Considering changing cams and looking for input.

[cwdaniel]

1st the engine details: 2275/76, 94mm bore, 82mm stroke, .08 deck shims around 9:1 compression with 55cc CB 42/37.5 heads, Engle TCS10 Cam, 1.25 rockers, Dual IDF 44’s I built this several years ago for use in a sandrail. The thinking was it would get a turbo eventually, but never got around to it. It runs strong as is.

Had a valve and piston conflict and now have it down for repairs and refresh. The lifters have some pitting probably due to not knowing about the zinc problem early on. So thinking about a new cam.

What I would like is to get a little more low end out of it and still be turbo ready when the time comes.

Possible?

[jfats808]

[ps2375]

A CR of 9.0 and up doesn't seem so "turbo ready" to me.

[cwdaniel]

Doh! typos corrected and 1.25 rocker info added

[mark tucker]

.035~.040" deck, add shims or change pistons when turbo finds it's way home,I dont have a clue what a ts 10 cam is so...

[vugbug68]

[theDrew]

[vwracerdave]

Carbs or turbo, build it now the way it will stay. If you want a turbo jump in and get it now. Don't ever half ass an engine thinking you'll settle for less now and MAYBE get a chance to upgrade it later. Most times later never happens.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[ps2375]

Well said. Generally N/A or F/I builds are different directions on major components.

[deadkombi]

Nothing wrong with an W120 if your not buying a turbo yet. Then you can still use your 1.25 rockers and add turbo and drop compression later if you decide.

[cwdaniel]

Okay let me add some more info. The engine specs followed the advice of a “VW turbo savvy” friend. Checking back into the archives I see that the heads are actually 60cc. And the .08 shims were originally .09. I think that got changed during a top end rework because they were available and the compression bump wasn’t much.

I’m seeing the build it to suit it camp chime in. I get it, and may just elect to build to the naturally aspirated side.

I also see some good input for maintaining the more “versatile” configuration.

One thing that I’m not familiar with is the use of the deck shims to change “throttle response”? So cutting the deck shim down adds low end? “snappyness”? Would adding head volume for a more turbo friendly compression ratio cancel the improvement from a thinner shim?

I’m trying not to dump another bushel of cash into this unexpected repair, so still no turbo at this point. I have to get new heads and a cam, the rest I have spares available.

[ps2375]

Shims effectively do the same thing as "head volume", the "snappiness" comes from a higher CR. So, CR is changed by more cc's in the head or in a larger deck height(thicker cylinder shims).

I think you'll be happier if you build motor for one or the other induction. A compromised build will lead to compromised performance.

[cwdaniel]

Thought processes are leading to build it back to a focus on naturally aspirated. Been given some other advice on how to do that.

CB Panchito heads CC'd to get to a 9.5 CR combined with a Engle W120 cam.

All else remains the same.

Opinions?

[ps2375]

Deck shims do not equal Deck Height. There have been many post in this thread and on this site for what DH to target.

[Brian_e]

CNC Panchitos, 10:1 and a Web 86B. No more then .050" deck height, and make sure the manifolds are ported all the way up, not just match ported.

You didn't mention what you have for exhaust, but a merged 1 5/8" would be needed.

Brian

[cwdaniel]

Exhaust is something like this. 1-5/8 OD tubes.

http://www.jbugs.com/product/3753.html

[mark tucker]

hmm I want to have a turbo but dont have it yet so Ill build a turd and in ten years or so add the turbo......like davy said build it for what it is now. then build the turbo motor for swap out when you need it.

[cwdaniel]

[vugbug68]

[vugbug68]