Took my block, crank and rods to the machine shop today. He's going to check it all out and get ready to prep the block and crank. It's a 454 from a 76 silverado, that's been bored .030 over. I'm looking to go with 781's, with stock size valve's, and I'm wondering what would be a good cam and piston selection. I'm not building a race motor, just a solid mid-range street motor. I'm probably looking around 9:5-1 to 10:0-1 compression, with a dual plane manifold and a 750-780 holley vac. secondary. What are your reccomendations on manifolds as well as header size? I'm interested in what combo's worked for you. Thanks for the replies. Dave

Dave,you'll want a piston with a .270 dome to get decent compression with 781's (your target 9.5 to 10 to 1)Performer RPM intake and 1 3/4" primary/3" collector

mr 4speed, thanks for your reply. Do you reccomend a specific brand of piston, I've seen some kits that include pistons, rings,bearings and all the neccesary compononts. Was thinking about ordering one of these, once I get the specifics on my motor.

I've been looking at cam kits, (cam, lifters, springs, locks, retainers). Been thinking Crane or UD, anyone got a suggestion. Like I said, just looking for a good solid street motor. Your suggestions or experiance would be appreciated

Dave,if you want hypertectic pistons,go with Speed Pro or Keith Black,but remember,you want a .270 dome.If you shave your heads a little,and don't mind lower compression,you could use a .100 dome and have about 8.8-9.0 to 1 with your 781's
For a cam,anything in the 220-230ish dur. @ .050,500-550 lift,112 or 110 LSA

I think i'd stick with forged pistons in any BBC. Any minor detonation, which is common with the large combustion chambers, and a hyperutectic piston will break. A piston is not the place to cheap out.

My combo has over 8,000 miles on it with domed hypertectics...no problems as of yet,nor are any anticipated at my power/ET level either.We're talking a nice basic street motor here..I've put together cast flat top 454's with closed chamber heads and cast pistons 402's that ran fine for years with no problems..hypers are a nice upgrade.
My 454 cost me $2500..maximum bang for the buck and reliablity for that dollar

If you're making LOTS of power , NO2, forced induction, or swinging the thing above 7000, then forged are REQUIRED. If its a street, 5500 rpm deal, cast pistons will be ok and ALOT cheaper. Harold's alot like me, in the 70s, we NEVER used cast slugs in any performance application. But metallurgy is a bit better these days.

Both large and small chambers will detonate, that's not an issue. Its primarily about DCR, and some about quench.

My comment directly to Dave. Hopefully you have a good machinist. I would ask HIM which kits to buy, or even get one through him. I can tell you that most machinists don't like customers bringing in Ebay specials or 'deals' that cause troubles which cost money. Even though my machnist was no race engine guy, he sure knew the good, the bad, and the ugly when it came to kits and components. I'm sure yours does too. You should be asking him this question.

Between Chris and I, I think we have two EXCELLENT bbc street cams. His, a more mellow hyd grind that will idle at 15+" of Hg, mine a bit more rumpity solid that will idle at 12" or so of Hg. Both Harold's grinds now available through Lunati, both 10:1 compression cams, and both a bit smaller than you might think by their performance.

Cam selection , IMHO, is in large part a function of the intended operating range of the engine, i.e. gearing,, converter, tranny, etc.

Check out these pistons
http://store.summitracing.com/partdetail.asp?part=UEM-KB257030-8&N=120

click on technical for compression info

I am running a .060 over 454 with open chamber oval port heads. I cut the heads for larger valves and did some very mild port work in the bowls. I am running TRW(Speed Pro) forged pistons, and with the 119cc chambers I should be right at 10.25:1. My cam is a dual pattern cam from Crane that specs out at 226(I) and 236(E) degrees of duration at .050 valve lift, and .525(I) .550(E) lift at the valve. I am running Comp Cams roller tip rockers and crane push rods. The intake is an Edelbrock performer RPM and the carb is a 750 Holley double pumper.

This combination proves to be very stout and streetable. I have not had a chance to time the car, but it is FAST!

my $.02

Yes, the Crane PowerMax 286 is an excellent choice for a 10:1 motor. 112 lsa, nice idle, etc.

You should here the 286 in a 408 motor. Turns a lot of heads cruising into the parking lot at cruise night. Best thing, the power is dead on by 2500 - with a 3000 converter this sucker is on full power right where the converter hits. On a 454 motor I like the looks of the Lunati/UD 288/296 hydraulic on a 110. If I get my 408 set up to hook up, I may even consider going to it in the 408 to add some more mid range and top end.

Thanks for all the help. I'm thinking that the hyper piston's are what I'm going with.

427l88 I'm definitly listening to my machinist, I just took my block to him for inspection. Soon we'll start discussing particular's, and I just want to be able to have a somewhat intelligent conversation with him. I'm just absorbing all the info and possibilities.

