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200 psi cold cranking
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Author:  skitzone [ Sat Feb 25, 2017 12:53 am ]
Post subject:  200 psi cold cranking

Stock recon series 2 bluebird with a 280 degree cam can didnt come with a dial in card and regrinders told me to time it to standard. Going to read up on how to use a dial gauge to check the timing tomorrow. I've tried it at the standard #2 timing and retarding down to #1 . I've always been told 180-190 psi is max on pump fuel. The cams ran in runs nice all the lash has been double checked. Is 200 an OK cold cranking on Datsuns or is it way to advanced?

Author:  yellow1600 [ Sat Mar 04, 2017 5:57 am ]
Post subject:  Re: 200 psi cold cranking

My l18 has about 205psi cold cranking pressure. It runs fine on 98 pump fuel. Just remember that cranking pressure is not compression and has more to do with camshaft specs and cam timing and is more like a tool to check the health of your engine.

Author:  skitzone [ Sat Mar 11, 2017 4:50 am ]
Post subject:  Re: 200 psi cold cranking

Car runs well i'm on holiday i got it driving the night before I flew out. I ended up retarding the cam timing to #1 specs to see if it'd calm it down a bit. I understand that the dynamic compression isn't to do with the static and opening timing and closing of valves has a big part to do with it. I was just a bit worried as I lost two ringlands running a pontiac cam in as the 205psi in the chambers caused it to hydro lock 30 seconds in the shaft was too small for the compression. Went from 6,000 mile old recon with 158-165psi across all 8 with a blown head gasket to 205,205,204,102,205,205,205,96 ever since then I've been super cautious about to much cold cranking pressure. All the books said it'd be fine but i guess leaded fuel specs vs new school fuel it wasn't. In the iron head v8 world on pump gas 180-190 is you're reliable limits and didn't know what was okay with a cast alloy head.

Possibly one day I'll get the dial gauge out and measure all the lifts to see how close it is to straight up but cam didn't come with a card and with the larger duration and higher lift the cranking should have come down not gone up. I think it also might be time to upgrade to a snap on tester as this one was around 190 after four strokes but would max out at 198-202 unsure if the valves completely sealing it might be adding to the number with each stroke.

But yeah long story short seems to be a very healthy little l20b.

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