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SBC 383. Blow by

General engine tech -- Drag Racing to Circle Track

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73c34me
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Re: SBC 383. Blow by

Post by 73c34me »

Aluminum heads. I ran 93/94 octane with a boost, 180-190 coolant temps and did not lug the engine. Perhaps that compression ratio can’t be done. Track time would have had race gas.

I will start with a camera inspection and see if I can borrow a decent leakdown tester.
F-BIRD'88
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Re: SBC 383. Blow by

Post by F-BIRD'88 »

A compression ratio of 10.5:1 will be a lot more reliable on your 93/94 pump fuel. There is no free lunch.
73c34me
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Re: SBC 383. Blow by

Post by 73c34me »

Update. I drove the car approximately 100 miles the other day. No changes from before, which facilitated my original post. I drained the catch can after the drive. I got about a teaspoon of oil. I could not see tail pipe smoke, but am sure there would be some. My original post- i drained nearly a cup of oil from the catch can after a 125 mile drive, so a big reduction. I have ordered an oil analysis kit and will use a bore scope soon. But currently- the car runs really strong and good...
C.A.R.E.
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Re: SBC 383. Blow by

Post by C.A.R.E. »

While you inspecting things with the Bore scope check the pushrod relief in the heads. When the last head work was done it may have been ported to thin and be cracked from the port to the pushrod relief. It'll pull oil thru the crack. Especially high vacuum ( idle & coasting with the throttle closed. ASK Me how I know !
73c34me
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Re: SBC 383. Blow by

Post by 73c34me »

Good advice! I have wondered if i am pulling oil from a crack. A couple areas were getting a little thin during the porting phase... the porter was stubborn! I am the guilty party.
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