Small block cylinder head specs

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Larry Hutchens

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I know that this is not a specific A body question but someone out there may know where I could find the info that I need. I am rebuilding a 360 engine for a B-350 van & am in the need of dimensions for valve stem height & installed valve spring height for the exhaust valve w/ valve rotator retainers. I have the correct dimensions for the intake valve which is the same as most other LA engines. I already know that I can get a valve for a non rotator style retainer & just use the retainers like on non rotators but would like to stay w/ the rotators for durability reasons. Also don't trust aftermarket parts that come from who knows where w/ questionable quality & unknown durability. I have FSMs for an 83 & 88 B-vans but the info on spring height is either confusing (doesn't specify for ex. valves w/ rotator) or has to be completely crazy, listing the installed height for one valve to be 1 1/16", just can't be. Also, for the intake valves, does anyone know of a supplier that has US made valve springs? I am an experienced engine builder w/ all the necessary measuring devices. Help would be greatly appreciated.
 
Rotators can be on both valves. And the installed height of the springs is short, I can't remember exact numbers. The intake valves have the valve lock grooves cut low also. Do you have the heads apart yet?
 
Isky sources some springs From Associated in So Cal as well as PAC and - what's the other one- brain fade
Lunati has PAC springs - but specify
but specify
I'd PM Dart19666 Shaun and Crower and ask your question
I've replaced many rotators but if you are actually doing a HD engine they do help
The installed height is tight- a short spring- so BVVC with your exhaust cam lift
There are several camgrinders who have "dwell cams" lift limited for certain classes or to fit with stock retainer to stem seal dimensions etc
let us know what your are thinking
I can say unequivoquely that a cam with shorter than stock or stock seat durtations with a little more lift but more area wear better than stock, valves run cooler as they stay on the seat longer
If you can get some quench with the KB quench dome pistons and stock 360 LA heads
(this is not a magnum is it?)(or a late roller cam block?)
post the 3 digit number from your heads
and this may be a Truck/industrial motor given the rotators
usually a double roller timing chain and much better valves
but sometimes lower compression
which means you have to give it more throttle to get the same power which gives more heat
the lower the compression the more heat
we built many 360 and 440 motorhome motors years ago
 
what 66 said
if heads are not off run a compression check
if off measure the compression distence- piston top to deck at all four corners and post back
also describe the piston top - dish, 4 valve reliefs etc
if engine is apart measure the center of pin to piston deck
doing the cam and quench can reduce your EGT by 5-600 degrees on a 360 and 800 degrees in a 440
 
I'm reading into the op's question and it makes me wonder if he's just going to try and stick the spring at the height it's supposed to be at instead of actually testing the spring and setting it where it gives adequate pressure.
 
66fs said:
Rotators can be on both valves. And the installed height of the springs is short, I can't remember exact numbers. The intake valves have the valve lock grooves cut low also. Do you have the heads apart yet?
Click to expand...
Yes, heads apart, cleaned & fresh valve job. Also have the installed spring height measured. I have no reference dimension to work with.
 
Wyrmrider said:
Isky sources some springs From Associated in So Cal as well as PAC and - what's the other one- brain fade
Lunati has PAC springs - but specify
but specify
I'd PM Dart19666 Shaun and Crower and ask your question
I've replaced many rotators but if you are actually doing a HD engine they do help
The installed height is tight- a short spring- so BVVC with your exhaust cam lift
There are several camgrinders who have "dwell cams" lift limited for certain classes or to fit with stock retainer to stem seal dimensions etc
let us know what your are thinking
I can say unequivoquely that a cam with shorter than stock or stock seat durtations with a little more lift but more area wear better than stock, valves run cooler as they stay on the seat longer
If you can get some quench with the KB quench dome pistons and stock 360 LA heads
(this is not a magnum is it?)(or a late roller cam block?)
post the 3 digit number from your heads
and this may be a Truck/industrial motor given the rotators
usually a double roller timing chain and much better valves
but sometimes lower compression
which means you have to give it more throttle to get the same power which gives more heat
the lower the compression the more heat
we built many 360 and 440 motorhome motors years ago
Click to expand...
 
