Snafu

iTrader: (1)

I've finally gotten a solid measurement of my P/D height. It came out to be .005" exactly.

My heads are angle-milled with 58cc chambers.

I ran it through a couple calculators and figured my CR will be about 12:1 (11.96 if I recall correctly) with a .035" quench (Cometic MLS 3.910, .040" gasket).

Being that the compression is increased I wanted to keep the quench tight to reduce the chance of detonation...my heads/valves are also coated which should help out there too.

I didn't do a flycut on the pistons.

So what do you guys think?

[Stock bore and stroke, angle-milled heads, 7.35 pushrods, stock rockers]

LS1 Swapper

I'm running tighter quench and bigger chamber size (11.5:1) without a problem. Flogged it hard on the race track(lapping not drag) last weekend without issue. Remember these engines expand(assuming aluminum block) when at operating temps so that quench will loosen up ~0.005" (block expansion less stock rods and pistons expansion)

PTV clearance becomes a bit on an issue when you really tighten it up(especially with milled heads for more compression), what camshaft are you planning on running?

Snafu

iTrader: (1)

Thanks for the input LS1 Swapper...looks like you're the only one who wanted to touch this thread.

The bottom end is all stock, so yeah, the block is aluminum. Heads were sent to FlowTechInduction to be flowed and a custom grind cam made to match. The cam is not too aggressive as it's meant to be a sleeper (220/226 at close to .60" lift int&exh @ 114 LSA).

I know guys running .030" quenches on AFR heads...but I don't think they were milled.

My PTV clearance is my only real concern seeing as my tuner (Jeff Creech) can tune for up to about 12.5:1 on pump gas. Any recommendations on measuring PTV clearance? I know one way is to put some clay on the piston turn it over manually and try to mic it. I sure don't want to f-up mynew heads or the pistons.

krexken

If the heads are already on the engine, try it like this. Replace the #1 cyl intake and exhaust valve springs with some really light springs from a hardware store. You want one light enough that you can use your fingers to lift the valve off the seat easily. Adjust your rockers to normal tension. With a wrench, breaker bar, whatever, spin the engine slowly by hand. Carefully mash down on the retainer to feel for the piston coming up in the bore. As you slowly rotate the engine, constantly feel for the tightest spot by pushing the valve open, overriding the cam. Use a feeler gauge and measure the gap(lash) at it's tightest spot. This will be your clearance. Make sense? The hard part is changing the springs on the engine but the rest is gravy once you see what's going on.

Snafu

iTrader: (1)

Heads aren't on the engine yet. Right now it's block with timing cover buttoned up. Water pump and everything from there up is off.

I don't really have the means to remove the springs...any other options?

ArKay99

iTrader: (1)

If you don't want to change the springs there is really no way to measure p/v accurately. You can use clay, but you have to use a welded, epoxied, or solid lifter the exact same height as the hydraulics in there. You say you don't want to mess up your new heads, but you don't want to change the spring. It is just prudence to spend the extra money for a spring changing tool, you are going to need one in about 10-12k miles anyway, that's how long the springs will last. I bought the Vinci tool. It works great. You can do 2 springs at once. Do yourself a favor, change the springs, get a pushrod length checker, take the extra 1 hour of time to check your p/v and sleep well at night. It also is a good way to make sure you don't have the cam installed off a tooth. There were a lot of guys bending valves a little while ago.

Snafu

iTrader: (1)

I see your point...guess I just needed a good to motivate me...so here's a seemingly ignorant question...must I do this for each cylinder, or just the #1?

I have Comp Chromemoly 7.350" pushrods for this setup...this was what was suggested by my head and cam builders to match them. (so that's .050" less than the stock 7.400" pushrods)

While I didn't degree the cam (yes, I realize I should have) I have the cam and crank gears aligned perfectly...if even off one tooth, it makes a drastic difference. See the thumbnail below; the red line siginifies a straight-edge. How would you make an adjustment anyway given that due to the guide pin on the cam, there is only position you can bolt the cam gear to the cam?

ArKay99

iTrader: (1)

It looks like you are on the money. I meant that checking the p/v will not only give you a real number as to your clearance, but it will also tell you if you were a tooth off. I wasn't trying to kick you, but impress the importance of double checking your tolerances. Since you have gone this far, why not spend the extra time and effort to get the measurements and verify your p/v is correct? Not only that, when you are finished you will have the experience and the peace of mind of knowing your setup is 'safe'. Just think how much less your 'pucker factor' will be if you measure your p/v before you put it all back together and turn the key.

Snafu

iTrader: (1)

I gotcha now...

No offense taken, I just meant it took someone simply telling me to go ahead and do it for me to do it.

Yes, definitely don't want doubts...especially at the "moment of truth" when I crank it for the first time. No matter what, she's getting a few good manual cranks before that key goes in. I'll have to see if the local Advance Auto rents a valve spring tool.

Hey just noticed your in Mahwah...I grew up in NJ (Somerset County) and my grandparents lived in Pt. Pleasant...if I remember correctly, Mahway is nearby.

