The Cal-look Lounge

Cal-look/High Performance => Technical stuff => Topic started by: flatfire on February 20, 2018, 19:18:05 pm



Title: 48 idas, head scratching moments
Post by: flatfire on February 20, 2018, 19:18:05 pm
 Installed my stroker motor last year. Ever since I have had loads of hassle trying to get the beast to idle.
Fuel pressure checked 3 psi. Valve clearances checked. Plugs cleaned gaps checked several times. Changed ignition system.
Along with float setting checked several times with vernier calipers. Tried a combination of idle jets. 55, 60, 65 and 70.
It would still not idle below 1100rpm.
Today in a moment of desperation I looked at the idle orifice, I knew the angle of the orifice should clear the gasket between the carb and the manifold.
Anyway I cut a small segment in the gasket below the orifice and the engine runs at 850 rpm and sounds great. Very happy.  :)


Title: Re: 48 idas, head scratching moments
Post by: dth on February 20, 2018, 19:51:58 pm
Good to hear Peter :)


Title: Re: 48 idas, head scratching moments
Post by: Andrew on February 20, 2018, 19:59:52 pm
That's useful info, thank for sharing, Peter

Andrew


Title: Re: 48 idas, head scratching moments
Post by: j-dub on February 23, 2018, 04:37:27 am
Just to clarify you mean this correct? Only running DRLAs I have never considered this problem. It looks like that orifice is in a notch to attempt to avoid this very issue. Great solution to the problem!

(http://www.timsroadster.com/assets/images/hh031annotated.jpg)


Title: Re: 48 idas, head scratching moments
Post by: flatfire on February 23, 2018, 13:34:56 pm
Yes that orifice. I put a very small drill bit in the hole just to measure the angle it looked like it would pass past the manifold okay. It was just the squeeze on the gasket caused a raised section where the gasket hadn't been clamped down plus maybe a bit of petrol sitting may have caused swelling. Starts of the button and ticks over real nice.