The Wrong Springs for Cam and Lifters

[Wbulk]

I am helping a friend fix his 347 Stroker that broke a couple of weeks ago. Luckily it stopped in his driveway. This is a show car that only has maybe a few thousand miles on it over the last six years. So, I thought I would post the damage and what was most likily the cause to possibly save others from this fate. The parts were all supplied by the machine shop that did the work and measured everything for the owner who wanted an engine with around 400 HP.


The heads were Edelbrock Vistor Jrs. #77189. The cam and lifters were from CompCams. The lifters were OE design with the spider and wishbones. Lift on the cam was around .565 as I remember. The machine shop charged the owner for checking the spring pressures but I suspect they really didn't. These heads are rated supposedly for 8,000 RPMs. Spring specs were 145 lbs. @ 1.900 closed and 380 lbs. @ 1.300 open. I took one of the springs to three different machine shops and got three different readings but the shop that did the work measured the springs at 145 and 380 lbs. this time.

Edelbrock has an installation note:
“Check cam manufacturer's specs for compatibility with valve springs. Recommended valve sizes listed.” There is no way Edelbrock knows what cam and lifters you are going to use, assuming the springs, lifters and cam are compatable can be a big mistake. In this case the #831 lifters cannot handle that high of spring pressure.

Comp's recommended spring for the cam was 120 lbs. @ 1.800 and 290 lbs. @ 1.259. The other issue was the lifters. In this case the stock style comp lifter might handle up to about 340 lbs., but at 380 lbs. in those heads, if you had a cam with .600 lift, you need a better tie bar lifter.

In summary, there are lifters and then there are lifters. They need the right spring for the right cam. I went with the Morel OE style from Howards Cams #91213, which is far better quality. However, be aware that with some after-market heads you have to remove the head to get them in. The lifters are about 1/8” taller than stock. This is not mentioned in the Howards calalog or on Summit's site. So, you may be in for another 100 bucks for gaskets. I called CompCams and was told they have redesigned the #821 lifter. The cost of fixing this engine in parts alone was about $900. The owner was really lucky the block was not ruined.

Someone else's engine:
[ame="https://www.youtube.com/watch?v=dcvWtQtsm-Q"]https://www.youtube.com/watch?v=dcvWtQtsm-Q[/ame]

[legenmetals]

You may need shorter pushrods as well as the gaskets for the taller lifters.

[Wbulk]

Yes, I checked them. The seat is about .015 taller but the body is taller still.

[legenmetals]

I noticed the rockers were 1.7 ratio with .565 lift. Did you find any spring damage or signs of spring binding?

[Wbulk]

That video is someone else's engine with the same problem. On our engine, no. It has 1.900 springs and can take a cam with .600 lift.

Added: No evidence of spring binding and no spring damage.

[blykins]

Nothing wrong with running those lifters with those spring pressures. To add to that, 120/290 is WAY LIGHT for a hydraulic roller and you will end up floating the valves.

Those heads are not 8000 rpm heads....145/380 are very typical hydraulic roller spring pressures and that's pretty much my go-to pressures for any hydraulic roller lifter.....OEM or linkbar. I've used the OEM lifters up to .640" lift with similar pressures.

I've never seen a lifter spider hold-down broken before....my guess is that the lifter was coming up too high and was binding on the hold-down.

This combination should have worked, no problems whatsoever. I'd be looking for a smoking gun.

[eschaider]

+1^ On what Brent said.

My other comment is engine builders and machine shops are different types of service providers. When you get the two confused you can be disappointed with the results. It sounds like your friend got the two confused. Some engine builders have machining centers that can also provide finished machining for the engine build.

Machine shops are just what their name implies — machine shops. You take parts to them and ask them to perform a particular machining operation you require. If you ask them to build your engine, they probably will. The build from an engine builder will probably be a better engine.

These events tend to be learning experiences. Think of the additional monies now being spent as tuition at a school. It is to the student's advantage to pay attention and get a diploma. This is a course you definitely don't want to take over.


