[rollie715]

I attended a swap meet in Mt Vernon Wa today where I picked up a nice set of used 906 Vortec heads. Here's a close up of one of the combustion chambers:


Here's a shot of some pistons I'm thinking of getting:


Notice the similarities between the head combustion chamber shape and the top of the piston. My theory is since I need to lower the compression ratio a little I will need some kind of dished pistons. This particular one looks like a cross between a D-Dish with valve reliefs and a flat top in the area where the corrosponding flat area is in the head. My theory is that the larger the flat area where the quenching occurs the better it will function and that the dished area below the head chamber is the right place to add the extra cc's and still ressemble an efficient chamber.

This particular piston, the Keith Black KB193-030 (assuming a 0.030 oversize bore) as found at Summit at : KB193 Pistons has a 12cc dish which when blocked decked for a 0.040 quench assuming 67cc measured head gives me a static compression ratio of 9.32 and with a cam advertised Intake Closing timing Angle of 56 which is common for many of the mild cams I've been looking at results in a dynamic compression ratio of 7.93 which according to what I've been reading is right in the ballpark for where I want to be when running regular 87 octane gas.

I think I'm getting close to a workable combination.

I plan to do a cc check on the heads for final calculations, and probably deck the block after dry assembling the parts to get precise piston to deck height measurements. Also will likely need to work the heads a little to increase the valve lift limits.

I've been reviewing various camshafts, but still have a ways to go, to understand all the options. Ideally I want an efficient mix of low end torque and mileage.

From what I see so far, I'm guessing this engine should produce horsepower in the mid 300's at around 4500rpm and torque in the mid 400's at about 3500rpm.

Still a ways to got, but I think I'm making progress and enjoying the entire journey. Thanks again for all your input. It is really helping me.

[rollie715]

After lots of reading on the internet, I am getting very close to a plan for my engine build. Many of you on this site have influenced and taught me (I don't want to name names, as I will miss someone), as well as people on other sites, particularly a member of clubhotrod.com named techinspector1.

Here's a thread he commented on that just about fits my my own build:
355 Daily Driver

Just to repeat myself, my goal is a mild, good idling, good mileage, daily driver, runs cheap gas, good low end torque pushing an auto tranny.
So far this looks like a 9:1 compression, 350+hp, 450+torque

The shopping has begun! So far I have purchased the following: (just hope it will all work together)

Used 350 from an 89 C1500 Pickup. Block is roller ready except the spider mounting risers need drilled and tapped. Including 2 700r4 trannys, 1 low mileage and 1 recent rebuild. found on Craigslist, Price $300

Estimated machine shop costs may be:
Block Hot Tank, $75
Cylinder Bore, $200
Block Decked, $150
Crank Ground, $140

Used Vortec 906 heads. Low mileage, needs no work, except I plan to mod to allow a higher lift cam. found at swap meet, Price $275

Comp Cam beehive spring kit including 26915-16 springs, 787-16 steel retainers, and 648-16 valve locks. Claims to allow up to .600" lift which should work fine with my new cam which needs .500" lift. Ebay from Atlantic Speed, Price $249

Blue Viton Valve Seals from Alex's parts on Ebay, Price $19

Spider, dogbones, and cam retainer plate, (my original engine was flat tappets, but mostly roller ready) from SkipWhite on Ebay, Price $71

GM Performance 12499225 hydraulic roller lifters from Jegs on Ebay, Price $135

GM Performance 12371043 single roller timing chain kit from Jegs on Ebay, Price $60

Comp Cam 08-410-8 build 260HR camshaft, Magnum series, very mild, should be gentle on valve train, new from private party on Ebay, Price $220

Edelbrock 2716 Performer EPS Vortec intake manifold, cast finish, I chose EPS over RPM, as I wanted low end torque and not high rpm, US Parts on Ebay, Price $188

Items I haven't purchased yet, but am really close to are:

Pistons, D shaped dish with good flat area in the quench area, about 18cc dish to reach my intended CR of 9:1. Considering the Keith Black KB142.

Head gasket, Felpro Q1003 .041 compressed (requires a 9.000 deck), or GM 10105117 .028 which may be a better choice as it would likely fit better with a 9.013 deck height and .040 squish.

Connecting Rods, 5.7", should I reuse original or buy new?

Headers, Full length 1-5/8 to 3-bolt 3" collector. Not sure of best route, but considering the cheap ones from Summit, Price $110

Your comments are always welcome, as I am making this up as I go from what I learn.

[ap72]

I know its too late, but in the future you can get the spider, retainers, lifters, and pushrods from a JY for about $25. It would have saved you a few hundred dollars. Also, ls2 valvesprings would have been more than adequate, which would have also saved you about a hundred bucks.

I don't know if you're open to using used parts but your build could have been done for about a third of the cost and made the same power, something to keep in mind down the road.

[louis165]

Have you checked the block to make sure it is set up for a roller cam ? I have a 90 truck block and it wasn't a roller block

[rollie715]

Originally Posted by louis165

Have you checked the block to make sure it is set up for a roller cam ? I have a 90 truck block and it wasn't a roller block

Yes, the dogbone area is machined, the front camshaft retainer surface and holes are drilled and tapped, and it has risers where the spider would mount. The only thing I can see that it needs is to drill and tap the spider mounting risers. I have a spider and dog bones and they fit correctly in place. I think I posted a couple pics of those areas in an earlier post on this same thread.

Here's the pics again:


Poor pic but shows area.