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Old 03-16-2009, 01:55 AM
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fresh sbc 350 build 400 hp poss?



hi im jason i just built a 350 for my lil bro for as grad pres
was wondering if my combo is a good setup here is what i have
1984 trans am aprox weigh 3200 lb with driver
7004r with 3:42 gears

cam ... comp cams extreme energy 12-213 3 h292 244 dur lsa 110

1973 010 hi nickle block 4 bolt main

416 heads fully ported polished "stock valves" intake runner size 2 1/8 X 1.50
200cfm est valve size is 1.85 1.5
bowl blended valves un shrouded removed all the flashing in the exhaust ports
heads are 58cc with a .015 head gasket hit 220 psi in all 8 thinking that's 12:1
pistonsare flat tops are h345np hypers with chrome molly rings

rods are powder metal rods like 1 up from stock like an lt1 rod no name on them

total piston and rod weight are 920g

crank is steel out of a 283 49 lb

the stall in the trans is a 2800 from what i was told from a trans shop cause
the car was a 305 hard to believe that

intake is a edlbrock dual plane rpm air gap performer with a bg speed demon 660 cfm carb

pertronics ditro with accel coil acdelco 45ts

so hopin to hit low 12s

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Last edited by jasont/a83; 03-16-2009 at 02:07 AM.
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Old 03-16-2009, 03:53 AM
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Quote:
Originally Posted by jasont/a83


hi im jason i just built a 350 for my lil bro for as grad pres
was wondering if my combo is a good setup here is what i have
1984 trans am aprox weigh 3200 lb with driver
7004r with 3:42 gears

cam ... comp cams extreme energy 12-213 3 h292 244 dur lsa 110

1973 010 hi nickle block 4 bolt main

416 heads fully ported polished "stock valves" intake runner size 2 1/8 X 1.50
200cfm est valve size is 1.85 1.5
bowl blended valves un shrouded removed all the flashing in the exhaust ports
heads are 58cc with a .015 head gasket hit 220 psi in all 8 thinking that's 12:1
pistonsare flat tops are h345np hypers with chrome molly rings

rods are powder metal rods like 1 up from stock like an lt1 rod no name on them

total piston and rod weight are 920g

crank is steel out of a 283 49 lb

the stall in the trans is a 2800 from what i was told from a trans shop cause
the car was a 305 hard to believe that

intake is a edlbrock dual plane rpm air gap performer with a bg speed demon 660 cfm carb

pertronics ditro with accel coil acdelco 45ts

so hopin to hit low 12s
jason, I don't know what to say.
First you tell us you built a 350. Then you tell us you used a 283 crank. With a stock 4.000" bore in the block, that would make a 302 (that's if you could still find spacer bearings). Bored 0.030" would make it a 306. Then you tell us that you used 350 pistons (H345NP's that have a 1.540" compression height). A 283 crank with 5.7 rod and 1.540 piston would make a stack of 8.740", a little more than a 1/4 inch from what it should be to make a real motor. Now, you could have used a 6.000" rod with a 2.000" big end, but that would put the stack at 9.040", or about 0.015" popped out of the deck at TDC with a nominal block deck height of 9.025". You could still do that with a 0.015" gasket until you started the motor. You'd have zero piston to head clearance and all 8 pistons would crash against the bottoms of the heads and the whole shebang would go downhill from there. About the best you could ever get for static compression ratio with flat-tops in a 302 with 58cc heads is 9.78:1, so now you're telling us that you recorded 220 psi with a 12-213-3 cam that closes the intake valve at 74 degrees ABDC?????????

I was your age once.
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Old 03-16-2009, 04:40 AM
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type o sorry was a 350 crank and yes the cranking pressure was 220
and i did have my engine decked at 0 so when the piston sat in there it was flush with the top of the deck no down the hole bull**** 3.48 x5.7
was the rod and stroke .. as i mentioned the duration at .50 is 244 av is 292
seat to seat

i did all the work i pressed in the pistons in to the rods boy that was fun for doing it the first time have to be quick with that piston pin keep that thing cold the rod nice and hot not glowing never done it before. and i wasn't going to pay some one to heat something up and do the same thing i read up on it and did it only ruined one piston it expanded cause i got the pin stuck in there and over heated the piston and it expanded to 4.030 at the bodom top was still 4.000

btw the engine runs as of yesterday 7:41 pm 03/15/09
found a leak in the front seal .. but it ran real good mini starter has a hard time turning it over think its the starter it self
dose any one know how to get one defective one returned i called and emaild a week ago and they arnt there or something powermaster 9600 starter... ?


ill post a youtube link of the engine running i have a before one ... its really sad
http://www.youtube.com/watch?v=3g-mNPQldX4
thats a before ... i found what that noise was u can hear it when i rev ... every rod barring and main was spun the crank had a 1/8 in groove in it .. pic here

http://viewmorepics.myspace.com/inde...ageID=51739184
and this one too


http://viewmorepics.myspace.com/inde...ageID=51739173

Last edited by jasont/a83; 03-16-2009 at 05:22 AM.
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Old 03-16-2009, 05:40 AM
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This a drag car or street car or both?
Was the 700R4 beefed?
Does the car have T tops?
Is the rear the 7.5?
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Old 03-16-2009, 01:34 PM
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If the piston now comes right exactly flush with the block at TDC you will get trouble using a .015" head gasket as the piston will kiss the head at high rpm.
.015" is not enough clearance between the piston and head deck.

