"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
Well, alot of fun here!
Threaded Mode
