You are "good", with the overlap event showing cam advance at lash.
Based on your test numbers, the engine will have lots of low and mid range power.
DD

Excellent, thank you for all the support Doug!

last month, I originally assembled this motor with 8:1 compression and a stock "builder" cam that was too retarded. Car ran great but could not get out of it's own way. I should have this all back together by next weekend. With compression increased to 9.3:1 and a properly indexed RV cam, I'm hopeful I'll find the power I was missing. I'll share my "seat of the pants" experience in the weeks to follow.

thanks again everyone. -shane

Based on your numbers, this build will have way more "spunk".
You will have to listen closely for spark knock, 9.3 static CR with that 'small' cam, has the DCR up in the 8.5 range, that's a bit steep for pump gas.
If the enging knocks a lot, tighten-up on the intake lash and recurve the distributer to adjust.
DD

I was targeting 9:1 compression but when I re-measured the head after machining, I'm well into 9.3:1. I recognize the need to tune-in the distributor curve to support all of the changes but should I also consider a thicker head gasket to get me closer to my original 9:1 target? This car probably won't see the bulk of my driving miles, would 91 octane help support the 8.5 DCR?

thanks, -shane

You might be a candidate for a larger cam.....if you have the gears for it.

Im pretty sure you will need premium fuel.

You will need to do a curve.

My care with a DCR of 8.3 can run on midgrade but I have a 5 speed and low gears.

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

I would go for either longer duration cam or thicker head gasket.

Lou

_________________
Home of Slant6-powered fun machines since 1988

Thanks, it sounds like I have options.

I'm going to stick with the cam. I'll get it on the road and see if tuning and decent gas will get it done. If in the end I need to lower the compression, than a thicker head gasket seems the easiest.

For grins, I searched this site for gasket options. My measurements are based on the standard .040" Fel-Pro gasket. The only options I could find for varying thicknesses are custom copper gaskets. I'm not eager to put a copper gasket on a street driven car. Does anyone make a thicker OEM style gasket?

Cheapest/easiest is a bigger cam.....DCR around 8

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

You might be right. I have to admit, I'm reluctant to buy another cam - just bought this one. I wanted to stay with my single carter, it works well. I considered the RV-15 cam but it is recommended for two barrel carbs.

Felpro gasket is about 0.034" installed. Permaseal and ACL gaskets, and many others, are around 0.046".

Lou

_________________
Home of Slant6-powered fun machines since 1988

Lou, Thanks for the thick gasket pointers.

Considering that my CR is a little high for my cam profile, I decided to scrutinize my CR calculations to insure I knew exactly where I was. Specifically, I started over thinking the deck height measurements and found that there is a measureable (and favorable in my case) difference in how it's measured. I started a new thread focussing on what I'm seeing:

http://slantsix.org/forum/viewtopic.php?t=43886

thanks -shane

I've had it running for over a week now. Car is pulling well up my steep hills. While my previous cam was of an unknown grind, I suspect the proper alignment of the new RV-10 cam has more to do with my power gains than the grind itself. I'll never install a cam or timing chain again without degreeing it in - lesson learned.

I've only managed to rack up about 100 miles on this rebuild so far. It's been raining pretty steady here in northern CA, not friendly convertible weather.

I'm currently running 91 octane, haven't yet looked at my mechanical advance yet but happy to report that I'm not having any detonation issues. I expect to find a little more power when I dial-in the distributor curve. Should be a fun Spring project.

thanks again for all the help everyone! -shane

Sounds great, Shane. Enjoy the ride...

Lou

_________________
Home of Slant6-powered fun machines since 1988