You will need to rent or buy the tools to pull the balancer and press it back on.



Posted this pic just for the shot of the guides and studs.

 

Ive got a balancer puller in my arsenal. I usually tap them back on with a block of wood and a mallet until they are close and then just torque the crank nut down. Is there another way?

Im really the most concerned with swapping out the springs. Ive got the lever type spring compressor but I dont know If Ill have enough room to get to all of them while still in the engine bay. I also know how touchy theycan be and sometimes the valve keepers need a whack to unseat themselves. Is there a better way to keep the valves up other than compressed air? I read once about a guy who kept filling the cylinder with 3/8 rope....if I have the cylinder at TDC, can I just let the valve drop? Will I be able to compress the spring enough to hook it back in?

 

I've used rope when leaving it overnight or when air isn't useful. It works pretty good. My favourite is 3/8ths yellow nylon cord as it doesn't shed and is easy to slide out after.
Sounds dumb, but it works....

 

You should buy or rent the tool to press the balancer on. You don't want to be hammering on the crank. I can't tell you the exact reason, maybe it's messing up the crank thrust bearing. It is just not the recommended way to do it.

I have changed springs in the car on my 427. I was also worried about holding the valves up. I beat the center out of an old plug and threaded an air fitting into the plug base. I thought I needed the pressure on the valve face to hold the valve in position while I smacked the retainer/compressor foot, but the valves opened anyway when I popped it with the hammer. After a few valves, I didn't bother with the air anymore. I would use the compressor to slowly push down on the valve retainer to see if the valve stem hit the piston, then I would turn the crank to drop the piston down a little if needed. I only had to move the crank a couple of times total. I then squeezed the spring some, not a lot, and got to the point where my arm got calibrated enough that one or both locks would come flying off when I used the hammer. I was surprised how little the valve moved. The first time that the locks flew off, I was worried a lock was going down the oil return, so I put a rag at either end of the head to plug the holes. I didn't mess with the crank/piston position much at all, but I wasn't cranking down hard on the compressor either. The more pressure on the spring with the compressor, the more resistance you have to the retainer/spring moving when you give it a shot with the hammer. If your valve seals are good, and yours are new, the valve stem slowly slides down. I never had a problem losing the stem below the seal, but I always moved quickly doing the swap of the springs and any shims. This was not on the current engine that has the Chris Straub cam.

Do you have a valve micrometer? After I decided to buy the cam from Chris, I measured the installed height of the intake and exhaust valves (distance from the top of the existing shims to the bottom of the retainer) and Chris picked a set of springs that would work with that installed height on his cam. So when I was swapping valve springs, I didn't have to mess with changing shims. That made things easier.

 

When I was in the Army, we had a saying: "If it's stupid, but it works, then it's not stupid."

Scott

 

Chris hasnt mentioned anything about springs yet, but he did quote me for them in the cam package. Ill be getting the car home from the paint shop on monday and Ill be able to identify my heads then. Will he need the valve height measurements?
So if I understand correctly, you are saying the valve seal alone gives enough resistance to hold the valve in place? I have a tool thats specially threaded for this purpose (threads into spark plug hole) and I plan to play it on the safe side. Dog help me if I drop a valve into the cylinder....

 

How to properly install a harmonic balancer cheaply.........

Go to an Auto Parts Store like NAPA buy a 7/16 fine thread "spring center bolt" for leafsprings, buy a hardened grade 8 nut and a stack of hardened washers. Use plenty of anti-seize, lightly install the harmonic balancer, thread the center bolt into your crank snout, tighten the nut and put your balancer on in a way that wont DESTROY your crank thrust bearing surface/crank snout/front of balancer. Learn how to repair you Vette the proper way for many years of reliable enjoyment.

 

If you don't measure the installed height, then Chris will supply a set with the right spring rate and he will tell you what the installed height needs to be. Then you may need to monkey with shims during the critical time when the locks and retainer are off the stem. Maybe I just lucked out, but the idea of me measuring the installed height first was so he could try to hit it with the new springs, which he did.

