Degree an installed/unknown camshaft

[PRHeads]

Using your .050 numbers I get 236/245-107.25 in at 91.

27+180+29 = 236
66+180-1= 245

236/2=118.... 118-27=91
245/2= 122.5.... 122.5+1 =123.5
123.5+91= 214.5 ...... 214.5/2= 107.25

The cam is advanced approximately one tooth, provided the degree wheel and pointer were zeroed out correctly at the beginning.

It’s more than likely one of the Hughes cams from the Engle days.

If the cam comes out, I’ll be surprised if it’s not a Hughes HE3844BL, or the Engle equivalent.

Just sayin’

 

[Wietse]

Just sayin’

I did think about it to read back as i remembered someone mentioned a Hughes camshaft but i forgot to look for it.

Good aim my friend!

 

[Wietse]

I have redone 2 rounds on each lobe with the following:

Exhaust valve @ .050"
Open: 50* BBDC (53*)
Close: 13* ATDC (11*)
Centerline: 108*

@ .008"
Open: 72* BBDC
Close: 39* ATDC
Duration @ .008": 291* (291*)

Intake valve @ .050"
Open: 13* BTDC (14*)
Close: 44* ABDC (44*)
Centerline: 106*

@ .008"
Open: 36* BTDC
Close: 69* ABDC
Duration @ .008": 285* (283*)

(Between brackets is as per cam specs.)

I guess measurement errors again, i cannot see how or what adjustment could rectify the differences between my measurement and the cam specs mentioned before.

 

[Wietse]

So, did this changing 1 tooth of the cam sprocket just made a difference of 14* crank rotation for the valve events?
Guess so right? It is 7.2* for the camshaft, so 14* for the crank.
Now why did they advance it 14*? Does that bring the power band of the cam to lower rpm?

Edit: I looked on the web for a full spec cam card for this camshaft but i did not find any.
Any idea where to find? Or should i contact Hughes and ask if they can provide me one?

 

[wyrmrider]

Making some progress but you scared me thinking you timed a tooth at a time you can really bend things
now
compare your .050 measurements from the data from that cam you can get from hughes post it up recommended intake lobe center,
and
go to the hughes obsolete cams page on their website and see if it's there - report back
most likely an Engle so go to Engle website and find cam with same specs
you will find the seat timing at .008 there
now to save time just work with the intake lobe center
down .050 each side of the nose and report where the mid point is
To keep it simple if Hughes says the cam is on a 110 LCA then straight up would be with the Intake ICL at 110 ATDC
+4 would be 106
-4 would be 114
but if the cam is ground with +4 built in
the straight up circle on the crank gear would be 106 on your degree wheel (midpoint of checking cam nose on both sides)
+4 would be 102
-4 would be 110
so where are you?


good read
http://nastyz28.com/threads/what-are-the-symptons-of-a-cam-off-a-tooth.164431/

the .050 timing does not help AJ with his dynamic compression analysis

 

[Wietse]

What i got so far on data of this cam is in post #115.
I will try to find a spec card from Engle now and take the Intake Centerline as you described, i forgot to check that one.

Edit:
Ok, i checked and currently the Intake centerline is at 106* ATDC.
Now need to find the LCA as per Hughes....

 

[Wietse]

Well, seems like the internet does not know the LCA of this camshaft....

Also Engle their website does not provide any information of any kind about any cam.

 

[AJ/FormS]

Well, seems like the internet does not know the LCA of this camshaft....

Also Engle their website does not provide any information of any kind about any cam.

I do,lol. or at least I can figure it out.
Working from your numbers;
Intake lobe is 36+69+180=285 @.008, and 285/2 less 36= 106.5 installed CL of the intake valve
Exhaust lobe; [email protected], and 291/2 less 39=106.5 the installed centerline of the exhaust valve
106.5 plus 106.5 divided by 2= 106.5 the Lobe displacement angle; using your numbers. And you are in "straight up", at zero advance; so, time for a compression test. I'm very excited,lol.

 

[AJ/FormS]

So it's a Hughe Engines HE3844 BL camshaft.

Now; working from this figure
[email protected], and 238/2 less14=105 the installed centerline of the intake lobe
[email protected], and 244/2 less11=111 the installed centerline of the exhaust
105 plus 111 divided by 2 = 108 the Lobe Displacement angle. And in this case they want it in at 105 which would be 3 degrees advanced.

 

[AJ/FormS]

now; your numbers are indicating straight up despite them being different than the card. If I assume your errors are equally divided between the intake and exhaust lobes, Then you are in fact straight up.
And I would now roll it over gently looking for PV interference and if none found, then the next thing I would do is the compression test.
And if the new numbers allow it, then.... THEN you can think about advancing that brute.
In any case; when it's all over,I would still do an accurate PV measurement, cuz if you ever over-rev it, and the lifters pump up, you just gotta allow for the worst case. And over-rev does not always mean some arbitrary RPM number; no, over rev is when the springs fail to control the valves, and the lifters pump up, and the valves get mangled, possibly the valve heads break off and destroy almost everything but the crank and rods. That would be a catastrophic failure. Usually if that happens, it takes out the head, the piston, and the block... at least, and then some other junk; Very expensive.