I'm thinking that the crane 286 is sounding pretty good, want to get a matched kit if possible. My deal with the machine shop is that we'll decide on a combo, then I'll supply all the part's. His shop doe's mostly block prep for the local deisel repair shop's, but he's doing my motor as a favor to my friend who is a ase mechanic at a local chevy dealership. So he really doesn't want to waste time looking for my part's. Thank's for the help, and keep the idea's coming. Dave

Well, got the report from the machine shop today. Block is good and the crank is shot. Take a look at the estimate for the machine work.
$85.00 to clean,magnaflux,inspect block.
$170.00 to bore and hone to .060
$80.00 to install cam bearings and freeze plugs
$144.00 to recondition the rods
$300.00 for a new crank that's ready to go
$300.00 for sealed power hyperuetectic pistons
$50.00 to press the rod pins
$200.00 to balance
$50.00 for ARP rod bolts

Plus a 10% buddy cash discount graemlins/thumbsup.gif
What do you guy's think of this?

I'm also looking for more opinions on the powermax 286, as I think that it is what I'm going with.

What $300.00 sealed power hyperuetectic pistons?
Dome size?

If you'd ever consider a solid, consider the Lunati A3. Same kinda deal as the Crane on at oh, 2800 and it makes POWER! The idle sounds like Van Halen's "Teacher". Good enough to push a heavy barge to 118.5 in the 1/4. Got some snot to it. 440 ci is all to boot.

Originally posted by 71metbu:

$300.00 for sealed power hyperuetectic pistons
You could buy forged pistons from Jegs or Summit for $20 more.

The rest of the quote sounds about right.

71metbu

Who is going to assemble this? I only ask because you did not list anything for resurfacing the deck. On the next motor I do, I am going to have the basic block work done (bore and hone), bring the block back home and install the crank and the pistons on the 4 corners, then measure the actual assembled deck ht.. I will then have the block decked to zero deck, have the cam bearing installed, bring it back home and clean and assemble it. Basically an extra trip, but worth the time and effort, at least from my view.

I would agree with GRN69CHV on having it near 0 deack. I wish I would have done it on my 408 sb. I thought they could deck it w/o the pistons rods etc. I thought some other measurement would allow for 0 deck. I found out after the other work was done and I had it most of the way together.

I had KB203 in my 454 first time around. No problems except with 781 compression was lower than I should have had. Would be great for closed or semi closed chamber heads, or a milder 454. I still have them on rods with ARP bolts. One rod needs checked for size due to a bearing started to turn/spin. It made it 1/4 around.

My 489 now has a Comp 280. I should have gone larger hyd or hyd roller from Harold/Lunati.

I had a nice 274 XE in it. Very crisp cam. I still have it too. It has maybe 3000 miles on it. I would go with bigger valves if I were you. Mine was not that much more for valves from Competition Products. They are SS and not that much cash or work to have them put in.

I'm not sure of the model # on the piston's.(Don't remember, I had too much going on at the moment, I'll find out and post it though) I believe they were .100 dome. We looked in his piston catalog, and it stated that the 781 head has a 106 or 109cc chamber.That was driving the compression up to around 10.75:1, with the KB .270 dome piston. His opinion is that the sealed power has more meat around the pin area, he can get me a great deal on either. Some things are on hold till I get the actual heads in hand, and we'll go from there. So that is what I'll do now, got to call FRYNTYR and go pick up the heads. Should have more info fri. eve. Thanks for the help, keep it coming. It's really helping me get this done. Dave

You really want to cc those heads before you order pistons. Mine are 119cc!!! Had to go with .270 pop ups.

Joe

Yup, not doing anymore till I get the heads. Heard alot of people say they are 119cc. So I'll just wait till I get them.

Got the heads today. graemlins/hurray.gif Stock, uncut 781's, thanks FRYNTYTR. 119cc, so .270 pop up's it will be. So my question now is, do I need hardened seats, what kind of valve guides do I need? Exactly what gains would be made from bigger valves? Not going to be doing the heads quite yet, but need to start making plans. let's hear it, thanks for the help. Dave

I wouldn't bother with hardened seats..go for the 2.19/1.988 valves though..check here for some good deals:
www.competitionproducts.com (http://www.competitionproducts.com)

We had a little confusion, wally's piston suppliers book listed the 781's as being 109 cc. I kept telling him that they were 119, so we cc'd them and they are 119. Going to go with the KB .250 domed piston's. we're going to check for zero deck, and see where it's at. Soooo, I still can't make up my mind. Is the crane 286 what I want or should I go for more?

10:25-1 compression
781 heads
performer rpm intake
holley 750 vac sec
turbo 400
3:73 posi 12 bolt rear

Still just loking for a good solid street, but don't want to have any problem's with any ricer's. :D Should I look into a harold cam? What about a solid or hyd. roller? Need more info so that I can make a decision soon. Thanks for the help. Dave