I didn't give you the right impression in what I wrote above. I didn't have the air on for 14/16 = 88% of the time, but that doesn't mean that I was unconcerned about a valve dropping in. The seals were pretty new and the drag on the stem from the seal wasn't enough to hold the valves in one place, but it did make for a slow motion effect. I'd pull the stem up and then slip on a shim, grab the stem again and pull it up and then slip on the spring and retainer. I had my spring compressor set-up so it would go over-center and hold the spring compressed when I was putting everything back together, while I got the locks in place, and then released the pressure. On the first several valves, you are clumsy, then the process speeds up. This last time around, I was cheating and doing it all with the heads on a work table, so I didn't have to worry.

 

maybe you could mill your current heads a little to get the compression you want.what intake are you using ?

 

What a cool and inexpensive idea!
Good one Solid LT1.
I spent sixty bucks on a harmonic balancer installation tool. It will work on many engine types, but I'm not in the business so it was much more tool than I needed.

Pete

 

I guess Ill have to see what Chris advises me to do. As far as the valves dropping, wouldnt rotating each cylinder to TDC bring the piston up close enough that even if it did drop, it will only drop maybe 1/4 inch onto the top of the piston?

 

Scott,

I wouldn't feel comfortable with the piston that close. I'd be worried about bending the valve stem by impacting the piston. The act of compressing the spring doesn't break the valve locks loose, it's the inertia of the valve and locks when you blast the spring retainer that does it. The retainer and spring move, but the valve and locks stay where they are if you do it right. But while you're practicing, it all moves as one and that's when I'd be concerned, when you trying to figure out how hard to drop the hammer, you might run the valve into the piston.

I haven't done this job on the car in 10 years, but I had to do it twice within a short period due to changing cams. The second time around, I may not have even used the spring compressor at all. I had a 1/2" drive deep socket that was roughly the inside diameter of the outer spring and a short 2 lbs. hammer. I just set the socket on the retainer and gave it a shot or 2 and the locks flew off and were contained in the socket. I might have done this where is was too tight to use the compressor, like on the no. 7 cylinder, the first time I changed the springs. I must have been rotating the engine as I went when I did it this way, I was always more worried about bending a valve than losing the valve into the cylinder. Quite frankly, it's been a while. BTW, I obviously had to use the spring compressor to put the locks on with the new springs.

What have you other guys done for getting the springs changed on the car?

 

A change from 113cc to 101cc chambers would only change the compression by about 3/4 of a point, to ~9.25. How much milling is allowable? Is this right, 0.005" milled off is about 2cc on a BB head? Not sure.

 

From what I've read in his 2 related threads, I don't think the OP has verified what pistons he has or has done a compression test to get a ballpark idea of what his cylinder pressure is. I would think Chris would want to confirm that basic info before designing a cam. I think Sealed Power shows a listing for the pistons shown on the OP's paperwork (per his original thread), so a call to Sealed Power would sure make sense to me. Also, without upgrading his current heads to bigger valves and adding some port work I think the gains from the new cam would be limited, not to mention that his original intent to locate closed chamber heads might net a better overall gain with his old cam than a new cam with his current heads if left unmodified. This assumes that the closed chamber heads would have the larger valves like the Edelbrocks do.

A buddy once put a performance cam into a low compression small block and it ran like crap because of low cylinder pressure. Chris is a master at cam design, so I'm not saying that would be the outcome in this case but I do think he's being limited in how much good he can do with the current heads.

It's late and I'm tired. I hope this makes sense and maybe helps the OP consider his options. Power costs $$$ and you sometimes have to hold off until you have enough of it to reach your goals.

 

Les,

First off, you are making perfect sense. The OP doesn't know what heads he has either, so there were plenty of unknowns. But as the OP wrote, his car will be back soon and he can verify the heads. Good point on chasing down the pistons. My point was that a 12cc change in chamber volume only yielded a 3/4 point compression change. I don't know, but I think it is a stretch to try to make that magnitude of a volume change from milling the heads. I just had a set of 110cc Edelbrocks skinned 0.010" to get them flat and that only resulted in a net 1cc volume reduction because of some chamber work.

