2sev]

The cam lobe touches almost the whole surface of the shim at some time or another. The shims/buckets aren't stationary. They spin.

Actually, I'm 72% sure that only the center 10mm gets touched by the cam lobe.

 

[K-Dawg]

Well I'm glad that you did the calculations, but I'm 73% sure so I win.

 

[SHObill]

I am 100% sure that the cam lobe touches 95% of the shim surface as the 10mm wide cam lobe makes a path across the 29mm dia. shim, as it spins it also. In reference, the Yamaha bike cam lobes are 14mm wide & also use the same 29mm shim.

 

[1993MTXSHO]

I am 100% sure that the cam lobe touches 95% of the shim surface as the 10mm wide cam lobe makes a path across the 29mm dia. shim, as it spins it also. In reference, the Yamaha bike cam lobes are 14mm wide & also use the same 29mm shim.

ohhhh ok I get it now, when the lobe comes down it touches the outside of the shim and rubs across it... duhhh and I knew it spins so now this all makes sense. But Im still uneasy about the shim material, some people say its ok some don't. Im gunna do some digging and make some phone calls

 

[pjtoledo]

the SHO engine IS an (oversized) motorcycle engine, so the bike parts work just fine.

Perry

 

[yamahaSHO]

ohhhh ok I get it now, when the lobe comes down it touches the outside of the shim and rubs across it... duhhh and I knew it spins so now this all makes sense. But Im still uneasy about the shim material, some people say its ok some don't. Im gunna do some digging and make some phone calls

Just use them... I doubt there is any discernible difference... Probably not any. People have been using new "motorcycle" shims since before I got into SHO's.

 

[Mr Anonymous]

Just use them... I doubt there is any discernible difference... Probably not any. People have been using new "motorcycle" shims since before I got into SHO's.

I can guarantee there is no difference. I've seen countless brand new Ford shims, and they are all the same. Stick 'em in the motor and in about 20 hours they look just like the old ones.

Maybe the next query will be whether or not the color shading of motor oil effects how much power the engine will make!

 

[1993MTXSHO]

I can guarantee there is no difference. I've seen countless brand new Ford shims, and they are all the same. Stick 'em in the motor and in about 20 hours they look just like the old ones.

Maybe the next query will be whether or not the color shading of motor oil effects how much power the engine will make!

maybe it will does how dirty the engine oil effect hp? I always wondered that... I bet if I dump some antifreeze in my oil to thin it out ill make some more hp and keep my block from freezing.

I just don't want to destroy $550 cams thats why I ask, how stupid would I be if i didn't ask and then it destroyed my cams? Im opening the engine back up in 500-1000k miles to re tq everything and re check the shim gaps, so I guess ill use them and see if they look nice an polished then

 

[St Louis SHO]

:laugh_ti:

maybe it will does how dirty the engine oil effect hp? I always wondered that... I bet if I dump some antifreeze in my oil to thin it out ill make some more hp and keep my block from freezing.

 

[Phoenix]

maybe it will does how dirty the engine oil effect hp? I always wondered that

Years ago there was a MM&FF mag article about it. They tested reg oil and dyno'ed it , then dropped the oil and put in Royal purple in the mustang and dyno'ed it again.

Believe it or not , the damn thing gained 5hp.

Would this do the same to your SHO , no idea but it had me convinced and I went Royal purple.

 

[ScottyDsntKno]

The guys on the power block gained 8whp on a LS1 camaro by going to royal purple oil, trans fluid and gear oil. I personally think that most of the power comes from changing dirty old broken down fluid out for new stuff. Any good quality oils and fluids probably net similar gains.

 

[AREA 91]

I gained 12HP by switching to Geico.

 

[K-Dawg]

You'll probably make 6.3 more HP using the smooth shims because there is less friction.

 

[SASHO91]

I gained 12HP by switching to Geico.

:laugh_ti:

I'm no oil specialists, but I did stay at a Holiday Inn Express last night.....

 

[gas it]

Has anybody tried to stack 2 thin shims to make the gap right?

 

[Phoenix]

Has anybody tried to stack 2 thin shims to make the gap right?

That wont hold for 2 cam revolutions. The buckets are just not deep enough.

 

[yamahaSHO]

Is that a serious question?

 

[sdpatt]

Actually, I'm 72% sure that only the center 10mm gets touched by the cam lobe.

I'm 100% sure of this. The cam lobe is curved and touches the shim in a line the width of the cam lobe. That line moves only a few millimeters off center and, as the shim/bucket rotate, draws a wear spot on the center 1 cm (10 mm) of the shim.

 

[1993MTXSHO]

Years ago there was a MM&FF mag article about it. They tested reg oil and dyno'ed it , then dropped the oil and put in Royal purple in the mustang and dyno'ed it again.

Believe it or not , the damn thing gained 5hp.

Would this do the same to your SHO , no idea but it had me convinced and I went Royal purple.

oh yeah, I know that syntietic oil does gain hp, but I was talking dirty vs clean oil of any kind, and it was a joke, dunno if you picked up on that haha

 

[Phoenix]

oh yeah, I know that syntietic oil does gain hp, but I was talking dirty vs clean oil of any kind, and it was a joke, dunno if you picked up on that haha