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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.
In early July, heard a tapping sound that that was louder than normal and pulled the passenger side valve cover. The rocker on the #4 exhaust valve was sliding off of the valve stem every time the valve opened. That stem was work at an angle.
So, I ordered a set of AFR 180 Eliminators with 65cc chambers assembled with their their hydraulic flat tapper springs. I ordered them over the phone with Summit, which saved me a few $$ and allowed me to use the Summit Speed Card. They arrived in late July while I was out of town. I installed the AFR heads last week and, after 10 test miles, took the car on a 550 mile road trip without any issues (related to the engine, anyways lol). Performance is virtually unchanged from the old heads, but throttle response is very crisp, and my fuel gauge doesn't dive towards empty as quickly. So, I believe the engine is running more efficiently with the AFRs. The exhaust note is slightly more mellow on the highway with the open heat riser. Overall, I'm happy with the heads.
The valve springs are definitely not going to wander on the AFRs lol.
In early July, heard a tapping sound that that was louder than normal and pulled the passenger side valve cover. The rocker on the #4 exhaust valve was sliding off of the valve stem every time the valve opened. That stem was work at an angle.
So, I ordered a set of AFR 180 Eliminators with 65cc chambers assembled with their their hydraulic flat tapper springs. I ordered them over the phone with Summit, which saved me a few $$ and allowed me to use the Summit Speed Card. They arrived in late July while I was out of town. I installed the AFR heads last week and, after 10 test miles, took the car on a 550 mile road trip without any issues (related to the engine, anyways lol). Performance is virtually unchanged from the old heads, but throttle response is very crisp, and my fuel gauge doesn't dive towards empty as quickly. So, I believe the engine is running more efficiently with the AFRs. The exhaust note is slightly more mellow on the highway with the open heat riser. Overall, I'm happy with the heads.
The valve springs are definitely not going to wander on the AFRs lol.
Good to hear they are working out for you. Mine are quite crisp responding as well, it's the benefit of an appropriately sized intake runner and the resulting high velocity of the intake charge for the use of the engine.
I believe from my experience with the AFR's that you get more than just a name for the extra $$, you get the benefit of a quality product. My AFR 180's continue to run good and perform flawlessly.
Got bitten as reeflavr did also-its a shame that machinists or "tuners" will knowingly steer you towards crap parts cause they make a little more and you get to do it twice. Why some advertise a given size that is way off Ill never know; they can all vary a little but man....mine were close to 20cc more. Big fat fail, didnt know back then about this stuff
The heads that came off of the engine weren't horrible, and make about the same power (seat of the pants) as the AFRs on my 350. Since the AFR's intake runner is more appropriately sized for a 350, the old heads might even go well on a 383. They're supposedly Dart Pro1 clones. The driver's side head has no valve damage, but the passenger side has some abnormal valve stem wear on just about every valve.
I think I may get some correct spring retainers (cups? not sure if retainer is the correct word after doing some reading) to keep the springs from wandering and new valves for the one head and see what I can do with them. I'm sure it won't be the last time I work on a SBC.
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.
Hi, I resurrected this tread because it seems I have the same issues with my SHP heads. The valve springs are off centre on some valves same as in the pic.
The RH valve cover was leaking slightly so removed the cover and while it was off noticed a couple of small metal fragments by one of the head bolts so removed the rockers and figured it had to be valve spring remnants. Have only removed two springs so far (No 6 cyl) and found the ex valve spring in this state. After reading the older threads I'm thinking this issue is caused by the springs being able to "walk" around on the flat spring seat? Can this be remedied by different spring seats without pulling the heads? Never gave it much thought when I fitted the heads (they came pre-assembled). I have a lathe and was considering whether a collar machined to fit over the valve guide and inside the spring might be a fix?
FWIW I would not recommend these heads to anyone, on top of the above issue, when I fitted them I had to remove material from many of the pushrod tunnels to prevent the pushrods from rubbing against them. No 6 cyl Ex valve spring.
So you could order a set of these to help locate your springs in the pocket correctly. There are pages and pages of them on the Summit site, you just need to do some measurements on your heads to find the correct ones (pocket diameter, spring OD, Valve guide OD.) They can easily be installed without removing the heads, using rope or air pressure to keep the valves in place while the retainers are removed.
If you're concerned about the additional spring pressure or spring coil binding, you can also get offset valve keepers to restore original spring height. https://www.summitracing.com/parts/cca-4709-1 https://www.summitracing.com/parts/cro-86107x1-16
Really should start a new thread.
Just a couple observations and questions:
Are the guide plates slots too big? Maybe its the photo but they look a mile away from the pushrod.
Are the rocker studs too long? In other words, they bottom out in the head and never actually clamp down the guide plates. I see oil under the removed plate. That indicates there is a gap between guide and head.
Those rocker studs take a lot of torque to secure them properly. Maybe 50 -60 lbs? Don't recall off hand.
Really should start a new thread.
Just a couple observations and questions:
Are the guide plates slots too big? Maybe its the photo but they look a mile away from the pushrod.
Are the rocker studs too long? In other words, they bottom out in the head and never actually clamp down the guide plates. I see oil under the removed plate. That indicates there is a gap between guide and head.
Those rocker studs take a lot of torque to secure them properly. Maybe 50 -60 lbs? Don't recall off hand.
The first pic is from the original thread, not my heads. My guide plates are tight and the pushrods are a close fit in the guides:-)
So you could order a set of these to help locate your springs in the pocket correctly. There are pages and pages of them on the Summit site, you just need to do some measurements on your heads to find the correct ones (pocket diameter, spring OD, Valve guide OD.) They can easily be installed without removing the heads, using rope or air pressure to keep the valves in place while the retainers are removed.
If you're concerned about the additional spring pressure or spring coil binding, you can also get offset valve keepers to restore original spring height. https://www.summitracing.com/parts/cca-4709-1 https://www.summitracing.com/parts/cro-86107x1-16
Thanks I will check the Summit list out, I've just spent a couple of hours looking at the JEGS site for the same thing but no luck so far.
The flat washers fitted currently are 1.500" outside diameter
The spring outer diameter is 1.263"
inner diameter is 0.791"
Valve guide is 0.559" diameter
Found these ones so far -
Comp cams 249-4693-16 OD 1.30" ID .570" spring ID .800"
Comp cams 249-4776-16 OD1.55" ID .570" spring ID .790"
Both of these would be a sloppy fit onto the valve guide how critical is this measurement?
Thanks I will check the Summit list out, I've just spent a couple of hours looking at the JEGS site for the same thing but no luck so far.
The flat washers fitted currently are 1.500" outside diameter
The spring outer diameter is 1.263"
inner diameter is 0.791"
Valve guide is 0.559" diameter
Found these ones so far -
Comp cams 249-4693-16 OD 1.30" ID .570" spring ID .800"
Comp cams 249-4776-16 OD1.55" ID .570" spring ID .790"
Both of these would be a sloppy fit onto the valve guide how critical is this measurement?
If you have the money, save yourself the headache and buy some quality heads. You will not be able to get the installed height sufficient high enough to control the spring surge through coil proximity at full lift. Well...I guess you could get shorter valves. But those SHP heads were such a disappointment for me I just decided to shelve them.
04-20-2017, 04:13 PM