My Vette brother changed from a 69 427/390 head (2.06/1.72 valves) to an Edelbrock 290cc 110cc chamber aluminum head with 2.25/1.88" valves. There was no 75 HP change, let alone 100 horse increase, so I'm a little skeptical on how much change a head swap would make, although I'm a big fan of getting the compression up. Chris says "High compression makes my job easier".

A properly tuned 427/390 would give a 435 a run for it's money for most of a quarter mile. I've had 2 435s and my buddy had a 390 and an L89 at the same time. The 390 had crazy throttle response. If the OP's engine has the factory heads, they are large oval ports, essentially identical to a 69 390 head, except for the smaller spark plug and the open chamber, which is supposed to flow better. So, I think you could make a pretty fast street engine with those heads with the right compression and in this case it's the right dynamic compression taking into account the low static CR. If it was me, I'd swap pistons first and get the compression around 10.5:1.

 

Just to be clear, I wasn't questioning your thinking at all. I quoted you because you were discussing chamber volume and the related change to the compression ratio and that took me right into what I was thinking about. I agree, you can definitely make a strong street engine with the heads he has if you put the right combo together, although the bigger valves do make a difference. I had the bigger valves and some pocket porting done to my original 390 HP heads. I did a cam swap at the same time so it's not a direct comparison but it made a big change in power output- FWIW the cam that came out was a performance cam but specs were unknown to me when I bought the car.

I get that the OP wants to minimize his cost. Frankly, I'd tune the ignition and carb first and see if that's enough to be happy. It's amazing how much difference it can make when you make sure the carb is working properly and also have the right initial timing combined with as quick of a curve as the engine will allow. If he truly does have a low compression combo, then if he could get a good price on a set of closed chamber heads that have been modified like mine, he'd have something that could make good use of whatever cam he chose.

 

[QUOTE=
I get that the OP wants to minimize his cost. Frankly, I'd tune the ignition and carb first and see if that's enough to be happy. It's amazing how much difference it can make when you make sure the carb is working properly and also have the right initial timing combined with as quick of a curve as the engine will allow. If he truly does have a low compression combo, then if he could get a good price on a set of closed chamber heads that have been modified like mine, he'd have something that could make good use of whatever cam he chose.[/QUOTE]

My carb has been recently tuned by Lars, so I have no doubt its running fine. I dont know yet where my timing is yet but its not showing any timing related problems so I know its in the ballpark.
Ii seems this thread has boiled down to 'heads versus cam'. Everyone seems to have their own theory. The ONLY person to give me solid numbers based on my current build (including head assumption) was Chris. He said his cam would net 75-100 HP ,which is more than Id expect for a set of heads. Its not as much about money right now as it is the 'what do I do next' phase. I want upgraded performance, I dont want to change pistons and it seems everyone has there own theory on what will produce the most seat of the pants increase. Im going to spend more time talking with Chris, ill give him every detail of my car, and hopefully hes still confident that he can squeeze me an extra
75-100 hp.

 

I think in this case the cam offers more bang for the buck. There are multiple benefits to roller cams, one of which is longevity. It's expensive but just upping the compression with heads won't be of much benefit due to the less than stellar cam.

 

Especially seeing that Ill only loose 2CC's if I get it milled, and actually gain CC's (and DROP) compression with most large combustion chamber aftermarket heads. Im sure I could find a set of factory closed port heads but theres too much unknown about buying from ebay. (thats what started this whole thread)
Badrad has it correct. Bang for the buck.

 

Scott,

If you make this cam swap and stop there, I agree with Badrad and think you are also maximizing your return on investment. I get it that this is your engine and your money. The reason I've been an A-hole about the pistons and jacking the compression is this, if you follow the natural progression of things, you're going to eventually change to aluminum heads for better flow and bigger valves. This has the effect of dropping your CR about half a point due to better heat transfer characteristics of aluminum. If you go with the Edelbrock 100cc heads, you'll still pick up about a net 0.25 in compression, but that's the head you're stuck with and they don't flow all that well without porting work. Any other aluminum head and you'll have a net loss in compression. This is just an explanation of my thinking.