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PAC Racing Valve Spring Height Gages |
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PROSTOCKTOM
Supporter of TheAMCForum Joined: Jun/20/2010 Location: Indiana Status: Offline Points: 2450 |
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Posted: May/23/2020 at 2:15am |
So I had some stimulus
money burning a hole in my pocket and I decided to buy myself a super fine PAC Racing
installed valve height gage. Before I start I’ll show a photo of them I took in
ascending order from left to right part numbers, PAC-T901, PAC-T902, PAC-T903,
and PAC-T904 I am currently working on a set of 440 heads and the springs I am using have an installed height is 1.85" which is a lot shorter than I am used to using, so I look at the PAC listing and I see. "PAC-T904 Installed Height Gauge - LS & Duals 1.400-2.000 Range Purple" Great that looks like the one I need because I am using K-Motion K800 dual valve springs. Right? WRONG!!! The hole in the top of the gage is only .995” and my Comp Cams 1730 retainer has a 1.065” step, so this isn’t going to work at all. Time to send it back right? Nope So after this tool sits around growing on me for a few hours I reason that, Well I'll just keep it and use it on a single spring retainer if I ever need it and start looking for the one I need. So here we go again!! I look at the chart again and I see, "PAC-T902 Installed Height Gauge
- Pro Series & Drag Race 1.800-2.600 Range Red" Alright this one will do
the trick since I am not normally playing with a spring with an installed
height of less than 1.800" anyway. So I order this one and I am all happy.
Then later in the afternoon that day it hits me that I have made a big mistake
because I forgot to account that while the gage will technically adjust to 1.800 it will not fit the range I need because you have to crank it below your
installed height by at least .200"-.250" to have room to get the valve
keepers in the retainer depending on your valve and retainer combinations. This means I need around 1.600" before it will work. Screwed up again!!! At this point I hate
to admit how much money I already have spent for something I
really didn’t need in the first place, but wanted so onward we go. Now I am only left with two other options at this point and after looking at the PAC chart again I know the T-904 is for Beehive
retainers, so that one would be really small so I order, “PAC-T903 Installed Height Gauge –Engine Builders
1.400-1.900 Range Orange”. Boys and Girls we have a winner here. The old
saying, “Third time is the charm” never rang truer. Had PAC even bothered to
have any dimensions at all on their website I could have just bought this one
from the start it would have saved me a whole lot of time and money. I always
tell people education cost. How much are you willing to learn? Well I am now an
expert on PAC installed height gages and I paid the price to learn all about
them. I will note that the T-902 and the T-903 both
have a 1.195” second step diameter and a .950” third step diameter. At this stage I now have three of them
sitting on my desk and being the kind of guy that likes complete sets of tools I
thought, you’ve already spent a fortune why not and go for it and went ahead and ordered the
last one, “PAC-T904 Installed Height
Gauge- Beehive 1.400-2.000 Range Blue” and completed the set. Note this one
has a second step i.d. hole of .755”. Hopefully this review will educate anyone
that might be thinking of buying a height gage and really has no experience
with them. I’ve been using telescopic bore mic or vernier calipers for
years to do this job and those have served me well, but just wanted an easier
and more accurate way of doing the job without the previous efforts I've used in the past. Also note that PAC calls them a Gauge. It was always my
understanding that a gauge has a see thru face with a dial, which really mean they should be called gage/s. Either way if you want probably
the finest made gage buy a PAC. They are American made in Michigan from
440C stainless steel, beautiful anodized sleeves with finely cut markings. I checked two different heights with a Starrett 226 inspection grade micrometer and the adjustments are within .002" which is more than adequate tolerances for my needs on a valve spring. Tom
Edited by PROSTOCKTOM - Jul/12/2020 at 6:43am |
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amcenthusiast
AMC Addicted Joined: Jul/02/2012 Location: SW Atlanta GA Status: Offline Points: 1778 |
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Cool valve springs and cool tools... Next thing would be to have valve spring kit specific install height tool with approximate lbs rating at that particular height... where the tool shows the estimated spring pressure of that particular spring at every setting? -an educational tool, or so the installer doesn't have to do any math, to translate the 1.9 lbs rating into spring rating @ 1.85" etc? |
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WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5798 |
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I could have used one of these recently, sounds like I avoided some hassles, but now have a guide to work with for next time.
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I've finally given up drinking for good...........now I only drink for evil.
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