.030 over 350 chevy build..

[Brucer]

ok i have a goodwrench 350 4 bolt block, crank and rods.. all come out of a high mileage truck and it needs some lovin..

my proposed build.

freshen block
.030 bore block
.010 .010 crank
stock rods with good aftermarket rod bolts

chevy camel hump heads 64cc 2.02x1.6 valves, simple rework the heads valve springs and a 3 angle valve job..

federal mogul master kit
pistons federal mogul hypereutectics final compression 9.72 with 64cc heads with .040 head gasket

camshaft-summit racing brand
.488/.510 .292/.302 with 114deg lobe seperation angle...thats with 1.5 rockers, more than likely would go with 1.6's for a tad more lift and duration..

tunnel ram with 2x450 mechanical secondaries.. msd 6al ignition and..msd distributer(already have these)

tranny turbo350
stall 2800rpm
rearend 9 inch ford-3.90 gear ratio

this sound like a solid build?what kind of power? i'd guess a tad over 400hp



any of you guys thats had experience with T's for a while i would definetly like your opinions on practicality of this engine, mainly if it would be to much camshaft for a lightweight T..

thanks brucer

 

[RPM]

Sounds good to me, go for it. 400 hp maybe, need some one with a desk top dyno to plug those numbers in for ya.:rofl:

 

[GT63]

Those heads will need bronze guides installed for unleaded fuel, and I would have them drilled for studs and guide plates. That's what I did to the pair I have for the 327 I'm building for my Dad's project.

That's quite a bit of lift for those heads. The original SBC 302 and 327 motors only had 485 and 447 lift with those heads and made big HP.

400HP? maybe, My 355 cu in SB with a Weiand 142 supercharger made 341 HP at the rear wheels. I saw a couple 383 SBC on a chaisis dyno only make about 250HP.

 

[Mike]

You're going to come up about 2 points light on static compression. I definitely would not go to the 1.6 rockers, as that is only going to aggravate the situation.

A set of heads that old are going to need more than just simple work. Keep your eye on what it will really take to bring them up to snuff and then start comparing that to an aftermarket head. You'll likely find the aftermarket options more attractive than you think.

400 HP at the crank is going to be a real stretch.

 

[Brucer]

Those heads will need bronze guides installed for unleaded fuel, and I would have them drilled for studs and guide plates. That's what I did to the pair I have for the 327 I'm building for my Dad's project.

That's quite a bit of lift for those heads. The original SBC 302 and 327 motors only had 485 and 447 lift with those heads and made big HP.

400HP? maybe, My 355 cu in SB with a Weiand 142 supercharger made 341 HP at the rear wheels. I saw a couple 383 SBC on a chaisis dyno only make about 250HP.

you had a blown smallblock and it only put out 341hp on a chassis dyno. that sounds low, i know you figure about 20% driveline loss but that still seems a tad on the low side .. i have an 04 ram hemi shortbed truck thats puts out 290 rear wheel hp on chassis dyno, all it has is a aftermarket muffler and 3inch single exhaust.. you might need to check for converter slippage maybe..

i built a 355 chevy , trw l2256f forged pistons with world products 67cc heads 2.02/1.6 undercut stainless valves and a 510/525 lift wolverine blueracer cam, with 1.6 rockers stock crank and rods and it made 425hp at like 6200rpm on engine dyno..
no reason you cant get 1+ horsepower per cubic inch from a naturally aspirated engine on pump gas. and you should tell those guys that got 250hp from a 383 to stop building motors and or trying to tune them, cause they arent doing something right, unless they were low compression motors with small cams...

 

[Mike]

i built a 355 chevy , trw l2256f forged pistons with world products 67cc heads 2.02/1.6 undercut stainless valves and a 510/525 lift wolverine blueracer cam, with 1.6 rockers stock crank and rods and it made 425hp at like 6200rpm on engine dyno..

Color me extremely skeptical.

We've been building motors for 35+ years and running them on a SuperFlow dyno for well over 20 years. I know what it takes to make an honest 425 HP and quite frankly, the above combination is going to fall well shy of that number. Or there was a lot more to that combination than you're letting on.

