Thread: stock SBC heads

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the pistons in the kit are flat top, www.SDPC2000.com part no, MKF630C

Something's wrong. My Scoggin-Dickey catalog shows the MKF630C kit as using Sealed Power forged pistons for $529.99, but the website shows a price of $319.95. My catalog shows hypereutectic piston kits for $319.95 @ a c.r. of 8.3:1 and a 8.0:1 kit with cast pistons for $289.95.

hmmm damn, i knew it sounded too good for 320

Well I am hoping my 882 heads from a '76 Corvette will give good performance and reasonable mpg since they originally appeared during a previous gas crunch.

http://chevyhiperformance.com/techarticles/41598/

There is an article giving specs and comparisons of the 882s to other heads. I originally became interested in an article in Hot Rod, December 1995 which had a budget buildup using a H.C. Master Kit rebuild with flat top pistons and an Edelbrock Performer intake to obtain 303 H.P. at 5000 rpm with 295 ft. lb. at 1500 rpm using a rather long cam (in my opinion) which was their standard hot rod grind with 280/290 duration and 0.443/0.465 lift using the 882 heads and standard 1.5 (?) rockers.
I opted for a much shorter "Street cam" from Crane (194/204 @0.050 and 0.398/0.410) to get mileage but then I added 1.6 roller-tip rockers to get slightly longer duration and a little more lift but mainly some faster valve action at low rpm for torque while in OD high gear. I am using the intake ports unchanged but shaved the heads to get 73 cc chambers and paid (a lot) to get the exhaust ports smoothed professionally along with a 3-angle valve job. OVerall it was only $300 to rebuild the heads with the valve job but the extra $200 for the exhaust porting meant I could have bought Vortec heads for the same amount. Anyway I will run these heads for a while and check out the performance and mpg with the OD trans. The main point about the 882s are that you probably run a risk porting the intakes as they are reported to have very thin walls. The exhausts can use some smoothing however. Also note that the flow test shown above on the link indicated that not much is gained in flow after about 0.400" lift, so maybe that is why the longer cam worked holding the valve open longer. Maybe I should just have bought that cam, but I anticipated the rise in gas prices and now I can cut back to 1.5 rockers on the intake if I really need mpg. Also note that the small runners of the 882s restrict high rpm flow BUT help make torque at low rpm.

Don Shillady
Retired Scientist/teen rodder

If this is a street motor, there's nothing wrong with cast pistons. Bore the motor 0.030" and hone it to fit your new pistons. Then bolt the crank (oiled) into the block with the bearings you'll be using and assemble one piston/rod assembly without rings. Use this one assembly and bolt it onto the crank, one at a time on cylinders 1, 2, 7 and 8. Rotate the crank to bring the piston up to top dead center on each of the four corners of the block (1,2,7,8) and measure the top of the piston to the top of the block deck. Record each measurement, then unbolt the crank and bearings and have your machine shop cut both decks of the block so that the pistons will be at zero with the deck. Use a head gasket with a compressed thickness of 0.039". The resulting c.r. will be 8.90:1 with the cast, dished pistons in your MKP630C rebuild kit, $289.95. Tell Scoggin-Dickey that you want a cam with 212 to 216 degrees duration at 0.050" tappet lift.

with a CR and a cam that size will this motor make some decent power numbers?

and how big are the cams for these kits? do you tell them what you want?

It's not gonna be a world beater, but it will make good power with good vacuum, run on crap gas with full ignition timing, and work with a stock converter and tall rear gear.

Yeah, tell them the cam you want. If they won't supply the cam you want, tell them there are other places you can buy kits.

the guy i got the motor from just told me to get a 488 cam will they have that?

Is this same guy gonna help you change the cam to a milder grind after you find that a cam that big won't pull the hat off your head with low c.r.???

Hi, please keep me posted on how you like the 882s and what cam you finally used. I've just bought two sets of 882 heads really cheap and wanted to have one set ported and a 30 degree seat cut in and see what difference it makes in a daily driver. I'm concerned about MPG, because I live in Germany where gas is over twice as expensive. I cracked one of my 041 heads, so thats why I needed new ones and the 882s were the only ones I could find here. 882s are said to be good for low end torque which is what you want in a daily.
Please answer this post on what cam you put in in the end and how well it works. Thanks!
Mad

This sounds like a dog chasing its tail. You might want to back up and start again by telling everyone what you are doing with the heads. What kind of vehicle are you putting it in, the tranny, the induction system,etc.
Are you racing, pulling a boat, four wheeling, drag racing, what?
Your end result goal determines where you start. Then, these guys can be more precise with their answers. Now, let's try again, OK?

right now im just rebuilding a 355 with these heads. i plan on it going into a 3rd gen camaro. as far as induction, holley 750 with a stock 4 barrel intake manifold. the motors gotta be streetable but i plan on racing with it occasionaly

I think bolting on 64cc Vortec heads would be alot more bang for the buck. JMO.