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1987 GLHS 0564
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Discussion Starter · #1 · (Edited)
So I pulled the engine out my 87 GLHS so i could replace the clutch, address oil leaks, clean engine bay, and just a general look over of the parts while on a stand.

Knew previous owner replaced the head due to an overheating event, but he knew nothing about the valves, cam, etc. I pulled the head as I found out this 782 Chrysler head was a CD head, but no TS stamped on it.

Today I put a micrometer to the intake and exhaust lobes and only measured lift. Got my numbers but they are no where near anything on Donvans website. I am assuming his lift number either 1. Are from cam center line inwhich I would need to measure cam lobe base diameter and divide by two and add to the lift I saw with the indicator, or 2. His lift numbers are measured at the valve face.


EDIT: Just realized I did not multiply times rocker arm ratio which I am not sure that that is on a roller setup. Seems roughly 1.7?


Anyhow, when I removed the cam caps so i could pull the followers I was greeted with a destroyed cam and head. Mind you this reman head was installed in 2019. No idea how many miles the previous owner put on this head, but I have put 2k on the car after I bought it. Weird thing is no signs of garbage in the cap bearing area to account for the damage. Suppose it's possible the head was put on with the head and cam looking like this. Unfortunately inalready drained the oil and dumped it at a recycle center so I cannot filter it for crud. I will say that last year when i drained the oil I was not greeted with a gold mine in the oil pan.

Tomorrow I plan to pull the oil pan so I can pull the main caps and inspect those bearings along with the crank. I am also going to pulled the rod caps and look at those bearings. I figure worst case I will need a new crank and all new bearings for the short block. I think I may also try cutting the oil filter open and see if i can see anything in it. Cylinder walls looked good, but I have not measured them. Right after I bought the car I did a compression test and when cold all were between 125 and 132 I believe and when got 135 to 142. I posted the results in this forum somewhere.

I am trying to look at this in a positive light and glad I caught it now with the engine removed vs a catastrophic failure while on the road.

Btw already ordered a replacement head.
Font Gas Metal Auto part Engineering
 

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So I pulled the engine out my 87 GLHS so i could replace the clutch, address oil leaks, clean engine bay, and just a general look over of the parts while on a stand.

Knew previous owner replaced the head due to an overheating event, but he knew nothing about the valves, cam, etc. I pulled the head as I found out this 782 Chrysler head was a CD head, but no TS stamped on it.

Today I put a micrometer to the intake and exhaust lobes and only measured lift. Got my numbers but they are no where near anything on Donvans website. I am assuming his lift number either 1. Are from cam center line inwhich I would need to measure cam lobe base diameter and divide by two and add to the lift I saw with the indicator, or 2. His lift numbers are measured at the valve face.


EDIT: Just realized I did not multiply times rocker arm ratio which I am not sure that that is on a roller setup. Seems roughly 1.7?


Anyhow, when I removed the cam caps so i could pull the followers I was greeted with a destroyed cam and head. Mind you this reman head was installed in 2019. No idea how many miles the previous owner put on this head, but I have put 2k on the car after I bought it. Weird thing is no signs of garbage in the cap bearing area to account for the damage. Suppose it's possible the head was put on with the head and cam looking like this. Unfortunately inalready drained the oil and dumped it at a recycle center so I cannot filter it for crud. I will say that last year when i drained the oil I was not greeted with a gold mine in the oil pan.

Tomorrow I plan to pull the oil pan so I can pull the main caps and inspect those bearings along with the crank. I am also going to pulled the rod caps and look at those bearings. I figure worst case I will need a new crank and all new bearings for the short block. I think I may also try cutting the oil filter open and see if i can see anything in it. Cylinder walls looked good, but I have not measured them. Right after I bought the car I did a compression test and when cold all were between 125 and 132 I believe and when got 135 to 142. I posted the results in this forum somewhere.

I am trying to look at this in a positive light and glad I caught it now with the engine removed vs a catastrophic failure while on the road.

Btw already ordered a replacement head. View attachment 283315
I would strip the head of all parts then practice porting on it since it's scrap anyways.
 

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1987 GLHS 0564
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Discussion Starter · #3 ·
I would strip the head of all parts then practice porting on it since it's scrap anyways.

Not sure it's scrap just yet. I have a buddy who bought all the tooling to line hone the journals, taper the journals, and then use a bearings just like on the rods and crank.

But otherwise, yes a scrap head to tinker with.
 

