The heads depend on your performance goals and pockets. The aluminum heads will definitely give you an edge in the higher performance area, but the Gs will be quite adequate for the street. The testing done so far indicates that the aluminum heads will even improve the low end when compared to as cast G heads. However, I haven't yet heard any real world performance reviews when used on a mild street engine.

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http://forums.y-blocksforever.com/Topic44066-11-1.aspx

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In the dyno graphs, testing starts at 2500rpm and at that point, torque is better, but what happens below that, where a street engine will spend most of its time. Is it worthwhile for you? Only you can decide.


Lawrenceville, GA

No info about duration at .050.  I'll try and put up some pics of the spec card on the cam and maybe a shot of the pistons and see what the concencus is on condition to run them.

So now back to the heads, should I send them in and have them worked or line up on the aluminum ones?

My first action was to take the block in have it cleaned, magnafluxed?, and sonic tested to make sure it is good to go.  Then I was going to look into boring and surfacing and if affordable or neccessary line honed and have the crank polished and work on putting together a short block.  Sound like a plan?

That's not too big at all. It's a dual pattern with more duration on the exhaust, 274 intake, 284 exhaust.. I think you have the exhaust events backwards. Does it say anything about the duration at .050"?


Lawrenceville, GA

I dont know what I was thinking, I know stroke is controlled by the crank, dumb moment.  I need to check those pistons, I'm not used to using a used piston, in harleys we really dont get the chance, the pistons usually are ruined.  I got the specs on that cam also.  Its an Isky cam, #BL #4.  Intake opens 28, closes 66.  Exhaust oepns 28, closes 76.  Valve clearance is .018, lift is .420  Seems a little big to me for a street cam, but thats why I'm here.

You can use the 272 rods with the 312 crank with special pistons, or you can machine the tops of standard flat top pistons .070 to use the longer rods.  Longer rods will not increase the stroke, stroke is determined by the crankshaft.

John - "The Hoosier Hurricane"

If the the .030 over pistons are good, why not go with them & the stk 312 rods? Displacement would be 317 cu in. Custom pistons are going to be fairly costly...

Paul

So I can use the longer rods, say out of a 272, would that increase the stroke even more, but would need a custom piston to work, is this correct?  Yeah, I picked up on scrub=cheby, thanks.

For the new guy, scrub = Chevy.


Lawrenceville, GA

A set of fully prepped truck rods with new bolts are adequate for most street driven purposes and can be had in both the common Y-Block lengths (long:292 & short:312).  If going with any kind of custom piston, then make it a point to use the longest length connecting rod possible.

 

As far as I know, John Mummert has the only ‘new’ replacement connecting rods for the Y.  As another alternative, aftermarket rods for the scrub engines in both H-beam and I-beam designs can be fitted to the Y with some work but typically requires a custom piston or reworking a readily available piston so that both the pin size and pin location are correct.  These same aftermarket rods also requires that the crankshaft rod journals be turned down to a scrub journal size and the rod widths themselves being trimmed down to work on a Y crankshaft.

Lorena, Texas (South of Waco)

Not really necessary when building a good street engine, even ok with some strip use but I would update the rod bolts to ARPs or something of a better grade than factory.

-Gary Burnette-