dmruschell

I spent yesterday sorting out some rocker issues I created when switching from roller rockers to roller tipped rockers. I got it all sorted out, but noticed something that made me a little concerned, but wasn't sure if I should be.

I noticed that the valve springs were not centered in their retainers. I also noticed that (with the corresponding lifter on the cam base circle) I was able to slide the valve spring in its retainer.

To compare, I looked at a set of Summit Racing iron heads (supposedly made by Dart) I bought assembled for a 75 I'm bringing back to life. There is no way the springs on those heads can slide anywhere.

Here is a picture I took while reassembling yesterday. If closely inspected, it can be seen that most springs are not quite centered in the retainers.

Should I be concerned? Thanks in advance.

REELAV8R

The spring pockets "retainers" are too big for those springs. The spring is going to be moving around during operation and may cause valvetrain stability problems.
Take a closer look at the valve tip on the right, does it look oddly worn?

dmruschell

It was slightly damaged in the mess I was cleaning up. Some rockers had come loose while on a road trip, so I had to make do with what I could get, which wasn't optimal.

CanadaGrant

with REELAV8R. Also, if you look at the 2 rockers just to the left of the two that are removed, it looks like the rocker position on the intake valve is way off. The roller appears to be almost off the lower edge of the valve stem.
Edit: Ah...now I see the adjuster nuts are off.

dmruschell

That, and I replaced both guide plates to the left of the one I had removed in the picture. This picture was taken while I was still getting everything sorted and is not indicative of how things are now except for the springs not being centered in their retainers.

These heads were assembled by a local machine shop for a local engine builder who has built a lot of engines. I'm baffled as to how this was allowed to make it to my engine.

REELAV8R

The solution, as I see it, is to get some locators (outer or innner) that fit in the valve pockets to locate the bottom of the springs. This will change the installed height of the valve as well unless you can remove the same thickness of shims from each valve pocket.

Then I would toss those roller tip rockers. Probably what happened to you is the pivot ball wore down causing the rockers to become loose.

I had those rockers at one time and I could not keep them tight due to constantly wearing pivot *****. I've seen other guys have the same problem.

I can't believe an engine builder would leave the vavle springs unrestrained like that. But on the other hand Dart didn't do a much better job on the Dart SHP's I have. Ended up getting locators for those heads too.

dmruschell

I just downgraded to the roller tip rockers because of valve cover clearance issues. The problem was that the socket binds on the arm before tightening the nut all the way. I had read that some people got away with using the poly locks from a roller rocker setup. There was enough thread to lock the poly lock down, but they came loose on my road trip, messing up a few push rods and guide plates in the process, even when I checked and tightened sky loose ones every morning. AutoZone only stocks stock length push rods (this engine needs +.100), which was not optimal, but kept me going for a bit. One rocker ended up coming off of the valve stem on our way home, but I didn't realize it for a while because it was still quiet at cruising speeds. That caused the strange wear on that one valve stem that was pointed out.

I now have the correct polylocks and replaced all of the damaged pieces. So far, so good, though there is a bit more valvetrain noise than I'd like on the passenger side. Everything is adjusted properly and has been checked.

These heads are Liberty Performance 200cc heads, which I've read are foreign copies of Dart Pro1 heads. I didn't pick them. I thought the builder was installing AFRs, but I didn't know anything back then.

Edit (accidentally hit submit on my phone): These heads have 15,000 miles on them as-is and I'm not going to put a lot of work into them. If they ever come off, actual AFRs ( or something else that I pick) are going in their place.

REELAV8R

Sounds like a real pain with what you got.

If you find that those roller tips just won't work out you can use full rollers and still retain you stock height valve covers. You can use a thicker valve cover gasket or they do make valve cover spacers that will set the valve cover slighly higher to clear full roller rockers.

I use the crower SS rockers and they clear stock cover no problem. A bit $$$ though. Comp make a SS full roller rocker too a lit less $$. There are other aluminum rockers that can clear but it's on an expereimental basis, so you don't know for sure until you have them in hand.

Your valve guides could be taking a beating as well with what you got going on.

dmruschell

The rockers that were on the car were Liberty Performance aluminum rockers that were so big on the pushrod side that they would nick the side of the valve covers. Height wasn't the problem. Aside from being a no-name brand, I didn't want aluminum rockers for longevity reasons.

According to Comp, the roller tips (which I know don't really do much) will work fine with the cam I have (Lunati Voodoo 268). Hopefully their polylocks will stay tight and the pivot ***** will be okay.

I'm just continually annoyed at this engine, as it's not what I expected at every step of the way when I paid more for it than I would have for a crate engine. I guess ignorance is bliss lol.

REELAV8R

I get what you're saying. Learning about this stuff the hard way is annoying and sometimes expensive as well. I've been there.

If it were mine I'd check everything in that valve train. Pushrod length, rocker pivot *****, roller tip travel on the valve (geometry) and guide wear if you got the ability to do these things. If not get the opinion of a trustworthy engine builder, probably not the guy who built the engine.

Valve train problems can lead to even bigger problems down the road if not addressed in time.

Pop Chevy

It's common to see a little spring around the retainer, but if you are really concerned about it then pull one apart and check to see if the spring is seating in the retainer properly. The spring retainer should have a seat for the inner spring and outer and they should be a good fit. A little bit of play on the outer is o-k.

dmruschell

Pop, the heads have single valve springs.

I talked to a different mechanic who I trust and has built many engines, and he seemed quite concerned that the springs are as loose and as easy to move as they are.

Between that, the large 200cc intake runners, the lack of a heat riser, and foreign casting, I think it's time for a different set of heads.

dmruschell

The Dart SHP 180cc heads assembled with the dual springs are actually one of the sets I'm looking at. I'm disappointed to hear you had to get retainers for them. Do you have any other feedback about them?