What I mean to say is with a 3.31 stroke SBM, the max piston speed is somewhere around 7000 or higher if I recall. So you might set your rev-limiter to 6900.
But if this is a smogger teen, the valve springs are good to about 4500, and valve float could begin at 4501. Now you might thing with the pistons down so far in this instance, and the valves would never get down there. But I think you would be wrong,lol. Because I have taken a couple of those apart, that showed clear evidence of contact.

 

[Wietse]

So, now being @ 106* it's at 2* advanced. (maybe due to the chain there is a slight difference?)
But if it came back from so much (14*) advance already, would the PV clearance still be an issue to consider?
Guess now the danger is coming from the other side.
And, having retarded it now by aligning the sprockets, and having the cam "straight up" what is the difference in the engine's behaviour compared to before?
I mean, if putting it "straight up" does not give any advantages/improvements i could avoid the potential danger of smashing the valves and put it back as it was? (we know this worked)
When cranking i will build up oil pressure, the lifters will go stiff and if there is an interference i will be screwed.
Cranking by hand would never warn me for the potential.

 

[AJ/FormS]

So, now being @ 106* it's at 2* advanced. (maybe due to the chain there is a slight difference?)
But if it came back from so much (14*) advance already, would the PV clearance still be an issue to consider?
Guess now the danger is coming from the other side.
And, having retarded it now by aligning the sprockets, and having the cam "straight up" what is the difference in the engine's behaviour compared to before?
I mean, if putting it "straight up" does not give any advantages/improvements i could avoid the potential danger of smashing the valves and put it back as it was? (we know this worked)
When cranking i will build up oil pressure, the lifters will go stiff and if there is an interference i will be screwed.
Cranking by hand would never warn me for the potential.

No, no, no, no, and no
Firstly; you don't know where the previous assembler set the PV clearance at; I mean he screwed up the basic cam install, so you kindof have to wonder what else.
From 14 advanced to zero advance will move the power peak up to where it belongs, which being about 50rpm per degree so perhaps 700rpm higher. The bottom will be softened to something less aggressive than it was, and the cylinder pressure is the big thing, will or may return to something more sane than 200psi, we are looking for 165 or less to run your gas..
At cranking speed your lifters will need a lotta, lotta cranking to "pump up". With adjustable valve gear, you will install some checking springs and reduce the lifter preload to zero,and begin with pumped up lifters; then go hunting for the crank position that nets the minimum PV clearance. From that closest to the piston clearance, you will check the spec book (IDK anything about BBs) to see if you still have enough PV clearance for growth at temp and rpm, and how much lifter preload you can't run.
It behooves you to do this no matter what, cuz how can you trust the previous assemblers work?
If you don't check it, and somehow you destroy your engine, you better not say anything bad about the previous builder.

 

[Wietse]

Ok, now i am scared to crank it.
I already rotated several times by hand and did not notice any tight spots.

And if the new numbers allow it, then.... THEN you can think about advancing that brute.

I just retarded it, should i put it back as it was? Guess what i did is taking some horse power/torque away from lower rpm.
But did this gain anything in driveability? The swap of 1 tooth on the cam sprocket equals 7.2* on the cam, so 14* on the crank right? To me, thats a lot of advance taken away.

What's a smogger teen? lol
I think that when installing this camshaft they did think about a set of springs to match it right?
Otherwise they have been playing with fire from day 1.

 

[AJ/FormS]

Cranking by hand would never warn me for the potential.

Oh yes it will; there is no mistaking it when the valve is contacting the piston. Everything comes to a halt.

 

[AJ/FormS]

comments in the quote

Ok, now i am scared to crank it.
I already rotated several times by hand and did not notice any tight spots. Excellent
I just retarded it, should i put it back as it was? NO!
Guess what i did is taking some horse power/torque away from lower rpm. You had waaaay too much anyway cuz you couldn't even run the Vcan
But did this gain anything in driveability? Big time yes. the thing about the all-in mechanical timing is this; It tries to make sure the engine has the right amount of timing at WOT and WOT only. The idle timing falls out with the Transfer slot sync. From idle to all-in, the timing has to be reduced so that if you decide to floor it at 1200 rpm, the skirts don't all fall into the pan. Without the Vcan; at every and all other situations, your engine NEVER has the correct amount of timing. NEVER. That is what the Vcan is there for, to make up the difference between what the mechanical is doing, and what the engine is wanting at every conceivable load-setting and rpm; between idle and all-in. Since with the over-advanced cam situation you couldn't even run the Vcan without immediate detonation, your engine never had a chance to show you what it could do at Part Throttle; am I wrong?
With the pressure now reduced to normal, you can bring in the missing timing with the Vcan, and IMO you will have a far better performing combo, than the one that was timing handicapped. and over pressured.
The swap of 1 tooth on the cam sprocket equals 7.2* on the cam, so 14* on the crank right? To me, thats a lot of advance taken away. Not taken away; it was waaay too much to start with. Now it is restored to normal.The degree wheel tells the story.

