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Discussion Starter #1
So after tracking my boost issue to the exhaust manifold I'm going to pull the head. Since I have 3 or 4 heads laying around here and my old mans I thought it best to take advantage of the situation and get one cleaned up ready to go on. There's nothing wrong with mine but it seemed like a time saver. While looking through what's there I found a 2.2 head with a flat tappet cam, It's stamped as a 86-87 782 casting, the interesting thing was it's been ported nicely intake and exhaust. I also found a 2.5 T1 roller cam I'd like to swap in for my long duration 87' slipper cam. I have a ported exhaust manifold here as well to throw on.

My questions are as follows;

1) Visually what am I looking for to see if this head is cross drilled as my 87' T1 block is not. It does have the T5 stamp for turbo use.

2) Can I use the 2.5 cam with my 87' square tooth pulley? Will it dial in correctly, or does it need to be offset? I realize I need the roller followers to go with it.

3) In theory less duration at the same lift pushes the power band lower in the rpm range. Am I correct in assuming that the 2.5 roller cam will have better lower and mid range than the 87' slipper cam? I mean the roller has dramatically less friction and a duration 228 vs. the flat-tappet's 240. I'm looking for max power under the curve up to 4k/rpm?
 

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1. you can run a x-drilled head on a non x-drilled block, and vice-versa

2. the common knowledge is that a 'round tooth' cam installed with a 'square tooth' gear will result in 4 degrees retard = move powerband up in RPM;
that is the way I am running.. you may wish to get a adj. cam gear or offset cam keys to adjust the cam timing

IMO every head buildup should include O/S exh. valves, PT lifters, & 3.3 (or aftermarket) conical springs with appropriate retainers
 

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Discussion Starter #4
Excellent, good to know.
I would love to use pt lifters and os valves, but this is a daily and I'm feeling pretty lucky I found a mildly ported head in the graveyard out back. No cracks and it's millable.
quick 3-angle valve job, and see if I can get the shop to back-cut my valves in time and I'm ready to go.

will the cam be retarded 4 crank degrees. I don't have time to ship in offset keys, I guess I'll just have to eye it as best I can.

Thanks for the help all.
 

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further on 1) DDG:
DDG- Turbo heads

"There are a few more curves to throw your way before we move on. All Turbo II & 2.5 Turbo heads are "crossdrilled" for better block cooling (the blocks are crossdrilled as well to match) Later TBI engines have this feature as well (91 and up?) I have had no problems mixing these heads with normal blocks and vice versa. (The normal TII head gasket works fine for this combination)"

Theres a pic of a x-drilled block at DDG
DDG- Turbo shortblock
a x-drilled head will have corresponding holes to mate with the ones in the block ;)
 

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will the cam be retarded 4 crank degrees. I don't have time to ship in offset keys, I guess I'll just have to eye it as best I can.
theres nothing to 'eye'

there is only one way to install a timing belt

and when you use your sq tooth gear on the rd tooth cam, it will be 4 deg retarded (according to common TD knowledge)

unless you have an adj cam gear or offset cam keys
 

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t it will be 4 deg retarded (according to common TD knowledge)
... which is pretty much based on hearsay. Nobody has correctly checked this theory and reported the info.

If the SQTH cam gear on your engine is the one normally used on the turbo engine ... not the special Shelby "carb" engine of the era ... there will be no timing issues. Once again, check it. It's easy to do.

You can not hold one sprocket over another ... of a different family ... and determine timing info. The right way to do this is to install the SQTH sprocket you have on to the camshaft while it's in the head .. @TDC. (marks on the sprocket parallel with the head surface) Remove that sprocket and replace it with the RDTH sprocket ..(or vice versa) without moving the camshaft. You can do this on the engine or off. All you're looking at is the timing position of the camshaft.

If the marks still line up with the heads surface that tells you that the timing between those two sprocket hasn't changed.
If there's a difference .. you'd have to rotate the cam to bring the marks back inline.

What I've found is that cam sprockets #557 and #690 ... both RDTH sprocket are 4* apart from each other.
What I've found is that between #557 (RDTH) and the SQTH sprocket #974, common to the 2.2l engines (turbo and TBI) there is no change in timing. I base this on the method I posted above.

Once again, if you don't have to move the camshaft you haven't change the timing.

According to the info I've seen, that '89 2.5l T1 cam you're going to install is ground identical to the '89 2.2 T2 cams. (in case you weren't sure)
 

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Discussion Starter #8
Wow, good knowledge here.
My engine is an 87' T1 w/ SQTH cam sprocket, I will be re-using this on the 89' 2.5 T1 roller cam when I swap in the new head. I will check the sprocket marks and compare as you recommended. hopefully they place the key-way the same. If they are indeed 4' delta, I can easily "eye" the cam back into a straight up position by adjusting the cam's TDC position vs. the flywheel mark.

Offset keys are more accurate, and an adjustable pulley is easier, but you can advance/retard a cam on these engines without either.
 

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Wow, good knowledge here.
My engine is an 87' T1 w/ SQTH cam sprocket, I will be re-using this on the 89' 2.5 T1 roller cam when I swap in the new head. I will check the sprocket marks and compare as you recommended. hopefully they place the key-way the same. If they are indeed 4' delta, I can easily "eye" the cam back into a straight up position by adjusting the cam's TDC position vs. the flywheel mark.

Offset keys are more accurate, and an adjustable pulley is easier, but you can advance/retard a cam on these engines without either.
Thats not how it works.
 

