69427

While I've got my engine on the stand to swap out the cam, I was thinking of pulling the heads off while it's convenient to take a peek at the cylinders and chambers. And what the heck, while I've got the heads off I could spend a few more bucks while the credit card is still warm to replace the springs while I'm at it. I've done it on small engines before, but not on a BB or SB. I'm looking for recommendations on a decent (and affordable!) spring compressor, and any bits of wisdom and experience.

I appreciate the input.
Mike

derekderek

First you lay the heads on their sides and fill the ports with water. And see how much water drips past the valves. It tells you how good your valve seats are. Then you take the Valsprings off slide the valve down a little way and wiggle it back-and-forth and see how bad the valve guides are. Then you decide if you’re gonna want to spend a bunch of money doing guides and seats cutting the valves or if you’re gonna buy heads.

69427

Some no-cost checks while I'm there. I appreciate it.

Sigforty

As for springs, I have used the cheap rental compressor from the local store. It is not the best, but works if you dont mind spending the time. The best one I have used is from a local speed shop where I am friends with the owner. It is pneumatic and makes the job real easy. One trick is to use a magnet to grab the keepers once the spring is down.

derekderek

oh, this is a 427? numbers matching?

REELAV8R

I have one of these, for springs that are more than a single it's very nice and easy. The cheap ones you rent are a pain in the butt and the hand, hate them.


I use rope in the plug hole and run the piston up to hold the valves up. Use a magnetic pickup tool to retrieve the keepers. oops disregard, you're gonna have the heads off.
maybe with the heads off something like this. I don't have one of these. Just use the other one I have even with heads off.

Armybyrd21

This tool is well worth the $. Can do both heads in like 10 mins.

69427

This task is on my track engine. I've got the original engine stored away in the corner of the garage to keep from damaging something that's harder to replace.

69427

The heads are still on it, so my options are still open.

That first compressor looks to be handy.

stingr69

3 different valve spring compressors for 3 different uses.

The big Craftsman C-clamp is preferred for when the heads are off the car.

The small one on the bottom from NAPA is great to use with the heads still on the car BUT it will not work on dual or triple valve springs. You can turn the wheel by hand or pop off the wheel and use an air tool for faster work.

The lever in the middle is my least favorite BUT it can work with single, dual or triple valve springs with heads still on the car.

leigh1322

Oh I like the first one you found! Has anyone ever used something like this one on 550-600 lb springs? If so I may try it on mine.

The second one, when air powered, is what my buddy used at his head shop, with the heads off the block. It worked on the strongest race springs, and took like 2 seconds. I have used that one, it's terrific.

And on checking the guides for wear, pull the valve out 1/2", about max lift, then wiggle inside to outside (intake port to exhaust port), that's the direction they wear. It should barely move. There is a spec somewhere, but barely is close enough. Just compare it to the 90 degree direction, does not wear that way. If it passes that test, and the chamber holds liquid, you are good to go. Jeff would measure the width of the valve seat with a digital micrometer. I might have his preferred measurement somewhere...

sleepchamber

I just changed the valve seals on my 72 while still in the car with this tool. It was awesome and locks in the compressed position and is adjustable for position and compression force.

pspicci

The compressor above works pretty good. On mine however I had to bend the 2 forks down. At least on BBC heads anyway. Don’t know why they come with the forks bent up like that.

derekderek

track engine. did it have 20 years running time on the valve seals before it became a race motor? or do those valve seals have 50 hours use over 5 years. track engines break parts. they do not wear out parts. so, i think the heads can be pulled justifiably. but you are inspecting the springs, valves, keepers etc. and pistons-bores. seals most likely fine and many race and marine engines do not even have seals on the exhaust valves. the little bit of oil that gets in is a plus. and the exhaust guide is never under vacuum trying to suck oil in.

Chris Hewitt

With heads off the car you need to use the C-clamp style. The other styles will only work with heads on motor as the heads need to be anchored or they’ll just flop around on the bench. I’d get the Pro Form model. Looks beefy enough. The others C-clamp models shown are too flimsy and will just deflect. I learned all this doing my 427 rebuild. Wound up using my buddy’s vintage 50 year old C-clamp style compressor.

leigh1322

Derek has a good point. Track engines weaken valve springs, and then they eventually break, sometimes with bad consequences. It's the cycling and the heat that makes them lose spring pressure. So routine replacement before they break is a very good idea.

And if you are putting in a new cam, you may as well get springs that are very carefully matched to your new cam anyway.

I intend to re-spring my Winters aluminum heads in my newly built LS6, before I ever even install the engine in the car. Sounds crazy I know, but I want to run much lower spring pressure than the 250/550 springs I have currently installed. I have learned so much on this forum since that engine was built. I am only doing this as a precautionary measure for reliabilities sake, for better valvetrain wear, and less head cracking. And that means I will ditch the aggressive solid roller cam for a gentler-on-the-valve spring hydraulic roller. I originally tried to get-by with the springs that were on the heads when I got them, but have since learned that is not a good idea. Same end result as you, a new matched set of cam & springs, just for different reasons.

Rescue Rogers

Do it with the heads on the car. You will save time and money not pulling the headers, replacing header gaskets, draining fluid, pulling intake, replacing intake gaskets, pulling distributor, retiming it,.....

Get the tool that threads onto the rocker stud, get a rubber mallet to knock the retainer loose from the locks. A magnet to get them out, some grease to hold them on the valve while reinstalling them, either use rope in the plug hole or use a screw in air line connection to hold the valve up. I have a couple and they work well. They just need to get past the headers when screwing it in.

I have the square c clamp style for when they are off the block

69427

I read a couple reviews about this compressor, and BBC heads seem to be the ones that are a bit fussy untill the forks are modified. I looked at my heads, and to my eyes, it sure looks like the rocker stud and the valve/spring are not parallel. My first concern is that the compressor forks will put a side force on the spring as it compresses. My thought after that was if the compressor linkage makes an arc during its vertical travel (just like the rear wheels on our cars do with suspension travel), then the two items could cancel each other out.

So, as I've still got the heads on the engine (on the stand), I spent the fifty some bucks and am going to try the compressor when it shows up.

(Regarding why the forks are curved, my guess is that on engines (SBC?) that have studs and valves that are parallel, the curved shape might allow the compressive arc/force to walk over the retainer instead of sliding and putting a side force on the spring/retainer. Again, just my guess. I welcome correction if I'm FOS.)

69427

When I say track engine, I mean the non-original engine I built so that I could have fun on the track without worrying about hurting the original engine that came in the car. This is a licensed street car, but for any number of odd reasons, it spends more time on the track than on the street.

Just a guess, but I believe I probably have less than 5000 miles on these heads. I believe these springs are the correct specs for my new cam and lifters, and I'm trying to figure out which is better: Get these springs measured, or just spend the money and replace them.

derekderek

https://www.ebay.com/itm/31068290358...wAAOSw7Jpgx~Qx https://www.harborfreight.com/1-ton-...ress-3552.html here is 150 buck pressure testee. but i think if they all look the same and sit the same free height they are all probably ok. and the guide and rocker stud are parallel. what are the current springs? something under 130 seat 500 compressed to .600? a lever type will do the trick. i like clothesline fed in the plug hole. but i like pulling the heads more...