Solid roller lifters, cylinder heads and more

[vector1]

on the solid roller cam from mike jones i'm running i was beating the backside of the lobe with the stock as issued afr205 springs which are 225/500 range and 3/8" x .083 pushrods. he advised me to change to a thicker wall pushrod and/or lighten the spring as the pushrod likely had too much spring. his suggestion was some lsx style beehive springs which use smaller retainers and/or going to a .120 wall or larger diameter pushrod.

just something to think about.

[blykins]

I'm not a fan of beehive springs, but they are rated differently because of their weight. The spring pressures are a whole lot less than a dual or triple spring.

If you ever buy beehives, buy the best brand you can...if a spring breaks, you've pooped the bed....whereas with a dual spring, you at least have a little bit of safety there before dropping the valve.

[madmaxx]

I think Ford is quoting behive springs for their new SBF 427. The advantage to a behive is you use alot less spring pressure to get the same result, in turn you minimize wear on valvetrain parts like camshaft, rocker arms etc. I think the odds of a spring breaking are the same odds of any other mechanical failure.

Originally Posted by blykins

I'm not a fan of beehive springs, but they are rated differently because of their weight. The spring pressures are a whole lot less than a dual or triple spring.

If you ever buy beehives, buy the best brand you can...if a spring breaks, you've pooped the bed....whereas with a dual spring, you at least have a little bit of safety there before dropping the valve.

[blykins]

He is experiencing impact loads due to lash. The only way he wouldn't be would be if he were running zero lash.

There's no way of knowing what the cam lobes or lifters look like until he pulls them and does an inspection.

Just because it's not floating the valves like a rev limiter doesn't mean it's not losing control of the valvetrain. This loss of control is magnified on a cast cam core. The cam will literally start flaking off.

Capri, are you 100% sure on the spring specs? If so, I'd like to say a few words to your engine builder.

How high are you pulling the engine? 5500? 6500?

[Caprimaniac]

"I have no idea why he is running solid rollers"
I don't know exactly what you mean by this, Madmmmmax. But to cut a long story short:

Was building a high- revving Hp 306. Destroyed two sets of cam and lifters (306 degree solid). All due to an unexperienced engine builder & hope to do it all on a budget. As a mean of getting by the cam run- in procedure the thought was: "Go roller! Longer open times, more radical ramps and no run- in."

And here's number two, to Brent: The heads purchased for no. 1 build was a set of Edelbrock Vic Jr's. And, again with an unexperienced engine builder, he went with a complete set of heads for mechanical flat tappet cam. As the 2. solid flat- tappet cam broke, he was furious and called comp cams to give them a lesson. He then got this answer: "The springs on these heads are too stiff for this mech. flat tappet; you will need a HUGE cam for these springs." (As a note: the cam in question was the 2. nastiest cam "off the shelf" from comp.) Then a close reading through the comp catalogue started; to find a solid roller cam....

And there it was: The nastiest Magnum solid roller. Spring pressures on "required" springs: 165/385.
Springs on the vic. Jr. heads: 145/ 380.
The person at comp cams said these springs MIGHT work OK...

As block was changed 2 years ago, the lifters and cam was beeing inspected as well; all looking well. No suspicious markings or anything on cam or rollers.
(As a remark: the car had not seen many hours of brutal driving by that time.)

As you can see, Brent, the spring pressures are very close to what comp advices for this cam.

Footnote: comp is also listing, in red letters, another set of valves for this cam; 977-16, which ahve pressures 155/420.

And if you need to speak to the engine builder; here he is- in person.

Let's think this over: If engine behaves well with these springs; no float at 8000 rpm, noe visible damage to the moving parts, noe debris in oil, no need to adjust valves after 10+ track days and with the fact that you should run the lightest springs "that will work" as possible to save the moving parts, I can see no problem in these springs involved. The statement of the need to run 450+ lbs springs (or whatever) on a solid roller is a truth with some modifications, as are also the "truth" in my arguments here.