Please explain the PM Dart19666 part. I'm not familiar with the names of the springs, PAC & Associated. Yes, the rotators are almost a requirement for a HD engine. It is in a class-B motor home & fairly heavy but the weight is not as much a factor as aero drag. A class b is just a regular maxi-van but w/ a high fiberglass top. Engine is stock bore & crank. All were in good shape w/ only .001 to .0015" taper on the bore. Just a re ring & new bearings. And the timing chain was double row. Replaaced w/ a melling unit. Engine is LA block w/ flat tappet hyd. they didn't start the roller cams until the next year & not in all engines for the 360. Did a 360 LA out of a 1 ton dually a few years ago & it had the roller w/ TBI. Compression is factory but I had the heads milled to make sure they were straight. Probably no more than .010". 3 difgit head casting 596, block casting has no dash # after the 360. Motor has not been replaced. The cam is a regrind from Oregon cams. On cam specs: Best info I can come up w/ shows 2 grinds for that year w/ 360 & 4bbl, single ex. In lift of .372", ex .400", dual ex In & ex .409". my regrind has .400" in & .417 on ex. Shouldh't have any issue w/ spring bind w/ only .008" more on the ex side. Yes, truck, B-350 van. To give it a bit more advantage I am using magnum ex manifolds & increasing the single ex to 3" from the existing 2.5". I trust the original stuff way more than a lot of the aftermarket stuff we are getting now. Chrysler stuff good. I've built a lot of these engines in a similar way that I'm doing this one & have had real good luck, just nervous about using aftermarket valve springs & can't find a direct replacement for the ex w/ rotors.
 
Wyrmrider said:
what 66 said
if heads are not off run a compression check
if off measure the compression distence- piston top to deck at all four corners and post back
also describe the piston top - dish, 4 valve reliefs etc
if engine is apart measure the center of pin to piston deck
doing the cam and quench can reduce your EGT by 5-600 degrees on a 360 and 800 degrees in a 440
Click to expand...
Short block is assembled & used the factory pistons so compression is factory. Not building a perf engine just one for a van that has to be reliable. Simply can't find the valve spring specs for the ex valve w/ rotors.
 
sealed power has the springs
so do others
they should have a dampner
melling/ clevite 2121297
it would be more reliable with modern pistons
 
MOPAROFFICIAL said:
I'm reading into the op's question and it makes me wonder if he's just going to try and stick the spring at the height it's supposed to be at instead of actually testing the spring and setting it where it gives adequate pressure.
Click to expand...
Would like to replace springs but they seem to be un-obtainable. Cannot find a source so I'm forced to try & find some aftermarket unit that fits the specs. Problem: can't find the specs, I have my measurements but cannot locate factory specs. FSM not much help, it is as if they made those engines w/ rotors then forgot that they existed. FSM example: 1988 B-van has 3 columns for installed valve spring height. 1st column is for 318 & 360 & reads 1 5/8" to 1 1/16". This is likely a typo & should read 1 5/8" to 11/16" (1.625 to 1.687"). Next column is for 318 only & reads 1 29/64" to 1 33/64" (1.453 to 1.516"). The last column is for 360 & reads the same as the previous column. The measurement on my cyl heads varies from 1.455 to 1.460 which falls in the specs for both the 318 & the 360 but the manual doesn't specify if the dimensions are for intake or exhaust which in my case are different. I can assume the dimensions for the 360 are what I'm looking for but I do not like to build something based on assumption. Therefor I can only say that the FSM is confusing & vague. Free length for the ex valve spring is 1.810 & it has a damper. My machine shop is searching & (so far) has come up w/ zilch. Also need the valve stem height & (again the machine shop cannot locate.
 
Dimensions?

You have your installed height, same for both. 85-90 seat pressure should be fine.
Don't over think it but be certain of the seat pressure. It's.395-.400 lift and 195 [email protected] so it doesn't need much for open.
 
