DaveBonds
Garage Trash
Coil clearances aside, what is the highest total lift that can be had on a factory, uncut LA head valve guide with a stock seal?
Max lift on stock guides and seals?
- Thread starter DaveBonds
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I'm no pro, but I have been told and have read .500. Of course if you factor in the loss from the 1.5 rocker than you might squeeze a little more.
DaveBonds
Garage Trash
Thanks, Bruce. That's what I'm reading and measuring loosely, with crude measuring tools. My mic's are at work! hahaha...
I don't think I'm going to freak out over cutting these guides. Especially on a set of used 1.5 rockers. I'm on a .489 exhaust lift, so I think I'll be ok.
I don't think I'm going to freak out over cutting these guides. Especially on a set of used 1.5 rockers. I'm on a .489 exhaust lift, so I think I'll be ok.
You should be fine.
Dave,have personally seen a .480/.494 hyd,clear a stock valveguide.Using 340 replacement springs.
71Scamper
Mopar runs thru my veins!
not to hyjack but I plan on putting a .507/.510 cam in my 340 with X heads. I have'nt measured anything yet but I'm wondering if i'm gonna have to do some extra machine work.
stock rockers...are not 1.5...probably close to 1.4...and you are going to lose another .010 lift due to the back pushrod angle in sb mopar..but if it was my engine I would check the clearance before I started the engine....
DaveBonds
Garage Trash
Good to know. I'm seeing a little room placing a 1/2" hex bar between the guide with the new seal on it and retainer.
And yeah, I figure I'm gonna lose some on original rockers.
I'll measure this up at work with a good internal caliper on Monday and post results, as I'm sure a lot of people want to know.
I've seen 0.530" on small comp cams seals. I've read .500" and I'm seeing at least .500" with my crappy tools on hand.
x2 always check...**** happens faster than it takes time to check
.............I have ran the comp 525 lift hydraulic cam with uncut guides...............kim........
DaveBonds
Garage Trash
Also good to know.
I'm starting to gather that from what Tony pointed out with pushrod angle, loose rockers and most places calling a .500" clearance, Mopar has gotten away with the .509 cam forever.
I'm not going to plan on cutting anything at this point, but I'll hit it with a caliper, anyway for everyone and myself.
fishy68
Tyr Fryr's Inc.
Most heads I've checked will handle right close to .500 lift and like Tony says due to the losses associated with less than advertised rocker ratios and pushrod angle loss a .510 or so cam will work fine. I did see one set of heads, 1973 587's I believe, that the retainer hit at .450 lift. Not sure why it was so low on that particular set of heads but it goes to show you it should always be checked.
DaveBonds
Garage Trash
That's why I was curious. Maybe it depends on the head? Maybe not even the number, but actually the particular head. Hughes calls caution on anything above .450" on their website, but on other pages of their site, reference .500"
The heads that I'm checking are a 302 and seem to have somewhere just over .500"
I have a few different vintage heads that I'd like to check and see where it makes any difference.
The heads that I'm checking are a 302 and seem to have somewhere just over .500"
I have a few different vintage heads that I'd like to check and see where it makes any difference.
moper
Well-Known Member
The older books always said .520 was it. That fit the "509" usage and like others said - between rocker issues and pushrod angles - you will lose at least .020" from that.
Hughes tends to match thier tech with thier parts as opposed to "Mopars in general". If they used a heavier spring - as in thicker wire or something - they may not get away with as much total lift because of the coil interference. The ramp speed of thier camshafts that have that shorter total lift may require heavier springs and thus require guide work. They also may recommend cutting the guides to run the positive seals rather then because of a lift interference issue.
Hughes tends to match thier tech with thier parts as opposed to "Mopars in general". If they used a heavier spring - as in thicker wire or something - they may not get away with as much total lift because of the coil interference. The ramp speed of thier camshafts that have that shorter total lift may require heavier springs and thus require guide work. They also may recommend cutting the guides to run the positive seals rather then because of a lift interference issue.
DaveBonds
Garage Trash
So, do you mean guide/ seal diameter against the coil?
Install height on spring interference would require retainer or spring seat work.
The coils are round w/flat damper inner that is short, so the damper isn't near the retainer or floor. They clear stock seals.
I agree with the Hughes specs, too. They definitely tend to their own gear and I can see why.
I'm beginning to think that from what fishy68 said about the '73 587's and what I've read on their site, they are probably aware of that issue, which may not be isolated to that casting and they're just giving a careful number and warning everyone to check for themselves.
Russ H
Well-Known Member
I bent all 16 pushrods due to coil bind on a 79 360. The cam lift was 480 advertized with 1.5 rockers. It's been a while ago. I don't remember the heads casting numbers but they were originals to the 79 Engine. Moral of the story, don't take anything for granted with Chrysler engines.
