How To Set Valve Spring Height, install valve springs, Front Engine Dragster

In this video we will remove an old valve spring from a head, determine valve spring install height, install the needed shims, and install the new valve spring while the head is still bolted to the engine.
We will then test out calculations by measuring seat pressure with the valve spring installed.
It was pointed out to me that the springs I had installed on the new engine in the Front Engine Dragster did not have enough seat pressure for my expected top end RPM of 7,800.
What to do? My mentor, Steve Walczak, found a set of Comp Cam springs (#996) that were a good compromise between seat pressure and open pressure with the lift that I have.
My valves are relatively small, and light, so I can get away with a little lighter seat pressure. I will be shooting for around 338 pounds of force at close and just under 800 open.
I have a strong valve train, a copper struck solid roller cam (Engle), .135 thickness push rod walls (Trend), Shaft mounted Crower rocker arms. So…..it should stand up to these pressures.

[@yoloone65]

Thank you for the tutorial. I’m retired military and so I can really appreciate the attention to detail you put into this video.

[@ThrottleStopRacing]

Thank You (USMC)

[@dannorris1337]

You should make all spring pressure tests with the retainer on for all dual or triple springs as inner springs will add pressure due to retainer design. You then have to allow for retainer thickness in measurement.

[@danh.122]

Thanks for doing this video. I'm redoing an old set of GM 077 bbc heads, so I can build an L88 clone. I'm right at the point in the build where I needed this.

[@ThrottleStopRacing]

Thanks, take your time and you will do just fine.

[@jiavin25]

That was a very thorough lesson. I enjoyed it, thank you!

[@decorativeironplus4644]

Great Vid you did up very informative . i have always relied on the machine shops to set this stuff but here in recent times i have had so many do stuff that is shoddy id rather check things for myself to make sure its correct before running my engines this way i know its been done right thanks for posting this

[@ThrottleStopRacing]

No problem, glad it was helpful. Making the video helped me develop a method/process for doing this.

[@ronhodgkinson7683]

Nicely done and thank you for spending time with us

[@TheFastracer455]

I was happy to see it is a Pontiac engine, My only concern is that the more spring clearance can also cause harmonics and that's one of the reasons .060" is pretty much standard. Thanks for the video Sr.

[@ThrottleStopRacing]

Thanks for the input, the Pontiac is now gone.

[@TheFastracer455]

Sorry to heard that, I'm still holding on to my 495 cu/in 78 T/A and i'm in the process this week to replace the cam for a roller. Thanks for the reply. @@ThrottleStopRacing

[@dennishensley1150]

Now just do all 15 other valves and springs!! Cause he just did 1/2 of 1 cylinder. Jus what you have to do. He is really awesome !!

[@ThrottleStopRacing]

Thank you. If you do not like doing these things then they become a chore.

[@oneeyedsnake6914]

That is an actual car guy not a wannabe!

[@ThrottleStopRacing]

Thank you. Ha ha ha

[@matthewharrington2431]

Good video sir very informative. I’ve been Chasin how to do this for years. Thank you.

[@ThrottleStopRacing]

Thank you.

[@TheCarpenterUnion]

This is very well made for such a small channel. Gj

[@ThrottleStopRacing]

Thank you.

[@ianmatteson482]

Get a leak down gauge. Way easier than that rope. Bring the cylinder you’re working on to TDC then hook up air and you can do your thing. We tested our springs at a closer clearance on the dyno and picked up 50 horsepower by setting them at .060 from coil bind.

[@ThrottleStopRacing]

I have a leak down gauge. Used it in the click fast video studio.th-cam.com/users/video0xp99PKLNHA/edit I like the idea of that valve not being able to droop into the cylinder for what ever reason. Thanks

[@williamgrissom4142]

I just use an air fitting and thread by compression tester hose into the cylinder and hook it to my air compressor and that will keep your valves closed while you work on your Springs

[@ThrottleStopRacing]

That certainly will work. I live in fear of dropping a valve into a cylinder. What if there is a power failure, hose pop, you get the idea

[@williamgrissom4142]

Yeah I guess that would be a bad situation I run a large compressor with a stand alone Hobart 11000 gen/welder for those occasions . Thanks for the perspective and the reply.

[@TheGixxerig]

just to help you out put a touch of assembly lube on those keepers then they will stay where you put them good video

[@alexmiller499]

If you set every valve spring for Max seat pressure will the opening pressure be equal across the head. I am going to do this on my limited late model. Rules dictate the spring I have to use but I am trying to get more seat pressure, they allow us .030 shims

[@ThrottleStopRacing]

Opening pressure will be even for each valve, not sure if that means the pressure to open the valves evens out when rotating the cam. I would think it would depend on valve timing and if you have a Firing order swap in the cam? I just do not know enough to answer the question.

[@kermets]

Good info...but so many ads these days ...I think i will start buying books again......

[@ThrottleStopRacing]

I know, sorry, helps with costs

[@ragingsealion41]

Thank you. Lots of great info. Where did you get the spring tester for the vice with the mic?

[@ThrottleStopRacing]

There are different ones depending on the size of your retainer, this one is on Summit racing but may be the wrong one depending on the size of your retainer. www.summitracing.com/parts/pro-66841 If you have a racing license sure to register it with Summit as you get a discount through the pro shop (Jegs does the same thing)

[@redlinefury]

Nothing like working on an engine while seated on a rolling stool. My back is cooked from having to lean over to work on motors.

[@1978Rolla]

I removed the arms and back from an office chair and I love it. Best seat in the house!!!

[@v.e.7236]

This brings back memories of "slapping" an engine together, w/ zero measurements on any components, not valve train, not end play, nothing. And these engines ended up seeing significant mileage - 200K+ miles. Dumb luck? smh

[@ThrottleStopRacing]

Above all else you have to have some luck.

[@bwdz75]

Isn't the .080 clearance between each coil of the spring or is that total clearance for bind for all the coils of the spings together?

[@ThrottleStopRacing]

It is total. Thanks for the question.

[@bwdz75]

@@ThrottleStopRacing .080 is probably the total clearance as that is a large number, I haven't worked on a race engine in 20 years so on a normal grocery getter we just use a feeler gauge between the coils and run it around each coil from the bottom to the top make sure there is space between all of them as you can't trust head shops to install valve seats correctly or check height and I usually just send a head out and reinstall assembled

[@jameswieler3295]

@@ThrottleStopRacing Comp cams says " there must be a minimum of .060” clearance between the coils of both the inner and outer springs". This can be found at www.compcams.com/valve-springs-101

[@davidwiley2913]

Do you have an email I could resch you at? I have a question about how you got the cam lift

[@ThrottleStopRacing]

[e-mail]

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