I'm considering building a more streetfriendly 306 long- rod and therefore also thinking of switching the heads on the 347. AND therefore... I need to do research on what heads to use, what valves to use, what springs to use
and all other hardware involved. I will continue my quest and see about those valvespring pressures... If lighter valves are installed there will be consequences as well.


Now; one of my original question in this thread was: Will titanium valves do alot to make my valvetrain last longer and act more stable at the RPM's I'm spinning? Or do you have to move to 9000rpm to get real use of the lightweight valves? Is it worth the money, in other words.

rs

[blykins]

I can understand where you're coming from now.

The first comment I would make would be NEVER trust Comp Cams' tech line on ANYTHING. EVER. NEVER. First of all the springs on the Vic Jr heads are for hydraulic roller cams or flat tappet cams. They would have been just fine for each one of those. Secondly, the guy that gets paid $9 an hour to read out of a catalog doesn't understand that Vic Jr heads have larger, heavier valves than a lot of SBF heads. Comp tends to put a lot of "universal" information in their catalogs and while a spring may be good at a particular install height for a particular engine, it may be way off on another setup.

As I've said earlier, just because you don't get the tell-tale pop-pop-pop of valve float doesn't mean that you're not losing control of the valvetrain, especially if you're spinning this thing to 8000. I find it extremely hard to believe that a 145lb seat pressure can keep a huge solid roller lifter down on the lobe at 8000 rpm.

It's true that the Magnum lobes are not very wild. However what's not wild at 5000 becomes pretty funky at 8000 rpm. (It also means that you can step up to a Xtreme Energy street roller grind and pick up quite a bit of horsepower.)

Let me ask this question rhetorically: if Comp told you to go with the weaker of the two sets of springs in the catalog and you're turning 8000 rpm, why would they put the stronger set in the catalog as well?

As for titanium valves, they are found in a lot of OEM street applications here. Some of the Corvette LS engines have them.

They are $$$$$ and most definitely help on valvetrain control. However, I wouldn't consider it a return on investment unless you are in fact turning 8000-9000 rpms on a regular basis. Even then, there are probably some other options that you could try before hand. Those titanium valves are just horribly expensive compared to a stainless steel set.

[Caprimaniac]

Toutched tha backspacebutton and drove away to the Weber forum, but now I'll try once more...

Yes, Agree: "why would they put the stronger set in the catalog as well"? And tonight I found this in the Comp catalogue: part numbers in red are "the premium choice". Whatever that means!

Yes, I will follow some guidelines given here and move up the LBS scale on the valve springs.

What other means, besides going to Ti valves, can be done to make the valvtrain even more reliable?

I'm considering: Ti valve locks & retainers. Jesel belt drive & shaft mounted rockers. (Yes, I know. Darn expensive stuff. But, with 5000$ invested in the block, why not step up on other things, one by one, as well?)

Please feel free to come up wih other suggestions.

Let me ask this hypothetic question:

- If valves, retainers and locks are changed from steel to Ti; by how much can the sping LBS rating be lowered (everything else kept equal)?

- If locks & retainers are changed only, is there any reason to go down on spring rating? (I have not looked on the numbers, but it will be , I think, a net loss of 15 grams on each valve?)

And yes, it spins 8000+ every time the car is taken out for a drive, unless it's only to test the brakes or something on a sunday evening. How long it stays at 8000 is another matter because the racetracks where I live have very short straights. 1 lap takes about a minute and 5 - 12 seconds, and it's mostly turns. Top speed is 180- 200 km/h.

By the way: I'm on my way welding 2" pipes on the flanges (which I have cut off) from a set of "standard" Hedman 1 5/8" headers. To fit a set of Vic jr. heads. With standard bolt pattern....

Can the Vic jr. heads be drilled & tapped for widers exhaust bolt pattern? (I think the Glidden heads have this.)

Godnight.
Rus