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******* CC checking

2K views 17 replies 7 participants last post by  dave350v8 
#1 ·
So out of curiosity and not willing to spend money. I used the ******* CC check on my LT1 heads I did a while back. I was hoping for about 190cc and saying 10 percent is error I'm sure were in the ballpark of 190cc. I was just surprised it all pored in honestly.

What do you guys think 190?
 

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#4 ·
Wine/beer making suppliers have 100ml graduated cylinders for cheap, drill a hole in the bottom and press in a plastic hose barb (a drop of crazy glue will seal it) and then attach hose and an aquarium ball valve to the end to control flow at the port cover. I use food coloring to tint plain 70% rubbing alchohol for measurement.

Voila, ******* burette...accuracy to 1cc and the alchohol evaporates quickly so no mess.
 
#5 ·
Thanks for all the ideas everyone. I'm going to look for a used slab of plexiglass and drill a hole in it. And then look at a better ML delivery device.

Also I got bored and ported the roof more till I could see the rocker stud holes. Need to fill that with epoxy. Better get the heads pressure tested at this point.
 

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#7 ·
Plugging the holes you exposed has no positive effect on flow, just seal the rocker arm studs before install.

Bowl and short side radius is where the power is, as long as the long side is smooth don't waste your time.
 
#8 · (Edited)
I dropped one off to get pressure checked they said the same thing about the holes.

I first experimented with porting on them back in 1999 when I had no clue what I was doing. I got lucky I did not punch through the exhaust when I did a no no ( Ported the floor of the exhaust ) I remember when I took it to the shop I was all excited to show off my work and they said " You $%ed them up " LOL

I only decided to rebuild it for the 3rd and final time because its a rusty trusty ( We got history ). As jacked up the LT1 Frankenstein build is she still ran surprisingly well.
 
#12 ·
LOL Yea I know its darn bad on that side.

I often wonder how much HP it is loosing over that 15 year old mistake. It needs all the help it can get on the intake side.

I have a picture somewhere of the first intake porting that should be good for a laugh also.
 
#13 ·
your exhaust might not be that bad- I wouldn't lower the floor intentionally but if you have good taper and did what you could with the short side you may be better than you think.

Also, to break surface tension- some simple soap will "get er done".

BTW, "cc's" are essentially meaningless, what you should be concerned with is dimensions, not volumes. If you ASSUME you have a good port layout and taper then 190cc's is ideal for a 350 hitting just over 6000 rpm, BUT that can be a lot to assume when you're porting a stock head. What is your valve size and CSA at the pushrod?
 
#14 ·
AP72,

I went back to the machine shop today and was looking at some 80's and 70's exhaust and your right about the port. Its still raised more than a early race heads and its blended higher with less a turn at the top.

The CSA is 1 1/8" I use a ******* tool to make sure its close on the intake side picture attached.

And the valves are 2.02 1.6 with bigger seats installed.
 

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#15 ·
the CSA is an area, not a length, but I assume you mean 1.125" in each direction. I use a cut piece of wood for my minimum areas to check it and gauge it off of that- not pretty but it works in a pinch and I don't have to make it perfect for a paycheck.
 
#17 ·
Oops my bad looked at it again on the PC smartphone can cause communication errors on a small screen.

I use my ******* tool to measure the pushrod pinch width when blending back in the intake. Its like a free snap tool.

That's what I was trying to communicate in the previous message.
 
#18 ·
Thanks everyone for your input, seems quite a common problem with aftermarket heads, thanks for not knocking me for buying Chinese...

And yes the photo link that was posted for me is exactly the same witness marks on the valve stem, lash caps seem a good idea to spread the load, do find it hard to believe that being 80 percent contact area on stem would cause so much side load creating rapid guide wear!!

Thanks again
cheers
 
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