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Discussion Starter #12
I guess its possible if u ran w/o a key ...

anyone ever done it ?

What, run a cam advanced or retarded without an offset key?
I have on several occasions, not without success either.

I'd still like to hear how my logic is flawed, am I misunderstanding the difference in the sprockets? What is it that "doesn't work that way"?

There is a procedure for adv/ret a cam without keys on allpar.
Aren't the different sprockets just marked for btdc differently?
 

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What, run a cam advanced or retarded without an offset key?
I have on several occasions, not without success either.

I'd still like to hear how my logic is flawed, am I misunderstanding the difference in the sprockets? What is it that "doesn't work that way"?

There is a procedure for adv/ret a cam without keys on allpar.
Aren't the different sprockets just marked for btdc differently?
wow.

OK, then, i guess if u can run w/o a key then:
there isnt only one way to do cam swap

if puppet is right and theres no centerline difference between 88+ & 87- cams, then u dont need to do anything, install straight up.

then, go ahead and play with a little retard, then a little advance ..
see which one you like ... let us know !!
 

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Discussion Starter #14
mopar records show there both 110 centerline.
I'll let you know how it goes.
I tried adv and ret my slipper cam this way and even with the long 240 duration found that straight up made the most power up to 4k. I'm hoping the 228 duration roller will be like advancing the slipper cam without the power loss.

Cheers, and thanks for all the help.
 

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Whatever you do dont EVER try an run an engine with out keyways.

Doing it with one of ours will only result in the gear spinning and gulling it up and timing issues.

BUT on an interference engine say bye-bye motor, cause it will be munching on your valves in seconds.




And I'd really like a detailed explanation on how you think are changing the cam timing without changing:
A)relationship of the keyways on the cam and gear
B)the relationship of the keyway to the teeth.
Either you have an adjustable gear, offset keyways, or are cutting and welding the gear. If not youarent, then you arent changing anything. Unless you are talking about moving the cam gear a full tooth either way, which is stupid in its own sense.


Unless of course you are confusing the ignition timing with cam timing.
 

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Discussion Starter #17
Whatever you do dont EVER try an run an engine with out keyways.

Doing it with one of ours will only result in the gear spinning and gulling it up and timing issues.

BUT on an interference engine say bye-bye motor, cause it will be munching on your valves in seconds.




And I'd really like a detailed explanation on how you think are changing the cam timing without changing:
A)relationship of the keyways on the cam and gear
B)the relationship of the keyway to the teeth.
Either you have an adjustable gear, offset keyways, or are cutting and welding the gear. If not youarent, then you arent changing anything. Unless you are talking about moving the cam gear a full tooth either way, which is stupid in its own sense.


Unless of course you are confusing the ignition timing with cam timing.
Okay, I'm going to politely ask you not to respond to my posts. This is the third time you've felt the need to reply to a thread I started with critical or useless information, I've indulged this in an effort to be open minded to the possibility that despite how you come off you have something helpful to say. Beyond that you feel the need to speak to me like I'm an idiot. So from now on when I'm wasting you're valuable time with my nonsensical questions feel free to skip being a dick and just don't reply.

For the record advancing or retarding a cam without the use of offset keys or an adjustable sprocket has been done commonly for the last 60 years. You have google try using it before you put your foot in your mouth.

Secondly if you think doing so is stupid, that's fine it's called an opinion and anyone can tell you that everyone's got one. However that doesn't make it so. First time I asked about advancing a cam this way I received help from several people who have done so with out issue, NAJ, Midnighttoker, roachjuice, etc. They offered useful information, negative and positive.
I used that information to make an educated decision, that's how this works.

Would you call them stupid for doing so?
Because that's what your doing when write things like that.
What about the man who took the time to write this;
Setting advanced cam timing on the Chrysler - Dodge - Plymouth 2.2 and 2.5 liter engine ?
Is he stupid too?

Like I said before, keys are more accurate, an adjustable sprocket is easier, but it can be done without them.

The next time you want to pick an argument or talk down to someone, do us all a favor and do so somewhere else.

The people here like cars, not drama.

That being said I apologize to anyone else who read this.
I had to say something, every man's got a point.
 

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ok man I read the site you posted. and it is telling you to move the cam 1 full tooth, it allso said that that will result in 9* adv while this is true if you are thinking only of the cam but remember that the cam moves twice as the crank moves once that means that 9* of cam rotation makes 18* of crank rotation.
any time you are changing the timing of the cam the adv,ret is allways shown in crank* of rotation. so when you move the cam 1 tooth you will be changing the timing by 18*. now while our tds will run this way it is not good for them do your self a flavor and just set it up the way you should and not play with the cam timing if you dont have a offset key of adjustable sproket.
 

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Discussion Starter #19
No I wouldn't advocate moving an entire tooth either.
I was trying to illustrate the "how to" for this.
You can also remove the timing belt completely and adjust the cam timing in crank degree's using the flywheel mark.
It's not nearly as accurate as an offset key, but you can feel the slop in every cam and with careful attention to detail 4' crank time is not a tough adjustment IMHO.
 

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if puppet is right and theres no centerline difference between 88+ & 87- cams, then u dont need to do anything, install straight up.
Hold on Dave ... not what I wrote. What I wrote was that there is no difference between the cam sprockets ... #974 SQTH vs #557 RDTH. Cams ADV/RET is a different matter.
 
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