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1987 GLHS 0564
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Discussion Starter · #4 ·
Decided to pull a couple lash adjusters out and found spacers/shims under the lash adjusters! Mind.you this head had roller followers installed. No idea what these lash adjusters are from as previous owner bought the head previously built and simply installed it.

Also discovered serious side wear in the lash adjuster holes. Guessing this was the source of what damaged the cam journals.

I did pull the main bearings along wirh the rod bearings and all looked good as did their respective journals.

Just waiting for my replacement head to arrive from TD Parts.
 

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1984 Dodge Rampage Turbo
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If there are spacers under the adjusters, they are probably PT/2.4 adjusters. This is a common upgrade done to heads. There is a thread on it here.
 
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The PT lash adjusters (the base of the adjuster, not the plunger) is about .125" shorter than a normal 2.2 lash adjuster. Since the cylinder head was replaced, it is quite possible that the head was mediablasted. Not cleaning good enough combined with NOT removing all plugs (oil passage and coolant core plugs) will trap mediablast material in the head. Always run a brush through the oil passage from one end of head through the other end. At startup, the blasted material in the oil passage will wipe out the camshaft and journal bearings almost instantly. That would be my guess what happened to the head. Seen it many,many, times before. People just cut corners... Often when this happens, the turbo suffers a similar fate, and fails shortly after startup.
I have no problems media blasting the head, but it MUST be cleaned perfectly. After all, the head was cast, and it had sand everywhere inside and out when cast, Chrysler removed it all, so why couldn't that be repeated? I beadblast virtually everyone I disassemble and port, and have never had an issue with doing so. The cylinder head can never be too clean...
You can check for a shortened base circle on the camshaft to rule out a reground camshaft. The base circle should be almost exactly 1.400". Anything less than 1.380" suggests the camshaft is reground and typically uses shims under the lash adjusters to compensate for the decreased base circle the camshaft now has. That is typically done to make a larger duration and higher lift profile on the camshaft. How thick were the shims under the lash caps? Steel, stainless?
Yes, as stated, you measure base circle and then high point of lobe. Subtract the two to attain lobe lift. This should be around .245" then multiply by 1.75"-1.77" to find camshaft lift. All stock rollers should be around .432-.433" lift. Sliders come in at .430".
 

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1987 GLHS 0564
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782 Posts
Discussion Starter · #8 ·
The PT lash adjusters (the base of the adjuster, not the plunger) is about .125" shorter than a normal 2.2 lash adjuster. Since the cylinder head was replaced, it is quite possible that the head was mediablasted. Not cleaning good enough combined with NOT removing all plugs (oil passage and coolant core plugs) will trap mediablast material in the head. Always run a brush through the oil passage from one end of head through the other end. At startup, the blasted material in the oil passage will wipe out the camshaft and journal bearings almost instantly. That would be my guess what happened to the head. Seen it many,many, times before. People just cut corners... Often when this happens, the turbo suffers a similar fate, and fails shortly after startup.
I have no problems media blasting the head, but it MUST be cleaned perfectly. After all, the head was cast, and it had sand everywhere inside and out when cast, Chrysler removed it all, so why couldn't that be repeated? I beadblast virtually everyone I disassemble and port, and have never had an issue with doing so. The cylinder head can never be too clean...
You can check for a shortened base circle on the camshaft to rule out a reground camshaft. The base circle should be almost exactly 1.400". Anything less than 1.380" suggests the camshaft is reground and typically uses shims under the lash adjusters to compensate for the decreased base circle the camshaft now has. That is typically done to make a larger duration and higher lift profile on the camshaft. How thick were the shims under the lash caps? Steel, stainless?
Yes, as stated, you measure base circle and then high point of lobe. Subtract the two to attain lobe lift. This should be around .245" then multiply by 1.75"-1.77" to find camshaft lift. All stock rollers should be around .432-.433" lift. Sliders come in at .430".
Thank you Todd! This gives me something to do until the new head assembly arrives.

Sorry about the below grid as I have no idea what hit to put it there or how to remove it.

 

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pt lash adjusters are as said shorter than the o-s's ..but if you don't have anything in hand to compare it to..
we use pt lifters for a reason..they have a wee little bleed hole to let trapped air out
the regular 2.2 lifters never had that hole

now ,to add. the spacer accommodates the shorter lifter and everything works out ok dokey
but
if
you buy a regrind camshaft..
you cannot use the pt lifters any more as they need to be raised even further and this then exposes that bleed hole above the lifter bore
..so the whole deal won't work..
regrinds need stock height lifters
..so I've benn told
 
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