View Full Version : compression testing info needed 2004 Optimizer 6500
Aftermath
03-02-2016, 20:39
So I bought an Optimizer 6500 long block with the heads off, last Saturday. The last owner said that it lost compression on both sides of the block so he decided to part it out. 60k miles since complete build. He said the head gaskets looked good when he pulled the heads. No scarring in the cylinder walls and can still see the honing markings, cam lobes and lifters look good. I'm going to flip the heads upside down and pour gas on top of the valves to see if there is any leaking. If no leaking, then I may bolt the heads back on and do a compression test. Any advice and all information is greatly appreciated. Thanks in advance !!
LOST COMPRESSION ON BOTH SIDES OF THE BLOCK ???
Interesting concept.
Was there any mention of which cylinders??
There has to be a real good reason to lose compression, and to lose it across the board is pretty vague.
Your description of the bores and such sounds like things are in good shape.
Have you pulled the pan and done a recon in there ???
Might be a wise idea to have a peek, look at some bearings.
With it out on a stand it takes little time to do.
Cover all your bases.
If it all looks good down under then button it up and proceed as you lined out.
Oil the cylinders good before bolting the top on.
At good cranking speed these engines should be able to show 360+ psi after several "puffs" and likely over 400 psi
Losing all compression is ????????????????????
Unless the thing lost oil pressure and the lifters collapsed.
Just remember that these engines use TTY head bolts (One use then toss)
Good luck and keep us in the loop.
john8662
03-03-2016, 08:39
Was this an engine out of Florida?
Aftermath
03-03-2016, 11:53
Was this an engine out of Florida?
Yes, Jacksonville
john8662
03-03-2016, 15:41
Was that Bobbie's engine?
If so, this is really not the place to be asking about how to repair it.
This engine needs to be taken to a machine shop and investigated. The heads need examined as we as all the other intricate details of this engine. It had issues that are not known that will take some good digging.
Way outside of the scope of what can be talked about here.
There is another post on another forum about it where you can see some discussions about it...
J
Aftermath
03-03-2016, 16:41
Was that Bobbie's engine?
If so, this is really not the place to be asking about how to repair it.
This engine needs to be taken to a machine shop and investigated. The heads need examined as we as all the other intricate details of this engine. It had issues that are not known that will take some good digging.
Way outside of the scope of what can be talked about here.
There is another post on another forum about it where you can see some discussions about it...
J
I guess it's the same engine, but the particulars shouldn't change, "compression or no compression". Rotating assembly looks fine
Was that Bobbie's engine?
If so, this is really not the place to be asking about how to repair it.
This engine needs to be taken to a machine shop and investigated. The heads need examined as we as all the other intricate details of this engine. It had issues that are not known that will take some good digging.
Way outside of the scope of what can be talked about here.
There is another post on another forum about it where you can see some discussions about it...
J
Is there some particular reason why it should not be discussed here? It could be a learning experience for us.
Aftermath
03-03-2016, 17:26
I read through the blog completely on the other site and it details and discusses the complete build. He ran this engine successfully for 60k miles before the compression issue. So it seems that it IS something that should be discussed on this forum. This should, and hopefully, be an easy fix. Crossing my fingers. I'll keep you posted on what I find. Thanks
Hmmmmm
Is there a politically charged (controversial) issue with this engine ???
Lets dig into the beast and see what shakes out.
I for one am curious ???
Always up for a good challenge :D
Just sayin.
Aftermath
03-04-2016, 12:09
According to Bobbie, before he disassembled the engine:
1-425 psi
3-125
5-275
7-100
2-400
4-200
6-450
8-200
Very strange spread on the comp ###
My suggestion, and if I were doing this thing, Yank the pan, mark the rod caps if not already done and yank the pistons out and have a peek at the rings.
Something very strange going on in there.
Get that beast torn down to bare bones and snoop it out carefully.
Stuck/broken rings ???
Stories abound when it comes to used anything, and the 6.5 diesels always seem to have a large amount of baggage.
Good luck
Keep us in the loop
Robyn
Too bad (apparently) no one did a leak-down test before ripping it apart.
