bblythe

so this spring deal with this new retainers .What seat pressure are you seeing on the seat?

MILD THUNDER

iTrader: (3)

Eddie, as always that is excellent info.

So basically what you're saying, is there is more to picking a valvespring than just saying "I want 150psi on the seat". Those rockers prob take a beating off the seat once the spring pressure sags..??....Like bouncing on a pogo stick with a 7ft ceiling?

Cole2534

iTrader: (1)

I'm beginning to think the valvetrain is the most important part of the engine.

ACTIVESHACK

Brent the Stbd motor is the one that was replaced. The port has never been touched.

MILD THUNDER

iTrader: (3)

Cole, there is no such thing. There are a hundred plus parts in an engine, that if not right, will cause a failure. Valvetrain is just one area. But an important one for sure.

I will say, I have learned alot about engine builds in the past several years. The most important thing I learned, is assume NOTHING. The average guy, (including myself in the past), would bring a set of cylinder heads in to a machine shop for a rebuild. Never thought about things like, installed height, spring rate, coil bind, valve seat widths, angles, and so on. I'd always leave that up to the machine shop. I also never thought twice about questioning their quality of machine work. Heck, what did I know, Im just a weekend wrench. But as you go, and learn, and you start seeing things like valve stem heights all over the place from inconsistant valve seat grinding, installed heights varying from cylinder to cylinder, incorrect spring selections, shims slapped in place, valve seals getting ripped to pieces from not using spring locators, poor seat/bowl transitions, and so on. You start getting inconsistant chamber sizes, airflow issues, , different rocker geometry from cyl to cyl, all kinds of crap from shoddy head work. When shops let heads go out the door with big variances in seat depths, run. .002, no biggie, .020, that can be an issue.

The last shop I used to do my heads, did a decent job on them. They told me all my valve seats were junk, from the previous shop grinding the heck out of the seats. The springs, had been shimmed up, because between the longer valves I had, and excessive seat depth. After installing fresh seats, retainers, my springs came in right where they should have, without shims. Main problem I had with them, was lead time, pricing, and lack of communication. After getting a bill for 2500 dollars to refresh two sets of heads, (didnt include springs), no port work, they tell me, "oh, these heads been milled a bunch in the past, we cc'd them, and they came back at 105cc chambers". Well had I known that, I would have never invested 2500 into them.

I found a place locally, that my heads will go to from now on. I've known about him for years, as he has been there since the early 90's. He does cylinder heads, and that is it. He has no intentions on being an engine builder, as he simply says "I stick to heads, its what I do". Its a 1 man operation. The guy's attention to detail, is second to none when it comes to heads. Some of the local fairly big engine shops, outsource their head work to him, even when they have the equipment in house to do it themselves. From head porting,airflow, to the dynamics of valvetrains, he gets it.

Lots of engine shops out their, have a guy in the back, who they keep locked up like Sloth from goonies. His job is to work on heads, and gets paid in Baby Ruth bars. No thanks, I'll take the guy who sits at his bench with his vintage high powered spotlight, his reading glasses, and works on heads like hes performing open heart surgery. A guy who is proud to deliver your freshly rebuilt or ported heads, answers the phone, and doesnt take you to the cleaners when its time to square up. Sad thing is, he's a dinosaur and he knows it. With todays cylinder head technology and availabilty, the little mom and pop performance head porting/rebuilding shops, are a dying breed.

Young Performance

Thanks buddy. The rockers have to be taking a beating. That's the only reason that I can see why they are failing like they do. I would estimate that at least half of the 525's we get need rocker arms. Recently, we had a 2008 engine with 220 hours that had 13 of the 16 rocker arms that showed signs of a problem. As the needle bearings start to go, the rocker starts moving around and let's the poly lock touch the body of the rocker arm. They are easy to spot. If you see anodizing missing on the inside of the trunnion of the rocker arm, it's on its way out. I've posted some pics of them in the past. I'm in the airport at the moment but I can post some later tonight once I land.
Eddie

Cole2534

iTrader: (1)

Sounds very similar to an under-tensioned head bolt. Insufficient preload to hold things tight and then it gets beaten to pieces.

MILD THUNDER

iTrader: (3)

Makes sense to me. I was doing some maintainance last winter on my engines, which have the crane golds. I noticed some wear on the anodizing just where you are talking about. These rockers had very little time on them. After scratching my head, about WHY that was happening, I noticed some of the rockers had what seemed to be, ALOT of side to side play, when the valve was closed. Measured the polylocks i had. .550. Then, went and opened a new crane gold rocker I had in the package still, .600. HMM. Made sense now. I replaced all with the .600 locks, and 90% of the play was now gone. Apparently someone in the past, went to a speed shop, and said, "I need some polylocks for a BBC". Installed them and never looked back.

MILD THUNDER

iTrader: (3)

You do not want to get your heads rebuilt in this shop, by a guy who loves his "Rocky Road", a little too much. Reminds me of the "Magic Room" in this video. https://www.youtube.com/watch?v=dW9liiGyP_g

bblythe

in my experience with valve size we should be at 150 to 180 lbs at close and 500 at the nose. My background is drag racing.the stack hiegh is a diifer number than I have worked with1.820 /