What's a smogger teen? lol Low-compression 318 from 1972 and up, usually advertised as 8/1. pistons are often .057 down in the holes. And lifts are puny; .391 or something, I forget.
I think that when installing this camshaft they did think about a set of springs to match it right?Otherwise they have been playing with fire from day 1. One would hope so, but hope is all you got.

 

[Wietse]

At cranking speed your lifters will need a lotta, lotta cranking to "pump up". With adjustable valve gear, you will install some checking springs and reduce the lifter preload to zero,and begin with pumped up lifters; then go hunting for the crank position that nets the minimum PV clearance. From that closest to the piston clearance, you will check the spec book (IDK anything about BBs) to see if you still have enough PV clearance for growth at temp and rpm, and how much lifter preload you can't run.

Wow, that's going to be interesting. I do understand the need of doing the PV clearance but i will be in the dark with that job.
So with the checking springs installed with "0" pre-load is going to be the travel reference for the valve.
But how to know the piston height?
I have no idea of how much it is below the deck, even, or above for that matter.
With the compression being on the high side the pistons will be up high i guess.

Edit: Guess i figured it out already, when bringing the piston up you can check anytime the PV clearance by pushing down on the rocker and measure how much gap is still between them.
Then i should be able to find the specific crank degree where there is the smallest clearance and how much this clearance is.
Need to go and get some tools ordered for that.
Would it be beneficial to know the valve spring pressure as well?
Then i will find a tool also to check the compression force.

Btw, thank you guys so much for al this. I thought i already figured out some about this stuff but it seems i still have a long way to go.
Really appreciate the help from you!

 

[miller]

I do understand the need of doing the PV clearance but i will be in the dark with that job.

Do yourself a favor...and make it easy on yourself!
Hell, it's only parts and pieces. Get a piece of 0.100" wire. Your gonna get down and dirty, caveman style. That piece of wire will be your gauge, minimum P/V clearance. I'd suggest doing at least one piston, each side. I've done this plenty of times, to be sure of the clearance.
Valve covers off, so you can watch the valve movement. #1 until the piston is on stroke, intake valve fully open. Through the spark plug hole, make a wipe with that wire, between the valve head, and piston. If it goes, your good. Same thing on the exhaust valve.

It's worked for me. I say 0.100, because through all the RPM ranges, that much you can be sure will be enough, to not tear anything up.

 

[Wietse]

I will order some checking springs to do this, with an air supply i can keep the valves up and remove the springs and install the others, then will be just cranking the piston up from 90 BTDC with 5* increments for a start and see how much is left between piston and valve by pushing the valve down manually to see if it is close.
Then i can determine exactly how much clearance is there, i also need to consider lifter pre-load.

Just wondering if spring tension is something to check for any reference/adjustments or so, while i have them off it is best time to check as well.

 

[wyrmrider]

I do not think you have a PV problem or you would have bent something by now
glad you have it installed at a reasonable position
Those numbers advance retard numbers I posted were for 110LCA I think you cam is 108 so you have to adjust
now that you have the .050 timing from Hughes you can time that way
I just do not use .050 for unknown cams and use the nose measurement instead
not to confuse but if the cam is asymmetrical then the nose center is not in line with the .050 so it is useful to know which way the cam grinder specified the timing
Engle says to advance the cam till it pings then back it off
really the old school way of doing it
should work like a DC 284
still have not had time to read all the posts but in at 108 ATDC should be a good place to start
Thanks AJ
and once you get AJ's final numbers someone mentioned Yellow Rose or YR as a good help in tuning a high compression build (if you really are high_
I concur

 

[Wietse]

Most likely the PV clearance will be ok indeed, but i want to make 100% sure, anyway this summer of driving went down the drain anyway so no rush to get it done in a hurry.
I will just take my time and learn as much as i can from it and in the meantime make sure all is well, so once back in the car i do not have to screw around with it again.

Just figured that the checking springs come in smaller diameters than the normal valve springs, which are 1.5" O.D. i believe.
What size fits over the valve stem seals? i found a set at shop in Germany, 2" height and .0875" diameter.
https://www.moparshop.de/en/Online-Store/Tools-Shop-Equipment/43356/Valve-Check-Springs-pair?c=595

For a valve spring compressor i found this one: (local) https://www.autogereedschap.com/a-3.../klepverenlichter-enkelzijdig-heavy-duty-bgs/

For heavy duty (double) spring type, should be ok to use right?

Today i was a day on the road so no time to continue but tomorrow i will build the valve train back, close my eyes and crank the engine for a compression test.