Wyrmrider said:
good question
83 is different than 88
so question is
Is this a 360-2 or -3
vin would help and numbers off the block is there a K in the ViN
what spark plugs ?
2bbl or 4 bbl
hyd flat tappet or hyd roller lifters
etc
360-3, What's the difference? - Moparchat - Home of MOPAR enthusiasts worldwide!
Assistance Needed, Heavy-Duty Dodge 360 Owners?!?
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Need Mopar 360 block and head Casting info help
Click to expand...
Most spesc for the 360 between the 83 & 88 models the same except the cyl heads. 1) there is no dash number after the 360 on the block. 2) 1st 4 digits are 2B6K. 3) Spark plugs same as 318 360 all the way back to mid 70s. Unaware that they had a plug change until the magnum engines. 4) 4bbl Q-jet w/ single exhaust. They started using Q-jets in 85 when Carter quit making carbs. 5) Flat tappet. Hyd rollers started sometime in the 89 year. I have an 87 318 in a Duster that is roller but I've not seen rollers in a 360 until the 89 year which is also theyear that they dabbled in the TBI system.
 
Wyrmrider said:
sealed power has the springs
so do others
they should have a dampner
melling/ clevite 2121297
it would be more reliable with modern pistons
Click to expand...
Having trouble locating a source for that Melling number. Most Sealed Power & Melling replacement springs that I can find are for the intake valve only which is way too tall. On the modern pistons: know of any that are low compression that are not made in India or some other such place. Lost trust in Sealed Power, have had some bad parts lately form them, have no idea where their stuff is made.
 
Larry Hutchens said:
Having trouble locating a source for that Melling number. Most Sealed Power & Melling replacement springs that I can find are for the intake valve only which is way too tall. On the modern pistons: know of any that are low compression that are not made in India or some other such place. Lost trust in Sealed Power, have had some bad parts lately form them, have no idea where their stuff is made.
Click to expand...
Use pop up locks if you have to.
Honestly though I would not get hung up on using rotators. Get good valves and hard exhaust seat. The rotators will probably accelerate exh seat wear with today's gas. Lol just get hard seats. Where are you located? Are there wrecking yards near ?
 
MOPAROFFICIAL said:
Use pop up locks if you have to.
Honestly though I would not get hung up on using rotators. Get good valves and hard exhaust seat. The rotators will probably accelerate exh seat wear with today's gas. Lol just get hard seats. Where are you located? Are there wrecking yards near ?
Click to expand...
I've considered that approach but have trouble relying on aftermarket parts, country of origin usually unknown. Other problems: ex valve w/ rotors slightly larger than valves w/o rotors. Hard seats, again country of origin? Another problem can't find a machine shop that I can trust to install them. The head guy I used for a long time has retired. If not done right they can come loose under hard use. Do not have any long term use experience w/ valves such as manley. The Chrysler stuff they put in their truck & industrial engines was quite durable & I have confidence in their product. Live in Okla & there are plenty of yards nearby. The engine I have is in very good shape & was properly cared for all it's life. Now these rotors were used for a long time mostly in the years of unleaded gas & performed quite well. The original heads went about 90K miles w/ minimal wear on the heads. Valves & seats fairly good so I'm going to stick w/ factory stuff as much as possible.
 
Larry Hutchens said:
I've considered that approach but have trouble relying on aftermarket parts, country of origin usually unknown. Other problems: ex valve w/ rotors slightly larger than valves w/o rotors. Hard seats, again country of origin? Another problem can't find a machine shop that I can trust to install them. The head guy I used for a long time has retired. If not done right they can come loose under hard use. Do not have any long term use experience w/ valves such as manley. The Chrysler stuff they put in their truck & industrial engines was quite durable & I have confidence in their product. Live in Okla & there are plenty of yards nearby. The engine I have is in very good shape & was properly cared for all it's life. Now these rotors were used for a long time mostly in the years of unleaded gas & performed quite well. The original heads went about 90K miles w/ minimal wear on the heads. Valves & seats fairly good so I'm going to stick w/ factory stuff as much as possible.
Click to expand...
Shaking my head..is the nicest response I can offer. You sound like you lived under rock or time warped from 1959.

