Yes I have searched all over and I don't know what needs to be done to clear a .480 lift cam. Idk what that would cost either, so maybe some guesses? Thanks these are going on my 400 sbc.
I'm pretty certain the ID is reduced for the smaller valvestem diameter, it is on all aftermarket 8mm retainers I can find, AND it is on the stock LS retainers. You could assemble it with 11/32 locks and incorrect retainers, it would just drastically reduce your installed height.cobalt327 said:I'm guessing "89" is the cost.
My take on the retainers is that, yes- they are used w/8mm valves. But as long as the ID of the retainer (where the locks sit) is the same as the retainer for the 11/32" valve (we know they're both 7º), the retainers will work fine- provided you use the 11/32" locks and not try to use the 8mm locks.
This question also came up in THIS thread, although it was never really answered. But if my theory isn't correct, Spin would have surely dropped valves by now- provided that he has actually run this engine.
So your installed height with the 8mm locks and retainers was 1.600" Or is that 11/32 locks and 8mm retainers? Comp makes the proper retainer to run those beehive springs on a 11/32 valve stem with 11/32 locks, its like $65 a set for the retainers though. the tool to cut the guides down for better seals and reduced height is only $50, I bought one and have used it several times. A tap set can be picked up at Harbor Freight for like $20 (cheap but it works). Then you only have to buy shoulderless screw in studs and a Z28 spring kit to run a mild flat tappet cam with no worries. I've done that routine on a BUNCH of heads (usually i use better springs though) and it works great for a mild street engine.spinn said:Summit makes a number of headers, coatings , etc. Clearing up, that these are the basic $89 buck headers for a 85 gm truck.
The inside retainer dia must be the same from votx retainer to v6 retainer, or work with the v6 locks. There might be an extra retainer somewhere, if found the measurements will be posted. The seal part number is not on the reciept, but will post that when it comes to light.
For posterity my crap measurements are saved. My spring measurements could not be repeated every time. My tools are junk.
free length 1.94"
Installed at 1.8 they were about 95lb seat and open 275 at .500
Installed at 1.6 it was 125 and 305
To clear up , the safe running lift is not 1/2" , the seal is going to touch. Lifts of .450-.460" cleared on votex heads with seals.
This would be a 360 lb/in rate.spinn said:Installed at 1.8 they were about 95lb seat and open 275 at .500
Installed at 1.6 it was 125 and 305
I'm pretty sure its 1.800".cobalt327 said:This would be a 360 lb/in rate.
This is very close to the Comp Cams spring p/n 26981. Seat 110# @1.7", open 292# @ 1.175 (0.525").
My question is why would GM this spring on the 3100? Maybe it's because of the redline of this engine. Or a tall installed height... Anyone know what the installed height is on the 3100? Or the redline? I know the redline of the '09 Impala 3.5L is 6400 and will rev higher.
Your spring seat remains unchanged, unless you want to sink it slightly. You only cut the guide in height and in OD to prevent retainer to seal clearance, AND allow the use of .530 valve seals, which come in MANY varieties for dirt cheap.spinn said:Is sinking the spring seat the good way?