302 Flat Top Pistons - Team Camaro Tech
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post #1 of 18 (permalink) Old Sep 11th, 04, 01:32 PM Thread Starter
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Tony
 
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anybody runing these with the 30-30 cam its got
stock heads with manifolds I have a chance to
buy it just wondering if it would run ok
Thanks
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post #2 of 18 (permalink) Old Sep 11th, 04, 03:27 PM
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Tony, it is just my observation from reading what knowledgeable engine builders say on this topic, but the 302 needs the 11:1 compresion that the pop-up pistons give to run the 30-30 cam. I will know how 11:1 runs on California gas in a couple of months. My 302 is on the engine stand waiting for me to get some time (and parts) to put it in.

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post #3 of 18 (permalink) Old Sep 11th, 04, 03:48 PM Thread Starter
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Gary I've got a chance to buy the motor it's been
together about a year & a half he's decided to
go with a crate motor.Though I might buy it &
put mine in storage sense its the oringial
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post #4 of 18 (permalink) Old Sep 11th, 04, 04:55 PM
 
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If it's a 302 with flat-tops and a real 30-30 cam and about 66 cc big valve heads, It ain't gonna run very good at all, imho.....

Compression should be down around say 8.4 to 8.8 depending if it has .020" thick shims or .039" composite headgaskets so the dynamic compression ratio will be about a low from 5.15 to 5.38 at an intake valve closing point of 89!!!! (I used 314 for the good old 30-30 cam's advertised duration instead of the totally out to lunch GM number of 346. Pat K. say's 304 but I donno???)...

Whatever the number is the DCR is in the toilet!! And that was the trouble with the 8 to 1 CR., 283 motor I have b/c it had a 308 hy- cam in it!! Same deal!!!!!!

The sucker needs to be a true 11 to 1 CR. and then the little bugger will really get right up and talk to you!!

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post #5 of 18 (permalink) Old Sep 11th, 04, 05:56 PM Thread Starter
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pdg67 did you run this on a desk top dyno. I'll be running 4.10 with a m-20 maybe just a cam
change would help?
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post #6 of 18 (permalink) Old Sep 11th, 04, 07:23 PM
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If it's a real DZ and a good price go for it. Change the pistons or the cam though. Maybe the compression is why the current owner wants to change. Pdq will set you straight.

"Government is not reason; it is not eloquent; it is force. Like fire, it is a dangerous servant and a fearful master." ..... George Washington

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post #7 of 18 (permalink) Old Sep 11th, 04, 07:23 PM
 
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At 8.75 to 1 CR, a solid version of a good old Crane 266/210 Energizer would be about it I'm afraid... Or in a more modern cam, CC's XS262S at 262/224/268230, 110/106, .477"/.488" gross lift and lash should be .016"/.016 per them.

OK, here goes through D2k, at 8.75CR., a 780 carb. and dual plane, 30-30 cam, stock pocket ported big valve heads and small tube open headers; 6000rpm, hp is 346, 6500, 362hp at 7000, 369hp at 7500 rpm it's 377hp and finally, 363hp at 8,000rpm..

T is 284 at 4500, 300 at 5000, 306 at 5500 and 303t at 6,000rpm...

IMHO, very low for the highwinding little bugger!! It's down, per D2k, about 40hp and 26 pound foot at both peaks from an 11 to 1 motor!!

And if it really closer to 8 to 1 CR., it'd down more.. Like 56hp and 36 t at both peaks...

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post #8 of 18 (permalink) Old Sep 11th, 04, 08:03 PM Thread Starter
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Yes its a real DZ he's had it since the early
80's every things right but the pistons & carb
it's a 650 holly mech 2nd's .030 pistons maybe
losing 50 hp is not that bad should run on
about any pump gas & still spin the back tires
what do you guy thing and thanks for the help
by the way 4000.00 for the motor but it the right
manifolds & dist
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post #9 of 18 (permalink) Old Sep 12th, 04, 07:01 AM
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maybe get some different heads for it with smaller chambers- what kind of compression would some L98 heads give you? they have a really small chamber, and could maybe be milled down some if need be, as well as run with some really thin gaskets or something to get you your compression back up there. plus, 10:1 with flat tops would be better than 11:1 with po up pistons, anyways.

you don't plan sincerity.
you have to make it up on the spot.

wanna hear about 20 years ago when i was too smart to know any better?
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post #10 of 18 (permalink) Old Sep 12th, 04, 09:03 AM
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Tony,

Be careful. Double check the crankshaft to be sure it is a 302. The rear flange will have a single notch about the size of your thumb on a round flange. I have never seen a flat top 302 piston so I am a little skeptical.

The 302 with a "30-30" cam will run like crap with flat tops anway. You need 11:1 for that cam to run right. It would be lazy at any RPM with about 8.5 C/R

I have mine at 11:1 using pump gas and it works fine that way.

-Mark.
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post #11 of 18 (permalink) Old Sep 12th, 04, 09:06 AM
 
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they sell 50 cc big valve heads over at Powerhouse if you are interested in getting her up to about 10.89 to 1 using .020" shims? 11.06 with .015" shims. (-4cc valve notches???)..

Or 55 cc heads wll get you up to about 10.17 to 1..

305HO, -601 heads if they are a measured 58 cc's will get you to 9.78 CR....

Take your pick..

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post #12 of 18 (permalink) Old Sep 12th, 04, 09:13 AM Thread Starter
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The crank is a 1178 a good friend has the motor
he ordered the pistons from Wiseco wonder how
much can be took off stock heads
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post #13 of 18 (permalink) Old Sep 12th, 04, 01:38 PM
 
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Down until you almost get into the top of the intake valve flat, but angled alot more.

I personally wouldn't plane them that much just b/c of intake fit crap and pushrod juggling too.

When done, stuff ends up being for a specific combination so ends up causing problems if/when the stuff ever hits the swap circuit.

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post #14 of 18 (permalink) Old Sep 12th, 04, 01:50 PM Thread Starter
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pdg67 thanks for all the help.He dropped on the
price.You think it'll work now for a driver its
ready to drop in.Not going racing just driving
around town should have enough power to spin the
tires maybe.If you don't think it will it won't
be any fun at all
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post #15 of 18 (permalink) Old Sep 12th, 04, 02:45 PM Thread Starter
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pdg67 you have mail

'69 Frost Green Z/28
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