IF those compression numbers are valid, and since nobody here can prove anything (including the new owner) the only thing to do is rip the sucker down to bare bones.
I am going to toss out a hypothesis, and that is with the reported 60 K miles on the engine, and depending on a few factors, the oil used could be something.
I have seen stuck rings in these things due to carbon from using the wrong oil.
Normally it takes longer than 60 K to see that.
The other possibility is broken rings.
Depending on how much attention to details were paid, possibly the rings did not have enough end gap and at one time or another the engine was WARMED up real good and caused as failure.
Normally when rings bind and fail there will be cylinder wall damage.
The current report is that the walls show cross hatch and look fine ???????
Another long shot is a wash down of the cylinders due to somebody doing ????
Years ago, many years ago when I was a young student of mechanics, I worked for a Chrysler garage.
This was 1969- 1972 in that era.
The big mopar V8's could lose compression if one of a couple things happened.
The engine would be running fine and then would not start.
The thing would spin over and act real strange like there was no compression.
Indeed that was it.
This could be caused by a cold flooding condition (real rich choke setting and the thing died)
Certainly not in a diesel.
There were other conditions such as a hard hot run and shutting down then sitting a few days, then nothing.
We were briefed on this in tech school, but I had never seen it in person.
A few years later (later 70's early 80's) my father owned a big Chrysler with the 383 of late 60's vintage, and one day he drove in and shut it off and it did the "Dieseling thing" that was common with the older high compression engines of that era.
It bucked and snorted and rumbled for quite a while then stopped.
He came out later to go to town and the rig would not start, nothing but spin lazily.
I looked it over and could find nothing obviously wrong with it.
Then I remembered the tech school lecture on the loss of compression.
We checked the compression and found nearly nothing in any cylinder.
AH HAH.
Squirted oil in all the plug holes, spun the beast over well, reinstalled the plugs and Varooom, started right up and ran fine.
PROBLEM
The issue according to the service bulletin was an issue with the rings that were used and the fact that they did not mate well with the cylinder wall.
Basically the rings did not hold small amounts of oil between the ring face and the cyl wall.
The rings were Chrome and the cylinder walls were waaaaaaay tooooo smooth.
The "patch" was an oil additive they came up with that helped.
The other fix was to re-ring the engine, but that was not done unless the problem was chronic.
Dads old mopar never did that again.
I told him to shut it off in Drive to help stop the dieseling issue.
OK
BACK TO THE PRESENT
There certainly could be a ring issue, as in the type used and the surface finish of the rings vs the cyl wall.
The 6.5 normally uses a moly faced top ring, a cast iron second ring and chrome railed oil rings.
The military used chrome top rings in the HMMWV to aid in longevity due to the dirty environments.
The moly rings (face) when looked at under a magnification have all sorts of little od shaped pockets that retain oil to lubricated and seal the ring to cyl wall.
Bottom line
Yank it all the way down and carefully scrutinize the rings and see waaasssssup in there.
I really don't think that there is anything seriously wrong (read this as damaged)
IT NEEDS TO COME APART, and the "I wonder whats" really mean nothing until then.
Sitting here sucking on the second cup of coffee, and ?????????????????
Did somebody run the thing out of fuel and hose it good with Ma Startly (ether) trying to get it going ????
Aftermath
03-06-2016, 14:42
Okay so I did the gas seapage test and all failed but 1. So I started disassembling the head/valves and found a boken spring and tons of carbon/grime buidup between the valves and seats. For the cylinders to look so good, I'm assuming that I found the problem. I'm going to clean, check/grind the valves, replace the spring, new seals etc. put her back together and compression test.
Get some pix of the heads and such and post.
Be good to see them
Robyn
Aftermath
03-06-2016, 16:07
Broken spring
That's ugly
Get some pix of the valve seats and the back of the valves.
Okay so I did the gas seapage test and all failed but 1.
I hope that one matches with a hole that had decent compression...
Would be interesting to know the entire story about this engine, but that's not likely forthcoming.
Anyway, we will do what we can to help get this project back on an even keel.
