Warmed-over 1600: What can cast pistons handle

[QPP]

Hello,

First of all, I am a starving college student 

I rebuilt my 1600 engine a while ago, but the heads I used were crap all around, and finally a spark plug blew out soon after the rebuild.  Thread was not even fixable on the heads.

Basically, everything is rebuilt in the engine except the heads (the clutch.pressure plate are knew 1700lbs).  Everything internal is stock :non-counterweighted crank, cast 85.5mm pistons, stock cam, pushrods, etc.

In a moment of insane excitement and euphoria (while coming into some funds) I ordered some Steve Tims heads (Stage 1 Oval Port  ), and a w125 cam.  I was gonna build a temporary 1600 screamer out of this thing (school isn't that far) with the intention of upgrading everything to a 1915 in the not so distant future.

Plans fell through (and now I have almost no money for this thing as most of my money goes for school and school related things) so now I have these awesome heads coming in, a W125 cam, Dual 40DRLA Dellortos, but a completely stock motor awaiting it all.

I am not hesitant to bolt the heads on along with some 40 DRLA Dells I have with the stock cam.  I'm just wondering if should up the compression or not.  How much can stock cast pistons handle?  I don't plan on racing with this engine, I just want to have a temporarily not-so-bad-ass engine that I can floor and feel giddy like I do on my CBR600.  Then, as i save up and buy parts piece by piece, I will upgrade to the 1915 I want.

Or should I go ahead and install the heads, W125, Dells, and see what happens!?

[Sam]

the 125 cam would thrash your enternals by letting the engine rev way past the 5700 max of the crankshaft. Also it doesn't make enough bottom end for a driver in that size of engine.

I would bolt the heads and carbs on and try to find a used set of 1.25 rockers and some chromolly pushrods.    Remember, don't try to run a set of heads with heavy springs with stock aluminum pushrods. Leave the compression alone, a stock cam will make  pretty high dynamic compression, so you would need some higher octane fuel at a way lower compression than the 125.

The engine may run a little funny with the heads and carbs on it, but it will run better than stock forsure.

[QPP]

I knew I should have gotten a tamer cam.  Would a W110 or even a W120 be ok?  Or would that still be too much cam?

[Sam]

a 110 would be OK, but the ratio rockers would be good and keep you from reving the stock bottom end too high. The 125 will be OK in a bigger engine later.

[John P]

Good advice above. I would do a stock cam + used 1.4 ratio rockers. Drive and enjoy.

Save that cam for when you increase the displacement. 

My 1.5 cents.

J