Good luck.
 
MOPAROFFICIAL said:
Shaking my head..is the nicest response I can offer. You sound like you lived under rock or time warped from 1959.

Good luck.
Click to expand...
You must have a lot more confidence in some of that stuff than I do. Most recent things from Sealed power: timing chain tensioner made in Taiwan, double row timing chain made in Taiwan, main bearings for 3.9 V-6 made in Brazil (one shell had trash imbedded in the babbit layer & scratched a freshly ground crank), main bearings made in Mexico, pistons made in India & quality is not that great. Melling: did find a double row timing set USA made but their lifters I got were made in mexico. Ball & roller bearings made in China fail way before they should, probably due to the lack of knowledge of metallurgy. Any time I look for ball bearings I search for Nachi brand or made in Italy, they seem to be of better quality. I'm not alone, a lot of mechanics are constantly complaining about the quality of replacement parts. Get tired of re-doing a job, gets old. A ot of that aftermarket stuff will work just fine in a vintage car that is driven probably 2 or 3 times a month like my Duster. A 1 ton van that will be used on trips is a different story. Haven't done research on valve seats but was discussing valve guides w/ my machine shop & he said that he is having trouble getting units that are made of good material, most are too soft. If you haven't noticed a loss of quality then you haven't been very observant.
 
You have to investigate what you're buying.
Sometimes you have to go to five or six different sites to figure out where something is made or the true spec you just have to shop smart be wise so on and so forth May the force be with you
 
start a new thread
op asked about good made in usa seats, there are others Maartin wells Well-tite etc
we did a lot of testing on propane motors and the then Made in Washington then bought by and now made by Durabond are the best
although I have not tried the copper infused ones- should be safer than berrelium
be prepared for a learning curve on the machinging, cutting oil selection, etc
the electro hardness of late stock hardned heads can be only .050
and using a larger valve to get a new seat i do not recommend on exhausts- works on intakes
 
Larry Hutchens said:
Having trouble locating a source for that Melling number. Most Sealed Power & Melling replacement springs that I can find are for the intake valve only which is way too tall. On the modern pistons: know of any that are low compression that are not made in India or some other such place. Lost trust in Sealed Power, have had some bad parts lately form them, have no idea where their stuff is made.
Click to expand...
Wyrmrider said:
start a new thread
op asked about good made in usa seats, there are others Maartin wells Well-tite etc
we did a lot of testing on propane motors and the then Made in Washington then bought by and now made by Durabond are the best
although I have not tried the copper infused ones- should be safer than berrelium
be prepared for a learning curve on the machinging, cutting oil selection, etc
the electro hardness of late stock hardned heads can be only .050
and using a larger valve to get a new seat i do not recommend on exhausts- works on intakes
Click to expand...
Thanks for the info. I'll talk to my machinist about the duralast units. I'll probably use the heads I have for the short term & build another set to replace them later on. That or I'll try a set of Enginequest heads that are set up for the LA intake manifold. I have used them on 2 other engines w/ very good luck. On the beryllium thing: We were using that stuff at American on the Airbus landing gear & had to use safety gear when machining (masks & special coveralls). Stuff can cause a variety of health issues. Boeing & Douglas used alum-nickel-bronze but Airbus insisted on the Copper Beryllium stuff.
 
Wyrmrider said:
durabond valve seats- the 9000 searies and the new copper embeded ones
Click to expand...
Tried that Meling/Clevite #, turned out to be a Mahle # instead. However both are obsolete numbers. I have a local engine builder shop order a set from someone I haven't heard of, some 3 letter designation. Will find out what they are when they get here. He said that I don't have to buy them if not what I want. There was no pic of them in the catalog so who knows? Again, thanks for the info.
 
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