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Discussion Starter · #1 ·
Team,
I do not have any fancy equipment to check lift or valve seal to retainer clearance. I am putting in a new Comp XE262. See the specs below. I have been told this is right on the edge of what a stock set of vortecs can handel without any mods. My heads are stripped bare currently. My friend is telling me to install the cam and drop in the lifters. He has some very weak springs we can put into the heads. He then wants to bolt the heads up without a gasket. He claims if we can turn the motor over and nothing binds up we should be fine because the extra .039 thickness of the headgasket is insurance. Is this a good idea? Is this really enough insurance? I know many of you would take it to a professional shop, but that really isn't in my budget.
CAMSHAFT SPECIFICATIONS:
Small Block Chevy 262-400 Hydraulic Camshaft
APPLICATIONCAMSHAFTS
VALVE SETTING
RPM
OPERATING
RANGE
CAMSHAFT PART NUMBER
CAM GRIND NUMBER​
DURATION
VALVE LIFT @ 1.5:1
LOBE SEP. ANGLE
ADV.
@ .050”
IN.EX.IN.EX.IN.EX.IN.EX.HYDRAULIC FLAT TAPPET: Excellent response, good mid-range, noticeable idle.
Hyd
Hyd
1300-5600
12-238-2
XE262H
262
270
218
224
.462
.469
110°​
 

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I'll leave the clearence part to the experts, but I'd advise to get some new springs. Although the cam isn't a monster, it's still a performance cam. You have good heads and a good cam, don't slap it together with weak valve springs only to be disappointed with it's performance, JMHO.
 

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He then wants to bolt the heads up without a gasket. He claims if we can turn the motor over and nothing binds up we should be fine because the extra .039 thickness of the headgasket is insurance. Is this a good idea? Is this really enough insurance?
Are you concerned with piston to valve clearance as that's what the above will check?
Your borderline with the retainer to guide clearance and that I'd get checked as the above check doesn't account for a running engine..
 

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Discussion Starter · #4 ·
I did get good new springs. I actually bought a complete comp kit with chains and everything. I am worried about the retainer to guide clearance not piston clearances.
Basically do you guys think this test works as a retainer to guide clearance check? If I clear without the gasket (basically adding an extra .039 travel in the pushrod movement). Should I be ok with a running motor with the gasket installed? I know there is extra movement you can not account for simply by turning the motor by hand. Is .039 enough to account with?
Is this question confusing enough?
 

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Take an intake and exhaust valve and put them in to the head. Install a valve seal you are going to use. Put the retainer and locks on the valve and pull up on them. This should grip them to the valve. Now with the valve in contact with the seat in the head measure from the top of the seal to the bottom of the retainers closest to the valve stem and seal. The area between this is the maximum cam lift that can be use for the assembly.

Now this doesn't tell all. You now need to find out what the coil bind is on the spring. ...coils stacked...then subtract this number from the installed height along with .060" to .100" more to give you clearance before coil bind. This will give you max cam lift for the spring assembly and clearance before coil bind..
 

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Take an intake and exhaust valve and put them in to the head. Install a valve seal you are going to use. Put the retainer and locks on the valve and pull up on them. This should grip them to the valve. Now with the valve in contact with the seat in the head measure from the top of the seal to the bottom of the retainers closest to the valve stem and seal. The area between this is the maximum cam lift that can be use for the assembly.

Now this doesn't tell all. You now need to find out what the coil bind is on the spring. ...coils stacked...then subtract this number from the installed height. This will give you max cam lift for the spring assembly.
Not a good idea to run the spring at full stack. I would not run any closer then .050 from full stack.

Tom
 

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Not a good idea to run the spring at full stack. I would not run any closer then .050 from full stack.

Tom
Tom,
Did not mean run the spring to coil bind just calculate it so max lift along with clearance could be figured. I will edit my post to state this. Thanks
 

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It's actually a pretty simple deal, if you think about the parts a bit and look at them. Not hard to understand.

The problem with the Vortec heads and clearance, is that the valve guide is HUGE. It's real tall and also real big around. So tall, that the retainers will hit the seal at a lift of somewhere in the range of .465" and .480", depending on the production tolerances of the particular castings and parts you have. So big around, that the ONLY spring types that can be used, are singles without a damper; a damper won't even fit around it, it's so big. This SEVERELY limits the cam properties that can be used without machine work.

What you need to do is to first, dummy up the retainers and keepers on a few valves on each head with some real light "check springs" (you can go to the hardware store and get some little spsrings that will work just fine for that), with the seals installed; and measure how far the valve can open before the bottom of the retainer smacks into the top of the seal. You need whatever the cam's "spec" valve lift is for the cam you want to use (which BTW, the XE262 is a good choice), PLUS AT LEAST .050" or so.

The guide OD is so big that you can ONLY use a single spring. You DO NOT want, under any circumstances, to leave the stock springs on there. They are total crap. Typical garbage stock springs. You could use a Comp 981 and pull the damper out of it, or Crane sells a spring that's roughly the same as the 981 that you can buy also without the damper although I don't know if it would be any cheaper to do that. Another option would be to use the "beehive" springs; they don't need a damper, and their retainer is smaller, which automatically gives more clearance.