I still think there is something hinky with the rings and would yank the slugs out to be sure all is well.
Aftermath
03-07-2016, 11:33
JohnC: After the gas test, #1 cylinder exhaust valve seemed to be sealed. The only sealed valve in both heads, the rest leaked.
Robyn: I will post the cylinder psi after the valve grind, if they are low, then I'll pull the pistons and do all the measuring. Again, cylinder walls look very good with minimal wear.
You've been very helpful. I'm extremely thankful!
Chris
No problemo
Just like to help if possible.
Good luck
a5150nut
03-07-2016, 17:42
JohnC: After the gas test, #1 cylinder exhaust valve seemed to be sealed. The only sealed valve in both heads, the rest leaked.
Robyn: I will post the cylinder psi after the valve grind, if they are low, then I'll pull the pistons and do all the measuring. Again, cylinder walls look very good with minimal wear.
So you think it looks good enough to risk a set of head gaskets and bolts plus all that labor again? Pulling the slugs would be so much easier now and you would know for sure.
Just thinking out loud. . .
I AGREE 100%
It's out and easy to get to.
The gaskets and bolts are a one time use item.
Once the bolts have been torqued to spec they are done and can't be reused.
Sure would be good to check things out, including the bearings, then button it up and be good to go.
The bolts are not super cheap either.
Use only FELPRO GASKETS AND BOLT SETS.
These have proven to be the best choice.
OH BTW
Just an FYI
Be sure the push rods are inserted in with the painted end or the copper colored ball to the rockers
If these are installed wrong they will not last.
Only the copper colored ball end is hard and if they are put in wrong they wear really quick.
Good luck
Aftermath
03-07-2016, 21:37
ARP Studs top and bottom. If compression is the least bit low, then I'll tear it down, measure, and rebuild. We'll see in a few days, then I'll report what I find.
Thanks
Do you know from the PO if it was using an abnormal amount of oil? I'd be very tempted to pull at least one piston (the one with the worst compression) while I had the heads off. Wouldn't take long and it could save you a lot of work later.
A cold compression check on an engine that hasn't run for several month isn't going to be definitive anyhow.
arveetek
03-08-2016, 06:50
I agree with the others. Tear it down now while it's apart. If everything looks good, then you haven't lost anything but a bit of time. It's really hard to test compression on a cold diesel engine anyway, as has been pointed out.
Casey
trbankii
03-08-2016, 07:12
Another vote for taking it apart now. I know the feeling all too well of totally reassembling something only to find out that I have to take it all back apart. As John says, at the very least, pull the worst piston to see what it tells you and go from there.
Save yourself the $$$$$$$ and leave the ARP STUDS OUT.
The TTY bolts work fine.
Just be sure the threads through the deck are clean and oil free.
The standard bolts come with a dry sealant, DONT ADD MORE OR MESS WITH IT.
Threads in the block need to be clean and DRY when installing the bolts.
Follow the torque sheet that comes with the bolts exactly
IIRC THE SPEC IS
First pass 20 lbs
Second pass 55lbs
Last pass 1/4 turn more
The sheet spells it out well.
YESSSSS, 1/4 TURN ON THE LAST PASS.
This puts the bolt into the "Stretch mode" and allows it to maintain proper clamping forces at all times from COLD TO HOT AND BACK AGAIN.
A proper metric tap run through all the head bolt holes is a real good idea.
To work good and last a long time, these engines don't need all manners of trick parts, just the proper factory stuff and good attention to detail and you're good for lotsa trouble free miles.
Same in the bottom end. Just use the factory bolts (These can be reused many times)
The TTY head bolts along with the Felpro head gaskets are engineered to do what needs to be done, and do it well.
The biggest reason for gasket failures in these engines are :
Improper installation procedure
Erosion of the deck surface at the front water passage
Over boosting.
Aftermath
03-08-2016, 15:07
So is it reasonable to pour diesel fuel in the cylinders to see if they leak down before I yank the pistons? Also, this engine already has ARP Studs, bolts etc. should I remove the studs from the block and reseal or not? Reportedly nothing was leaking.