REELAV8R

I also got the SHP 180's for roller cam and the pre-assembled SHP's are poorly set up.

The installed height is too high so that you are a long way from coil bind at full open. This creates spring control problems.

The spring pockets are all over the place as far as depth and hence so is the installed height. No locators and the pockets are too shallow so spring moves around excessively. So much so that the spring would snag a guide seal on occasion and pull it off the guide.

The 180 cc advertised intake runner size is way off. I measured them and they are in the 195 to 197 cc range.

The 64cc chamber advertised size is off. They measured out at 67cc's.

The valve seats are poorly installed and have curled aluminum and a large step coming out of the port.

The valve guides are loose and tight both. Too much variance. One was so tight it would have certainly seized had I not disassembled the heads to check prior to install.

Plenty of cast flashing in the runners and fat valve guide bosses.

In summation I would not recommend them to anyone. I probably won't buy Dart again, at least nothing less that a Dart pro head, and then not pre-assembled.

After farting around with them plenty they finally did work acceptably well. That was many, many hours later.

Even the locators I got directly from Dart were messed up and I had to modify 5 of them to get them to fit properly.

Got AFR's now and have had none of the problems I had with the Dart's.

dmruschell

Wow. I had talked to the guys at Dart yesterday and they were very helpful, but that is a pretty scathing review. Replacing a set of heads because of poor spring setup with another set of heads with poor spring setup (and similar size intake runners lol) seems silly. The Summit iron heads (Dart 165c Iron Eagles) appear to be set up beautifully, but I guess Summit handled the assembly.

Which AFRs did you go with, and what cam are you using? Did you notice any difference in power with the AFRs? At the top of my list in both price and desire are the AFR 180cc Eliminators, but I'd need to have them set up for a hydraulic flat tappet (which might mean buying directly from AFR).

gkull

They make a thing called spring cups. I use them on a set of heads that were machined for big springs and I only used 1.560 diameter.

Changing heads to pick up a few CFM is a moot point when you are not trying to produce very much power or rpm with wimpy 268 h-flat cams.

changing springs is an easy job.

I do wonder........ why would you not just install better valve covers to accommodate RR's? and who told you that aluminum RR's have longevity problems? All you have is wimpy springs and cam!

REELAV8R

My dealings with Dart on the phone were pleasant and they helped as well as they could. However it was never suggested that THEY had an issue in their quality control or that any of the issues I was experiencing was in any way a problem for them.
I don't mean to be scathing, just accurate. No reason for someone else to make a what?, $1100 now, purchase only to not get what they expected to get.
I now have the 180 eliminators from AFR.
I had them angle mill them down to 56cc's for compression. They did a pretty decent job. Got 56cc's on one head and 55.5cc's on the other. Close enough I suppose for what I'm using them for.

All of the valve guides measured out at exactly .002" clearance.

The 180 cc runners were exactly 180cc's.

valve seat inserts were well done with a good blend out of the port.

Some sharp points in the combustion chamber around the spark plug hole that were addressed when I smoothed and polished the ports.

Installed height was precisely as advertised.
I shimmed them up another .015" for additional seat pressure which put the spring very close to max lift of .600". This puts the spring close enough to coil bind for good control but not too close to be a problem.

So far I have been very pleased with the heads. I just pulled the valve covers at 2000 miles use to check the condition of things and there is no evidence of loss of spring control and valve guide clearance is still what they where when new.

I'm using a Lunati retro roller cam with a 270/270 advertised duration 219/219@ .050 on a 108 LSA with .549" of lift.
10.6 CR.

I haven't had it on a chassis dyno yet but it's putting out more power than the Darts were with a dyno'd 406 HP. I had to enlarge the main fuel inlet and add more intake air to feed the heads sufficiently.

It spins freely up to 6300 RPM, as far as I allowed it to go so far.

So I am pleased with the AFR heads. More $$$ for sure. And worth the extra $$ for the lack of the headaches and a well set up set of heads.

Live and learn as they say.

dmruschell

I wouldn't be changing heads to gain more CFM. My current heads have a (too big) 200cc intake runner, so chances are, whatever head I'd put on would flow fewer CFM than what I have, but be more street friendly.

I had valve covers that cleared roller rockers and used them for 50,000 miles. I wanted the look of the L82 valve covers.

Aluminum fatigues with no lower limit. It continuously fatigues until it fails when stressed. It might take a very long time, but eventually aluminum will fail. Steel fatigues, but unless catastrophically stressed, it will maintain a certain level of strength forever. The RRsvi had were also a no-name brand. But, that was secondary to wanting to use L82 valve covers.

dmruschell

Yeah, if I'm going to go to all of the trouble to put on new heads, I'd rather spend a little more, get exactly what I want, and not have to have any unforseen headaches. I think you helped make my decision for me. The only downside is the cost, but if the Dart heads aren't set up right, I might be giving a machine shop some money to fix the problems anyways, so there goes the cost savings.

I swapped intakes on the 79 today, but will probably put the heads on hold for a little while until some other car projects are finished up so I can use those cars while my 79 is having surgery. Thanks for your honest review of the Darts, and for sharing your experiences with the AFRs.

REELAV8R

Glad to help.
I'm in agreement that the 180 cc runners will give you a snapier better running engine over the 200 cc runners.
With the addition of the AFR's my engine is much more responsive than it was with the Darts. More velocity in the intake charge. With AFR's better flow as well that increases the velocity even more. Better cylinder filling at every level.
I'm at 4000 feet and intake velocity takes a bigger hit with the large runners than it would at sea level, as does the CR. Also one of the reasons for the relatively short cam.
The AFR 180's flow more air than the Dart 180's even though the Darts are actually 195-197 cc's.