The last option would be to machine the guides down. But that costs money; and the "economy" of using those heads goes away IN A HURRY when you start doing machine work to them. It's real easy to end up with 80% or more of aftermarket money tied up in them, and still have just a pair of junk stock heads. I'd advise trying to work within their limitations, rather than trying to overcome them, for this reason; not so much for technical reasons, but purely for "value" concerns. If you're going to end up spending aftermarket money anyway, might as well spend it on aftermarket heads.

Probably the cheapest way to get what you need is to buy the kit from Comp that has the cam, lifters, timing set, springs, retainer, keepers, and seal, all in one package; then take the dampers out of the springs. If your retainer-to-guide clearance is too close, you can use a file or a die grinder to take a little bit off the top of the guides. DO NOT grind on the retainers, unless you're willing to risk one failing and dropping a valve.
 

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take the heads to a machine shop and have the guide boss machined down. my machine shop said $25 last time I asked. They have a cutter than machines the guide boss t a smaller OD and shortens it. This will allow you to run a PC type sealand also run like a Z28 style spring and any cam that will work with the springs you choose. There is a ton of info on this mod on the net.
 

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Check out this thread on Vortecs
http://www.nastyz28.com/forum/showthread.php?t=56505
Read the first couple pages that is where all the good info is.

You have to measure your heads as mentioned above to see where your at. You want to have .050" retainer to guide clearance in the end. My vortecs R-G was .480, add .050 and that's .530 subtract your .469 and that leaves you .061" that you need to add(remove) for proper clearance. There are a couple ways to do it, beehive springs, have the heads machined, etc.

The test procedure your friend is offering will not help you with this, he is checking valve to piston clearance not valve guide seal to valve spring retainer clearance.

Many people have done grinding on the retainers without failure, it is a risk you have to weigh, but if you use LT1 springs retainers there is a lot of material there to work with and the max you want to remove is .090"
HTH
 

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Discussion Starter · #12 ·

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Just for some more info.
I've already ponied for the vortecs (with new intake and valve covers for 450 shipped to me). I've already bought the comp cam kit. This is the exact kit I bought.
http://cgi.ebay.com/ebaymotors/ws/e...0039678989&category0=&fvi=1&item=360039678989
It does have the dampner in there. Does everything think it is acceptable to pull the dampner out of the middle?

The dampener onlt stablizes the spring. If you don`t machine the guides, they will do a similar job. Since they are bare already I would`nt chance it. Check with your machine shop and ask how much it will cost to machine the guides down so that you have plenty of clearance and you can use your sprngs with the dampenr they came with. Like I said, my machine shop said $25. Thats cheap enough and you won`t have to wonder if you have enough clearance.
 

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Ya I wish I had a local machine shop. I live in Peoria Illinois and I haven't lived here long enough to even know where a machine shop is at, yet alone one I can trust. That is why I try to do it all myself.

Well then you can buy the cutter and do it yourself with a drill . Comp makes the cutter which you can get from Summit. There was a guy on nastyz28.com that was selling them for $60 and one guy was renting them out I think. If you cut the bosses you`ll eliminate any question that you have enough room and it will alolow for more cam in the future. The cam you picked oput will work great with the vortecs though.
 

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Discussion Starter · #17 ·
Another question into the mix here. I started this thread too.
http://www.chevelles.com/forums/showthread.php?p=1833330#post1833330
It is asking about the positive type valve seals that were on the vortecs I bought. Comp supplied me with the simple O rings that go on the retainers. Is the O ring route good enough or am I asking for problems? I would think the O ring route is good for me because this is the area I have clearance issues with already.......... correct?
 

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Another question into the mix here. I started this thread too.
http://www.chevelles.com/forums/showthread.php?p=1833330#post1833330
It is asking about the positive type valve seals that were on the vortecs I bought. Comp supplied me with the simple O rings that go on the retainers. Is the O ring route good enough or am I asking for problems? I would think the O ring route is good for me because this is the area I have clearance issues with already.......... correct?
=
Forget the O rings, they will not work with your setup. ;)
 

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It's very easy to cut the guide down on the vortecs. The comp guide cutting tool is quick and easy to use. You can then run the .530" valve seals. Summit sells the tool on Ebay for 43.95 plus 10.00 shipping. Get the seals from them also and you won't have anymore worries, Except measuring installed height and what shims you'll need. Those springs go installed at 1.7"

http://cgi.ebay.com/ebaymotors/Comp-Cams-4726-Valve-Guide-Cutting-ToolCarbide-Tipped_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247QQcategoryZ33614QQihZ012QQitemZ220230743768QQrdZ1QQsspagenameZWD1V
http://cgi.ebay.com/ebaymotors/Comp-Cams-503-16-Valve-Stem-Seals-Teflon-Positive-Stop_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33621QQihZ012QQitemZ220233532436QQtcZphoto
 
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