What type of fluid does NHRA use
 

to check combustion chamber cc's? I have a set of questionable heads and have cc'd them with isopropol alcohol and food color, Everclear and food color, a mixture of RV antifreeze and distilled water, just enough antifreeze for color and parts washer solvent. I know they won't use the Everclear, but I want to use what NHRA uses.

Re: What type of fluid does NHRA use
 

I believe they use Alcohol. It's cheap and does not have a miniscus like water.

Re: What type of fluid does NHRA use
 

In the past, NHRA has used 90% isopropyl alcohol and food dye in a pyrex graduated burette. You would have to check with a current teardown participant to verify they haven't changed that. The reading should be taken at the bottom of the meniscus. I've seen some pretty desperate measures in the barn trying to pass a close combustion chamber. Wire brushing, ice (more than one or two times) , asking to use the racers own burette or plexiglass plate (yeah right!!) leaking valves, and some other attempts that were an insult to the teardown crew's intelligence. Volumes are always best checked and corrected before a trip to the barn. I've seen a spark plug change make a legal head check illegal. A ½ to one cc's worth of cushion at room temperature will save disappointment and embarrassment. Port runner volume is a whole other conundrum but forethought and checking can prevent a surprise.

Re: What type of fluid does NHRA use
 

Don't use the cheap plastic burette... they are all over the place. I had a local guy back checking me with one and raising HE** because I made the CC's way to large.. I knew how close to the spec I had done his heads....so I told him to bring his cheap plastic Burette to the shop.
Took mine (tool room calibrated by USGovt) and poured 100 CC out of it into his.
Sure it was off a whoping 2.7 cc's. He sent that one back and bought another that was off 3.2 CC's He just left it at the shop and doesn't back check what I do any more. If your buddies with any NHRA Teck guys just ask them to check yours... The guys I know in Div 4 were glad to do that..

Re: What type of fluid does NHRA use
 

Thanks all. I use an old glass Pyrex burette. I've since sent the heads to 2 other reputable shops and we all came up with the same senario. My supplied factory heads are illegal. Now, I just have to make them work. Rocker arms are next. I bought an additional 40 intake and 40 exhaust rocker arms for the mix and match and hopefully find the correct stock rocker's for the correct stock ratio with a custom ground camshaft and you all know how long that could take... lobe by lobe

Re: What type of fluid does NHRA use
 

Sounds like you might have found a good excuse to use the Everclear although not as a measuring liquid. (lol) Good Luck....

Re: What type of fluid does NHRA use
 

With our old style hemi we used to grind the tip of the valve to adjust cam lift.

Re: What type of fluid does NHRA use
 

Thanks Art, I'm on it.