Mykk builds a small block

**04SilveradoMykk** · 07-04-2008, 02:53 PM

The tried and true, dime a dozen small block chevy.

So far I don't have a dime into this, so all is well.

::Monster Garage Voice:: FREEBIE!

85-95 LO5 350, one piece rear main, 4 bolt mains, roller cam block w/ TBI heads the first of the "swirl port" heads.

The motor has had a recent rebuild, .030" overbore and crank turned .010"/.010"

more freebies. L31 vortec heads with complete fuel injection. I already removed the poppet spider.

I already tore the block down and discovered why this motor was put on somebodies backburner. Cyl # 5 had an exploded piston, but did minmal damage to the cyl wall. The minor ring scuff will get taken out with another .010" overbore. BTW, I love the use of the flat tappet RV cam in a roller motor.

**04SilveradoMykk** · 07-04-2008, 02:53 PM

I originally intended to throw a stroker crank at this project, but after tearing it down and seeing that a machine shop balanced the rotating assembly I might just keep the crank and with the .040" bore run a 357ci small block. All in the name of empty pockets.

Aside from Cyl # 5 the entire block & heads are in excellent condition. The TBI heads still have the reman heat tabs on them, they are currently up on craigslist. I couldn't get a .002" feeler gauge under a straight edge anywhere on the deck surface. The cylinders have maintained a perfect 4.030" circle without any taper, egging or ring ridge and all of the bearings were un-scuffed. That was a recent rebuild before the mishap. Aparently the story is that the previous owner tossed the TBI for a carb, and had it jetted down so the motor was running consistantly lean & hot. Although I don't see any evidence of over heating.

was bored, so I figured a duplicolor rebuild was in order and dress up while it's on the stand untill I can really get balls deep into it. Nevermind the perimeter bolt VC on centerbolt heads.

So stay tuned for the finished SBC. I'm am tapped out of expendable income for the month of July... so it will be a couple months before I put it back together.

I've given myself a budget of about $1500 total to have this puppy done, most of wich will be in the valve train.

And yes, before you ask. This motor is for my 04. Wait, so why not a LS/LQ based swap like what came in the truck from the factory?

I'll tell you why.

Because the L31 is the perfect candidate for a 4.3L to V8 swap. The fuel injection is practically identical and all of the 4.3L accessory brackets, serpentine belt system & pullies and engine control sensors can all be used on the L31 V8.

Performance parts for the old small block chevy are just a fraction of the cost of LS parts. I can retain a few currently used 4.3L performance parts. The K&N intake can be modified to work with the V8. The 75mm CFM-Tech throttlebody will transfer over. I already have HPTuners to write the v8 tune. The only custom work to be done will be modifying the trucks wiring harness for two more injectors. Exhaust work, I might as well do a set of long tube headers. And a motor mount adapter plate to adjust for the v8 re-located motor mount provisions.

I can play with gasket matching, port & polish and I plan to upgrade the vortec F.I. spider and clearance the valve guides for a high lift cam.

And finally, what custom street machine isn't complete without a small block chevy... I mean, come on ;)

the Desktop Dyno estimated output for a .040" vortec 350, stock crank, with head work and a 260HR cam.

That's pushing the horsepower envelope for that design of fuel injection anyways. I don't know about you but I can live with that kind of power from a daily driver and still maintain 17-24mpg

Cheers ~Mykk

**Cableguy** · 07-04-2008, 10:29 PM

Nice job, Mykk

I'm diggin' your project!

400HP @ 5000RPM...hang on to your false teeth Effie we're gone fly now

**no0b123** · 07-05-2008, 01:04 AM

Awesome, good for you. I wish to do the same someday

**04SilveradoMykk** · 07-10-2008, 10:47 AM

Here's the plan to stab that motor in a truck that never had that engine in the first place.

I have this template to make this plate out of 1/4" steel.

The plate is to be able to use stock SBC motor mounts with an LSx block.

In theory, if I run them in the opposite and mount the plate to the SBC provisions I can use the 4.8/5.3 GMT800 motor mounts.

I just printed out the wiring ECM schematics for a 2002 G Van 5.7L(0411 PCM) and the PCM harness schematics for my 2004 Silverado 4.3L.

Every single pin is identical between the two computers. The V6 PCM has blank pins where the V8 has the two extra injectors. And where the V8 has EGR pins the V6 is blank... however, even thought the V6 & V8 have injectors in the same pins. They are not the same cylinders, I have a feeling that has to do with firing order.

So we'll see, I'll try my current PCM re-wired and re-tuned.... if it doesn't work I'll snag a 0411 PCM.

**Pete95Sierra** · 07-10-2008, 08:44 PM

looks awesome man. cant wait to see how it goes!!!

**04SilveradoMykk** · 07-11-2008, 10:22 AM

Craigslist is great for an engine builder.

Last night a buddy and and I drove down to Phoenix from Prescott (in the worst rain storm) He bought a non-running 1995 Eagle Talon, lol. and I figured I'd find something for myself while we're going down there.

I found a dude who had an entire ZZ4 rotating assembly for cheap!

Forged Crank, Rods, Pistons, Dampener, Flex Plate, Timing Chain Cover, Valve Covers, ZZ4 roller cam, roller rockers all for about the price of a generic Pistons, gaskets, oil pump & freeze plugs rebuild kit.... so score!

**Steve** · 07-11-2008, 10:45 AM

That's an awesome project. Looks like you scored on Craigslist too, keep us updated on the progress! Great job!

**DRMZ28** · 07-11-2008, 03:17 PM

That should be tight when it is done...I was gonna put my LS1 in my truck but...funding came up short haha!

**04SilveradoMykk** · 07-13-2008, 12:22 AM

Made a EGR block off plate today.

Dropped off the ZZ4 parts at my shop. The part number on the cam is actually a GM Performance parts LT4 hot cam. But I'm not sure if I can trust it. The part number on the rocker arm box is for GM Performance 1.6 roller rollers but has stamped steel stockers inside. So I'll put a mic on the cam lobes and see if the lift is matches a LT4 cam or ZZ4 cam.

Going out of state for a week, I'll pick up where I left off when I get back.

Cheers ~Mykk