Thanks
Chris
DmaxMaverick
03-08-2016, 15:27
No. They will pass fuel at an unmeasurable rate, especially 7 and 8. As said, a cold engine compression test is of little use, and (almost) none in your case. The rear cylinders are over-bored (normally 7 and 8, but occasionally include 5 and 6), and will usually show very low and/or inconsistent compression when cold, as does yours. I would not recommend any course that doesn't include, at least, ring end-gap and piston/cylinder diameter and taper measurements, as well as bearing tolerances. It's just too easy when it's already out and mostly apart.
What Maverick said :)
Also, don't trust anything.
If you are going to keep the ARP studs, then remove, clean the threads and reseal per ARPs recommendations
With a case like this you can't leave anything untouched, or assume anything.
The seller bailed on this engine, so you need to go through everything with a fine tooth comb.
One little item left to chance can wind up costing you time and $$$$$$$$$
Aftermath
03-08-2016, 21:16
Okay so check bearings as well for movement, no need for plastigage? I'll yank the pistons and measure.
You are likely going to hate me for mentioning this, butttttttttttttt
If this is indeed an AMG 506 block then it has oil squirters (should have) in the main webs.
If it were me, I would pull the crank and do a physical check of the ACTUAL PRESENCE of all 8 squirt nozzles as well as drop in a fresh rear main seal.
With the crank loose it's easy to slide a new seal into the bore and then square it up with the block using a straight edge, then button things up.
Ahhhh, just an FYI
Be sure you keep any and all bearings in the same spot they were run in previously.
Myself I use zip lock bags and a sharpie to sort and mark stuff when dissecting engines.
The last go round here saw the rig down for 4 years between tear down and the refit. (Health issues)
Everything was "tagged and bagged" and come time to reassemble it, things went smooth as silk.
GOOD RULE "TAGGEM AND BAGGEM"
As I said, DO NOT LEAVE ANYTHING TO CHANCE.
DO plastigage the bearings, as you have no clue where they are, and you are going to be right there.
The 506 squirt blocks, with the 8 big oil leaks in the bottom end (nozzles) need to have good close bearing clearance to keep anywhere near decent oil pressure at a hot idle.
On a non squirt block I like .0025" on the rods and about .003 on the mains, but the squirt blocks "bleed" so much out the squirters that the numbers need to be a bit tighter.
Taking any shortcuts with this engine MAY AND VERY WELL COULD turn up another FUBAR down the line after you have spent many hours wrenching on it.
Another tid bit.
While the heads are off, yank each lifter out and physically check each roller for any damage or strange wear.
Easy now, and really tough with the engine in the rig.
Check the timing gears (sprockets) and chain and if the chain is at all sloppy, toss in a fresh chain.
With these areas well looked over you should do fine.
Before you start the tear down, roll the engine to TDC and check the piston to deck measurement.
NORMALLY the pistons should be flush with the deck, but can be above by .005" with standard parts.
The one exception COULD be if this is an 18:1 engine using pistons that have an offset pin or a cut crown.
Get a piccy of the piston crowns and post it please.
Good luck
Keep the faith
trbankii
03-09-2016, 08:50
Lots of good advice here. While it’s apart - go over everything. Doing anything else is like building a house without making sure the foundation is structurally sound - no matter how glorious you build the house, if the foundation falls apart you’re screwed.
To justify what I said.
If the engine had been running great and there was little reason to do much other than maybe replace head gaskets while its out and easy to work would be fine.
But it seems that this engine has had a very dubious history with no real good explanations forthcoming, sooooooooooo, the only real safe course of action is simply to cover every and all bases.
If you leave no stones unturned and check it out completely, then when you are done you should have a good engine that will serve you well.
Cutting corners, no matter how small can end badly.
Taking anything for granted will end the same way.
Believing any second or third hand conjecture is even worse.
The 6.5 is not at all a hard engine to work on, but will bite you if you don't do it right.
