Thread: 383 build-Something Caught My Eye

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the stock gm roller stuff is fine built many. the marine stuff used most gm lifters and will see the same rpm you will ever see . buy new gm roller lifters they last for many miles .for the cc runner from 170 to 180 i would of liked to see the 170 heads but real dyno numbers would be the acid test

Pat, I don't mean to get in anybody's way here, I just want to help.
Gary, I just went back and re-read the entire thread. I'd use the 12410 heads. With your 18cc pistons, in the hole 0.010" and a 0.040" gasket, you'll be at 9.4:1 static compression ratio. The 12410's have bronze guides, 64cc chambers, 2.02"/1.60" valves, +0.100" long. I might order the heads bare from Competition Products along with the valves, springs (part number on the timing card linked here), etc. and have Pat put 'em together.
650 carb on an RPM intake, 1 3/4" long-tube headers, H-pipe right after collectors.
12 degrees spark timing at the crank, 22 degrees at the weights for a total of 34, all in by 3000. I see no need for a double-throwdown super-over-and-under distributor. A well-built HEI (shimmed at the drive gear) should do it. Use a Crane adjustable vacuum can. Coordinate the dizzy drive gear with the cam mfg.
Use CompCams 08-410-8 or equivalent, installed retarded 2 degrees.
08-410-8 - Magnum
RPM HP TQ
1000 63 331
1500 111 388
2000 160 420
2500 202 424
3000 256 448
3500 312 468
4000 360 472
4500 396 463
5000 419 440
5500 395 377
Peak volumetric efficiency 88.7% @4000
Peak BMEP 186.1 @4000
The only thing that bothers me is the full dish on the pistons. I would prefer a D-cup with a nice squish pad, but if Pat says they will work, that's good with me.
The goal here was to build a max torque motor at rpm's useable for towing.
If anyone sees anything on this post that won't work, please holler out.

no thats fine with me tech ..i think the rpm is to hi for max TQ engine were my cam will not make that HP it will make max TQ under 4000 rpm and that will work better for pulling and MPG ?????? the ic735 is a step dish i do not see any thing saying it is a full open dish piston ?? it has some pad

I'm liking alot the 400lbs or more of torque.

480 of tq should be in your reach i was getting that at under 3600 rpm the comp s cam s i did run them as were on the file . i just made more of TQ with a Erson /Mc grind

I think the Scat stroker profiled 4340 I-bean rods w ARP 9740 7/16" capscrews part number SCR5A7,Howards Track Smart 4340 steel crankshaft with Kings bearings should be able to handle that torque rating with room to spare.A over build for long term reliability.Likely going to need the expensive Mallory metal for balancing.What's your opinion??.

Originally Posted by pat mccarthy

480 of tq should be in your reach i was getting that at under 3600 rpm the comp s cam s i did run them as were on the file . i just made more of TQ with a Erson /Mc grind

OK, at least we have a baseline pull to start from on the DynoSim. Tell me what you want now for parts and I'll change 'em out. I'll need either the cam mfg and part no...... or valve lift and timing events if you don't have part no.

i pm you and it did not go threw some thing going on with the form . on the mallory metal No and you do not need the 4340 crank cast is more what you want . with the 4340 you will need to run the H bearings kings are ok but need to be fitted a every street driver cast steel is all you need. your friend can not sink mallory metal ? we can do that job if needed but you should be fine if you stay external bal like the 400 sbc

I got a whaling deal on the Howards.Close to the cost of cast steel.Jim has a shop that they farm out balancing.

OK, installed the 14097395 cam, retarded 4 degrees. Installed standard Performer intake manifold. No other changes.
RPM HP TQ
1000 68 358
1500 116 408
2000 172 452
2500 225 472
3000 264 462
3500 301 451
4000 334 439
4500 352 411
5000 348 366
5500 310 296
Peak BMEP 186.1 @2500

Humm.Given the wheel speed calculator here is what I got.

Engine RPM Calculator

700R4's don't like towing in O/D-so that is 1 to 1 in third.

At peek Hp this is what I got

Engine RPM Calculator

That is towing in third.............105mph pushing what is akin to a pc of plywood down the road.

Not towing in O/D:

Engine RPM Calculator

140 mph Astro van in O/D.

Now with enough courage,no one on the road,and a serious death wish..........I could get to peak hp in O/D.in a Astro that has the aerodynamics of a big box. LOL.


But all kidding aside,the ability to have enough RPM/HP for passing might be something here to look at.It is kind of dis-concerning to see 68hp at 1000 RPM.

Guess what I am asking here is we are making more torque than most if not all 4 cylinder diesel's,but my experience with them is at highway speeds,they are real dogs.Opinions??.

Originally Posted by 1gary

Guess what I am asking here is we are making more torque than most if not all 4 cylinder diesel's,but my experience with them is at highway speeds,they are real dogs.Opinions??.

From the numbers Tech posted, I think you'll have alot of fun.
You should have no issues passing on the highway either.

Don't sweat the 68HP, it means nothing. Torque is king at low speed.
You'll have to feather the loud pedal not to spin the tires taking off.

cam i used was 224/230 480/480 lsa 110 in at 108.. TQ is what gets you rolling from the get go i take TQ over Hp any day to pull we have cams that make over 1000+ tq on a small shot of Nos hard to beat that. thats the seat of your paints feel as you get nailed in the seat with the big engine and bust weak drive train parts

gary clear your pm mail so i can send you your PM