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Topic: Flexplate and Damper, Install 383 TPI engine

in Forum: C3 Engines

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Flexplate and Damper, Install 383 TPI engine (1/3)
4/28/07 5:19am

gu81

Lifetime Member
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, - Japan

Vette(s):
1981 Coupe, Daytona Yellow w/700R4 AT, 383ci ZZ4+TPI Mod.Motor, Haltech E6X computer full controled, Rack&Pinion Kit, Front leaf spring kit, SSBC Alminium Brake Calipers, Recaro seats, Momo steering, Autometers, APEX Digital Meter, etc....

Joined: 2/4/2006
Posts: 2

I own 1981 coupe with mod. TPI L98 and TH700R4. But the engine lost the compression.I'd like to install another 383 GM engine to my C3. I bought this used engine from my friend.

I have only following informations of this motor:-SBC one-piece rear main seal, 4 bolt mains block-3.750" 4340 crankshaft, internal balanced-6.000" 4340 H beam conrod-SRP flat top 4.030" forged pistons, 10.7-GM performance FAST BURN Cylinderheads #12464298-EDELBROCK HIGH-FLO T.P.I. VORTEC BASEPLATE #3817-COMP CAMS Nitrous HP NX288HR Cam, Hydraulic Roller Tappet, Advertised Duration 288/ 315, Lift .520/ .540 #08-303-8-hydraulic valve lifters 214B

And...

-B&M flexplate, externally balanced SB V8 with 153 tooth ring gear & 10-3/4" b.c., #20238

-7" SFI 18.1 harmonic balancer, #A325561?, I'm not sure it is balanced Ext. or Int.

Pic 1

Pic 2

And so I have some questions.

May I use this B&M externally balanced flexplate and harmonic balancer?

Should I check this harmonic balancer's spec?

Or may as well install my L98's stock flexplate and harmonic balancer?

I asked some car shops these questions. But each differs.

I'm so confused cos' I'm not a mechanical engineer.

It's my amateurish idea, I'm afraid of vibration of the Ext. balanced flexplate.

Any help would be greatly appreciated. Thanks.

(Large images modified to links) gu812007-04-28 20:17:40

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Flexplate and Damper, Install 383 TPI engine (2/3)
4/28/07 2:44pm

Adams' Apple

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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 20170

I believe most 383 engines use 400 balancers, and flywheels(flexplate). But, if your engine is internally balanced, you may not want to use the 400 stuff, as it(the 400) is external balance.
Maybe one of the other engine gurus can answer this one...?
Since you have the part #s of the flywheel and balancer, maybe you can contact B&M and see what they have to offer as far as advice.

______________

Joel Adams
C3VR Lifetime Member #56
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(click for Texas-sized view!) NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

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Flexplate and Damper, Install 383 TPI engine (3/3)
4/29/07 10:21am

gu81

Thank you very much for the quick response.

I think simply, I should choose the neutral balanced dampers and flexplates for the internally balanced engines. I have to learn more about the engines. Confused

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