Pull the heads off and install .039" thick head gaskets, before you rev it up.
You'll still have plenty of compression.

With the 292H cam you need full timing at idle.
Lock out the distributor mechanical advance and set the timing at 34-36deg full time.
Use cool heat range non projected tip spark plugs in the 416 heads.
Champion RV8C AC R42T or equal. (.035" gap.)
To get around the hard hot starter cranking with the required base/initial spark timing,
Install a ignition power interupt switch onor under the dash to allow you to spin the hot starter motor over easy, then throw the spark switch and it will fire right up without starter strain.
Make sure you have the OEM GM rear starter mount bracket/brace on the starter or you will snap the starter nose.

You will need to get a 3500-3800 stall torque converter for the big 292H Magnum cam to be all it can be. Some 4.10's would be nice too.

You'll probabily need to blend some 110 octane race gas in with your 92 octane street gas as the cr is quite high. Otherwise you'll have to jet rich and compromise the timing a bit (29 to 34deg) to keep it from destroying itself.
Again .015" is not enough room between the piston and cylinder head.
.038 to .055" is good.

If you worked on the combustion chambers some, the chamber volume will likely be a bit bigger than 58cc now. Should have gone to a larger 1.94" valve but......

Last edited by F-BIRD'88; 03-16-2009 at 01:47 PM.
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Old 03-16-2009, 02:02 PM
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Quote:
Originally Posted by DoubleVision
This a drag car or street car or both?
Was the 700R4 beefed?
Does the car have T tops?
Is the rear the 7.5?
yes both mostly street
700r4 is stock running an extra cooler
yes has t tops

i dont think the piston is going to kiss the head considering the compression distance and ring position i copyd a circle track setup i wish i could of used 1.94 too but dident have the money for it. will be getting a set of dart pro 1 heads this summer

i will be welding in a full roll cage and tying it in to the sub frame connectors

i haven't set time yet
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Old 03-16-2009, 02:11 PM
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piston to head interference has little to do witht he height of the top ring land. If you're truely at zero deck running a .015" gasket you will be buying pistons, rods, and bearings long before you get those heads... Long before you actaully get the car to the first gas station. No one is crazy enough to run that tight of quench on a SBC.
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Old 03-16-2009, 04:05 PM
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That much cam with smogger 305 heads? IMHO, you'd be better off waiting until you have a decent set of heads before even running it.

And, you need to rethink your 0.015" piston to head clearance.

Just use a good quality composite head gasket in the 0.040" neighborhood and you'll be spot-on, quench-wise. It's a no brainer, guy!
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Old 03-17-2009, 12:16 AM
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engine is working good set the time at 32 deg till i change plugs to r42ts
temps are good sits at 200 on the highway 160 at a stop think my radiator is too small for the engine its a single core i will be upgrading that..
i do like the tight quench must not be at 0 like i thought it was i did have it milled but that's when my dad had it and the machine shop went out of bis
should be like 9.24 i only had them surface it to make sure it was flat
i remember it wasn't much tho when i put the pistons in the piston sat flat with the deck tho ... ?
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Old 03-17-2009, 08:24 AM
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[QUOTE=jasont/a83...with chrome molly rings [/QUOTE]Chrome rings or moly (plasma or filled) but not both.

There are steel rings but steel rings have to be coated so they will not scuff. That's where the chrome, moly or gas nitriding comes in.

One last comment on your head gaskets- IMHO, you should re torque the heads after you've heat cycled the engine a few times. Steel shim head gaskets are fairly unforgiving in this regard.
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Old 03-17-2009, 01:09 PM
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ive noticed i have a coolent leak on one side im going to todo tonight ..

Last edited by jasont/a83; 03-17-2009 at 08:43 PM.
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Old 03-17-2009, 02:41 PM
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another thing is wont rev past 4000 i have a hei disto and a demon carb
was fine before engine blew now it wont rev just sorta stalls there @4000
can u blow a power valve on a demon carb cause it has backfired thu there a few times ?
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Old 03-17-2009, 08:42 PM
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well found out that a 650 is too small i put a 85 jet in the main and dident make a difference any one want to buy a carb...? going to a 800 cfm cause of the intake im running is a dual plain ..
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Old 03-17-2009, 09:48 PM
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Jerk those stupid heads off of there and get a set of mid 90s ported vortecs. The 64cc chambers will get your static compression down to something that will live on the street and you'll even gain about 40 horseys to play with.
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Old 03-18-2009, 01:02 AM
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so far no one has said if his combo could make 400 hp
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