Now there are ways to 'make' HP on a dyno, so the customer gets the hero number he's looking for, but there is a difference in honest HP and what we like to call Texas HP. You can pick a wonderful spring day, with a bluebird sky and an extremely high barometer, then sit down at the console and input a barometric reading of 24.5". (and don't think that trick hasn't been pulled) The correction factor in the dyno computer will start making the corrected numbers look very good. If that's still not good enough, you pull the air temperature probe out of the intake hat and let it hang over the side, so it's right next to a header collector. That is usually good for another 12-15. Keep playing with those tricks and you've suddenly got a 10:1 355 with a wee cam profile that can make 1.2 per inch. Then all you have to do is make sure the customer only sees the corrected numbers and not the observed numbers. If he sees the observed number is barely over 1.0, he's going to walk away, looking at his shoes.

We've been accused of having a 'stingy' dyno room, with the way we pull air into the room. But we've run motors that have come off Reher-Morrison's dyno and have seen numbers within 2. We had a fellow bring us a motor that had just come off Lingenfelter's dyno. The castings were still warm from the last pull up there. We hung it and ran it and the sheets were near duplicates of one another. So we try not to lean too hard on the leakers, when they tell us how stingy our room is.

 

[GT63]

you had a blown smallblock and it only put out 341hp on a chassis dyno. that sounds low, i know you figure about 20% driveline loss but that still seems a tad on the low side .. i have an 04 ram hemi shortbed truck thats puts out 290 rear wheel hp on chassis dyno, all it has is a aftermarket muffler and 3inch single exhaust.. you might need to check for converter slippage maybe..

i built a 355 chevy , trw l2256f forged pistons with world products 67cc heads 2.02/1.6 undercut stainless valves and a 510/525 lift wolverine blueracer cam, with 1.6 rockers stock crank and rods and it made 425hp at like 6200rpm on engine dyno..
no reason you cant get 1+ horsepower per cubic inch from a naturally aspirated engine on pump gas. and you should tell those guys that got 250hp from a 383 to stop building motors and or trying to tune them, cause they arent doing something right, unless they were low compression motors with small cams...

Well the supercharger was only putting out about 3PSI, it's only a Weiand 142 mini-blower. The Dyno sheet did show that I was a little lean, AFR was less the 14:7. I am running a 3200-3500 TCI stall convertor in a TCI TH350 trans. Anything lower and it would surge while standing on the brakes. I'm in the process of upgrading to a 6-71 supercharger with 8PSI and twin Demon carbs. That should liven it up some.

 

[CNC BLOCKS]

You're going to come up about 2 points light on static compression. I definitely would not go to the 1.6 rockers, as that is only going to aggravate the situation.

A set of heads that old are going to need more than just simple work. Keep your eye on what it will really take to bring them up to snuff and then start comparing that to an aftermarket head. You'll likely find the aftermarket options more attractive than you think.

400 HP at the crank is going to be a real stretch.

Mike I maybe missing something here but going to a 1.6 rocker ratio does not change your static compression or dynamic compression because it does not change youur seat timing events, It does add more duration at.050 .100 .150 ETC. and does add valve acceleration and lift.

That is a big cam for that build.

 

[Photoman]

Post up from the dead...LOL

Long duration cams and tunnel rams will kill your lower rpm throttle response.

I would keep the lift below .470" on a hydraulic flat tappet camshaft for long term reliability.

Use a lower LSA cam for rougher idle.

Keep the duration below 225 @ .050" with the tunnel ram.

Use a split pattern cam with those heads.

 

[Brucer]

going to run the comp cams mutha thumper or a voodoo cam

this is comp cams spec.
operating range 2200-6100 advertised dur. int/.287 ex.305 @.050 int. 235 ex. 249.
lift w/1.5 rockers int .489/ex.476 lobe sep. 107

 

[Photoman]

Call Comp and talk to them about that selection. I think they'll try to talk you into something else.

 

[Photoman]

Hey Brucer...

I took a look at those Thumpr cams. If you must, go with the 12-600-4. Even then, I'm afraid you'll not like it. It'll have darn little vacuum at idle and, with a tunnel ram, will be a real dog at the rpms you're likely to see cruising around town.

 

[RocknT]

I have that Mutha Thumper in my 351W ,,Man it sounds cool but it is dead under 2000 rpm.but it definitely has the Thumpity sound,,LOL I have a video in my gallery of it at idle,, but when it hits 2500 rpm it really comes alive..I still have a stock converter and will be changing that out SOON !

 

[Brucer]

i was going to run a 2500 stall in a 700r4 with the mutha thumpr..

might drop down to the thumpr cam, then again i might just go ahead and bite the bullet and go to a roller cam, and fuel injection.. for the fuel mileage..

thinking maybe the 268xfi-hr13 and a 2000rpm converter and 3.90 gears..

i'm running manual disk brakes...