LS1 Swapper

Manual cranks won't do anything for you unless something is majorly out of wack, there is no substitution for properly measuring PTV clearance. I am going to say you will be having PTV clearance issues, was your 58cc chambers reached entirely by milling? How much was milled?

Best thing to do is install the cam and heads(before milling) with headgasket your planning on running and measure PTV clearance, then mill leaving a save margin of PTV clearance.

Snafu

iTrader: (1)

Yes, achieved from milling...I bought them as P&P'd 243 castings with option to angle-mill to increase compression...not sure how much they took off...it was supposed to be closer to 60cc but obviously didn't come out that way.

Nobody has mentioned it but doesn't the fact that I've gone with shorter pushrods assist in PTV clearance?

Well, until I get in there and measure PTV, I don't think there's much point in guessing...we'll just have to wait and see...

ArKay99

iTrader: (1)

I wouldn't trust the one the Adavance Auto will rent to you unless it is specific to LS1/LS6 heads. I had one of those 'cheapo' rental ones and messed up a retainer and an intake valve trying to get it to work. Those tools aren't designed to handle the aftermarket springs on a performance head. You may be able to get by with one, but it is a nasty bear to handle. It's sooo much easier with the right tool. PM me about the tool if you don't want buy one.
Point Pleasant is a great area. Not too far from Englishtown. My inlaws have a shore house in North Lavalette, about 5 mins from there.

PREDATOR-Z

Since your heads are still off, You can get a rental spring compressor from a shop (the C looking one) and replace one spring on each intake and exhaust (light one) on Cyl 1
You also get an old or used lifter and weld the cup to the lifter.
Then get yourself a dial indicator and measure your PTV properly.
Your Cometics are reusable so no worries. No need to fully trq the head either.

Also as i mentionned in the PM, make sure your head intake port deck has been properly angle milled, to match the angle change in your chamber deck. This is so your intake sits tight. The last thing you want is vacuum leeks.

As I also mentionned your are below 12.0:1, I calculated you at 11.92 but with a bigger bore gasket this gets reduced (by about 2cc) which puts you at ~ 11.77

Snafu

iTrader: (1)

I'm going to pick up some comp check springs and see about a spring compressor (worst case, I drive the heads over to a local LS1 performance shop a few miles away and ask them to take them off). Given the check springs are so light which minimizes pressure, won't this keep the lifter cup from moving? I've got a good dial indicator so that's no problem (that's how I got the PTD height measurement at TDC.

As far as the angle job, I left that in the hands of the shop I bought them from...how can I tell, just check carefully when I bolt the intake back up to the heads? Def. don't want leaks of any kind!

Yeah, when I first posted, I must've looked at my calculations from a .031" quench. I didn't even think of the gasket bore size effecting the SCR, but it makes sense...that was just the closest cometic gasket I could get with a .040" thickness.

REV dual springs good to 0.80" lift (I don't think valve float will be an issue)
REV coated stainless 1-piece valves: 2.02 Intake and 1.60 Exhaust
Titanium locks and retainers
Coated chambers, valves, and exhaust runners
Stock Lifters
Comp Pro Pushrods 7.350"
Stock Rocker arms

Combustion Chamber Size: 58 CC
Intake Runner: 216 CC
Exhaust Runner: 70 CC

LIFT INTAKE EXHAUST
0.10 79.50 64.1
0.20 150.3 108.1
0.30 221.1 161.4
0.40 262.9 192.7
0.50 283.8 215.3
0.55 288.5 222.9
0.60 289.5 233.5
0.65 282.4 236.6

LS1 Swapper

Not sure I'd run stock lifters...I never have so I can't say for sure

You can also order up some LSx intake manifold gaskets, which I believe are thicker. That mating surface to your intake manifold would be an issue so hopefully the shop milled them correctly.

The light checker springs will work fine with the lifters, its a bit hard to get the right load on the rocker bolt to get the rocker secure while not pre loading the checker spring.

ArKay99

iTrader: (1)

You can get an adjustable pushrod length checker from Comp. It is essentially a pushrod with one end that screws out. It's threaded so each turn is exactly .050". There is one that goes from 6.800" to 7.600". Just unscrew it to about 7.3". Make sure the lifter is on the heel of the cam. Then insert it into the hole and mount the rocker. Then you can unscrew the checker until it is up against the rocker. Then unmount the rocker and screw the checker back in while counting the number of turns till it's tight. Multiply the number of turns by .050" and add that to 6.8". That will be your zero lash measurement. Then add ~.060" to that and that is how long your pushrod should be. Also, you can run stock lifters as long as they are in good shape. I had my heads off so I bought a new set of Comp 850's.

Snafu

iTrader: (1)

Lifters are essentially brand new...engine has 2500 miles on it...so I'm not too worried about them.

I'm going to invest in the pushrod length checker, and check springs and get it all sorted out. I'm a little confused about the pushrod length tool, but I'm sure it comes with instructions.

As far as mating the intake to the deck of the heads, I sent an email to the guy that did my P&P job so I'm waiting to hear back on that. Why would I order more oem intake gaskets?