Ed

[blykins]

If you use a standard base circle camshaft in a non-roller block, it can push the lifters up high enough that they will bottom out on the dogbones....

Was it a roller block or an older 302 block?

[tamanaco]

sorry to hear about his luck...or not so lucky. But, 8000 rpm heads, with hydraulic dog bone lifter and a spyder tray, with 120# seat pressure...I don't think so ...that RPM is solid roller tie bar lifter with 200# + seat pressures...OK

wiping out a cam with roller lifters...humm? oiling issue? something is major wrong...and it's not the cam, lifters or springs...it's oiling or lack of it! or some cheep azz chinezzee roller lifters! don't know

Was this a new engine build 5 years ago for your buddy? Got a build list of parts?

[legenmetals]

I'm wondering if you had any piston to valve contact from broken parts getting wedged.

This thread has my curiosity up as I'm currently assembling my first complete engine build. Usually I farm out the work, I have a lot of left over parts from different builds and I thought I would use them up.

I'm rebuilding the 302 68 J heads and have springs that tested 420 lb. @ .512. I'm using a Ross roller cam leftover from the Cobra build and installing it in a 289 block. I just started looking at retrofit lifters and I like the Lunati or Howards link bar lifters. Any suggestions?

[Wbulk]

The heads may not be 8,000 rpm heads but that's what Edelbrock says the springs are. I didn't say what springs I am installing, but I am not using the 145/385 lb. springs that were in the heads. For around 6,000 rpms max I will be using springs in the 135/330 lb. range. Longevity is a consideration.
CompCams has obviously had a problem with these lifters or they would not had redesigned them. There was no question in my mind that the heads were not a good match for the cam and lifters, that was my point. The owner let the machine shop make that decision which was a mistake. Crane cams also has a warning about not using the OEM style drop in roller lifters with very strong springs and recommends going to tie bar lifters if you do.

I removed the heads and there was no piston to valve contact.

I am concerned that the owner has a HV oil pump and I tried to talk him out of it the way the engine is built. All the bearings are good.

I stand by my original point. Be ware of using OEM style drop in lifters with very high pressure springs. If you buy the heads complete the head company has no idea what cam and lifters you are using. You have to check it out.

I stand by my original point.

Added: This is 91 roller block. Ed, I totally agree with you. The owner and I have had that conversation.

[blykins]

I would continue to look.

I was serious when I mentioned that I build combinations like this all the time. There is absolutely not one thing wrong with running OEM style lifters with those spring pressures.

Just because a company redesigns a part doesn't mean anything is wrong. Otherwise we'd still be driving Model Ts.

The high volume pump is also fine.

[Wbulk]

Good points but if a product works very well no company wastes time and money redesigning parts. Let's just say we disagree and leave it at that.

[Gaz64]

I've seen many roller lifters have needle bearing failure, hence why some manufacturers make bushed lifters, more bearing surface area.

If the bearing starts to overheat/seize, then the roller skids on the cam lobe, then it's all over.

Strange for 2 for have total failure like that.

I wouldn't use any factory type gear (Ford or GM) in a high power combination.

There are way better "tiebar" configurations available.

[olddog]

Wbulk

It seemed like everyone was piling on you for a few posts there. I don't blame you for feeling a bit defensive.

However I can assure you that if Brent is saying he does not believe the spring/lifter combo was the root cause to the failure, he is not doing so just to annoy you. He genuinely suspects there were other factors that lead to this failure. You should consider digging deeper.

No doubt there are better lifters available, and they may solve the real root cause to this failure. Be warned though that sometimes the real root cause, when left unknown and unfixed, will break the new better parts, too.

I have a 347 with Edel Performer RPM heads, with OEM style lifters. I didn't build the engine and do not know the springs ratings, but it will rev to a 7000 rpm limiter with no hint of float, so I expect they are heavy. No problems yet and over 5K miles.