[Stikman33]

Hey guys, i am constantly learning about this car i have been working on for so many months now. I finally tracked down the previous owner who had some engine work done. Apparently the engine was build at a machine shop in Dublin, Ca and has 10:1 compression TRW pistons installed. What octane should i be running? Thanks for the help.

 

[Bob West]

I'm at 10.5-1, I use 93 on the street,and turbo blue at the track,100-110,alot depends on the cam and your timing also.

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Bob West
1972 Malibu
454+
TH350-3.73's
3900 lbs.
1.79 60 ft.
12.06 @ 112.89

 

[BB_Mike]

The motor setup is crucial.

with right at 10:1 you should be fine with 93 octane any where you go.

Be sure the total timing is below 40*BTDC. Most run a 36*, that's a good goal to tune for.

Keep an ear out if you have a car full of friends and are racing up hill.

-Also a don't be too lean on the A/F ratio.

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71' 3880# with me. Big Block 402, Merlin oval heads, 10.2:1CR, TH400, 3.73 posi,
1/8th: 8.0 @ 88mph
BEST 60': 1.85 w/street tires.
BEST 1/4: 12.5 with 1.89 sixty foot (street tires)
BEST MPH: 109mph

Picture of me roasting the tires and other guy stuff
Video of me staging (smoke of course)

 

[Stikman33]

Robert, cam is pretty medium, nothing extremely heavy but you know its there. Timing is 8 degrees advance, not sure of total.

 

[Stikman33]

Hmmm, well, d**m california smog law. The highest octane gas i can get at most pumps is 91 in the bay area. I might have to invest in an octane booster company.

 

[onovakind67]

I run the local 91 octane in my daily driver 406 with 10.4:1 compression. Tight quench height, polished surfaces and 36° total timing have me operating with no detonation.

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67 Nova 3475# daily driver
10:1 406, 700R4, 224° Comp cam, RPM and a Q-jet - 11.76 @ 116
64 Chevelle Road Racer
67 Nova Wagon under construction
65 Corvette Road Racer

 

[Stikman33]

Excellent, thanks for the info guys, that satisfied any doubts or questions that i had.

 

[HOTRODSRJ]

If you go to my technical links site at www.inccn.net/jackstandslinks.htm , you will find several ariticles and/or links to octane issues and compression issues. Too many to list here.

Enjoy...and good luck

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Steve Jack - ConceptOne Pulleys and Brackets / Engineering & Marketing Technologies

[This message has been edited by HOTRODSRJ (edited 03-10-2002).]

 

[DaleM]

I've run everthing from 87 to 93 octane in my 67 BBC w/10.25 compression and a mild cam for close to 14 years now. Never had a problem.

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TC Gold #92/ACES #1709
67 SS & 67 Elky
Dale's Place
Team 67
Midwest Chevelle Regional Governing Council
Integrity: If you have it, it doesn't matter - If you don't have it, it doesn't matter.

 

[Fried_Guy]

Now, what types of heads are these? Fe or Al?

 

[Stikman33]

They are polished and ported camel hump heads. Fe.

 

[Fried_Guy]

Would 10.5:1, with valve relieved pistons, iron heads, and a .040" quench on 91 octane be okay?

I want to lower my quench by buying shim gaskets, and if I do it'll raise my compression quite a bit.