Also, I just had a set of 69 X-heads re-done with new springs installed. They measured for 520 max lift.
Russ
DaveBonds
Garage Trash
Interesting.
I'll have to check max lift on these springs @ recommended install height, against install height measured on what I have.
I'm wondering if you didn't have the same problem as above, with retainer to guide clearance? 587 heads are 2.02 1.60 360 heads.
As it was a long time ago, I'd ask if you saw the coils binding, or if there was any measurable gap in the wire, but that seems moot at this point.
moper
Well-Known Member
So, do you mean guide/ seal diameter against the coil?
No - I meant issues with coil bind as opposed to retainer to guide - sorry if I confused.
The coils are round w/flat damper inner that is short, so the damper isn't near the retainer or floor. They clear stock seals.
Yes - those are single springs.
You might have an issue with the 360s exhaust valves - they may have the lock groove lower than the intakes if the engine had the rotators on the exh valves. I know the 901-16s on my truck have a slightly heavier seat presssure than the intakes becasue of that. I removed the rotators but the lower groove remains. It's no issue - the cam is small - but it's something to watch for if you're not replacing the valves.
No - I meant issues with coil bind as opposed to retainer to guide - sorry if I confused.
The coils are round w/flat damper inner that is short, so the damper isn't near the retainer or floor. They clear stock seals.
Yes - those are single springs.
You might have an issue with the 360s exhaust valves - they may have the lock groove lower than the intakes if the engine had the rotators on the exh valves. I know the 901-16s on my truck have a slightly heavier seat presssure than the intakes becasue of that. I removed the rotators but the lower groove remains. It's no issue - the cam is small - but it's something to watch for if you're not replacing the valves.
moe7404
moe7404
i put a 68 340 4 speed cam with a 1980 360 head. the guide need trimmed. cant remember by how much. sorry.
DaveBonds
Garage Trash
I think I understand what you are saying, regarding coil bind. Getting rid of coil bind requires changing the install height on the spring to be taller, somehow, so you have to cut the floor of the spring seat or change retainers that have a taller height. I was thinking that maybe you were talking about coil against the guide or seal clearance, on the inside of the coil, I got it now, though.
I think any cylinder head with rotater retainers have a different, lower groove in the valve stem. The 302's that I went through had rotaters on the exhaust and the valve springs are significantly shorter on those. That brings up the possability that perhaps Hughes is giving a .450" measurement to take these retainers into consideration.
I did replace the valves in them as well as the retainers and locks. I'm still waiting on replacement springs from Hughes, so I haven't put anything together, yet, before measuring. I'll just double check the retainer to guide height and installed height of the spring against suggested install height.
DaveBonds
Garage Trash
Here are some numbers for anyone interested. These are from stock, standard LA valve sizes, using 4 groove exhaust and 2 groove intake valves (typical layout) on a 302 head. These are NOT stock, 302 valves. The locks are regular LA type/ layout in the grooves and total length. The 302 valves have a different, lock groove layout.
This info would be good for anybody attempting to adapt 302 heads on an LA to an aftermarket cam, with new valves on stock, uncut valve seats that only need lapping;
These dimensions are from the non rotater type, stock, .394" thick LA retainers at the inner/ lowest step to factory type guide seals, where lift clearance is critical-
Intake; .482"
Exhaust; .492"
These are to the factory type seals. Not the guides.
This gives an installed spring height from the floor to retainer as follows, again, with stock .394" LA retainers of 1.638" This may be a few thousandths tight, as it was difficult for me to get a good reading and will likely fall on the locks further once installed. I'll recheck height when I get the springs in.
Just for the hell of it, I measured the thickness of the rotaters that came on the 302's and they are up at .491", which requires a short spring.
The 302 intake retainers are skinny. Those were at .383"
This info would be good for anybody attempting to adapt 302 heads on an LA to an aftermarket cam, with new valves on stock, uncut valve seats that only need lapping;
These dimensions are from the non rotater type, stock, .394" thick LA retainers at the inner/ lowest step to factory type guide seals, where lift clearance is critical-
Intake; .482"
Exhaust; .492"
These are to the factory type seals. Not the guides.
This gives an installed spring height from the floor to retainer as follows, again, with stock .394" LA retainers of 1.638" This may be a few thousandths tight, as it was difficult for me to get a good reading and will likely fall on the locks further once installed. I'll recheck height when I get the springs in.
Just for the hell of it, I measured the thickness of the rotaters that came on the 302's and they are up at .491", which requires a short spring.
The 302 intake retainers are skinny. Those were at .383"
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