Aftermath
03-12-2016, 13:32
Robyn; I'm told that these are .020 over and .010 under deck. TDC it looks correct. It's going to be a slow process so I can get it right. Thanks
Aftermath
03-12-2016, 13:36
Better pics of info on piston
I am concerned about that circular ring on the top of the piston.
That was made by a valve hitting the top.
These engine are real close inside, but not that close.
Are there any other pistons that show that same mark ???
This is not normal and could be part of what has happened.
I suspect that something is amiss inside the engine.
Timing chain or ????
I have never seen a 6.5 with valves hitting the piston crowns.
You had one broken valve spring, and this is not all that usual of a find.
Keep us in the loop
Good luck
:):)
Aftermath
03-12-2016, 16:45
Wow! Good eye with that. ...I'm overlooking the obvious, didn't even notice that....I'll clean and look at all of the pistons, chain, and report back. Thanks
Aftermath
03-12-2016, 17:31
It's the #7 cylinder with the broken valve spring. Its hard to see , but shows up well in the picture. No other pistons show markings on the top other than minimal carbon.
With the piston at TDC, what is the protrusion of the piston above the deck ??
if any ??
If the decks were cut, they can be cut .010" and the thicker head gasket used.
Now, this said, if the decks were cut and a thicker gasket not used the piston would be very close to the heads, but the valve should not hit the piston.
The valves should be well settled back into the seat long before the piston reaches TDC
That was an intake valve that hit.
Whats got me curious is if that engine has a broken crank shaft, or other serious internal injury.
You need to get that engine down to bare bones, I mean bare bones.
Check all push rods to see if any are bent (Roll on a flat steel table or glass pane)
If they wobble there are serious issues.
Yank every lifter and inspect them (Tag and bag to keep location noted)
Pull the cam and look for damage to the lobes.
Get the crank out and inspect.
Check the block over well.
My guess is that you will find the real reason the compression went away.
The valves hitting pistons can also explain the broken spring and if the valves were hitting the pistons there could be bent valves as well.
Snoop it out.
Possibly not as bad then.
The broken spring could easily allow the valve to "float" at higher engine speed and "kiss the piston"
Still
Look this thing over completely before you start putting anything back together
Aftermath
03-12-2016, 18:46
All of the pistons TDC is below deck, I did check that. The pistons are supposed to be .010 below
Stock is flush to .005 above.
Was this engine built to be an 18:1 compression
Aftermath
03-12-2016, 19:54
Again, I was told it was bored .020 over and the pistons were ordered. 010 under deck height. He said that he thought it was 20:1
Sounds good.
Once we get the issues sorted out the combination should be sweet.
A bit less Comp ratio will give you a bit more latitude on boost levels and will help with keeping EGT down out of the ozones.
18:1 has sort of become the "GO TO" spot for building a performance 6.5
Well now.
See whats in that beast and then it will likely become more clear as to why it has issues.
One thing ya need to do while it's down and all apart is to paint it "Cat Yellow"
Makes them "bullet proof" :D:rolleyes::D:D:D:D
Here is a piccy of the AMG 6.5 I built for my Dahooooley 4x4
Looks great and ya can see any oil leaks right quick.
phantom309
03-13-2016, 07:34
I want to know where the blog is with all the discussion on this engine,..
Does it have an aftermarket crank in it?
IF i were looking at this ,. i definitely would have stripped it to the bones as well,. i suspect there may be a crank issue,.
Did the motor come to an abrupt halt at sometime? i have pulled engines apart that have stopped violently,. (something in the drivetrain stopped, not the engine) and cams can get twisted and so can cranks,..
Just playing around checking for compressions won't help you, as robin has said,. motors aren't made of pfm,. things have to be "right' or it will cost you later,.
My opinion is stick with the studs,. they hold the lids on better under increased pressure,.:)
a5150nut
03-13-2016, 10:33
.
One thing ya need to do while it's down and all apart is to paint it "Cat Yellow"
Makes them "bullet proof" :D:rolleyes::D:D:D:D
Here is a piccy of the AMG 6.5 I built for my Dahooooley 4x4
Looks great and ya can see any oil leaks right quick.
Is that a crutch under the front of that motor to relieve the strain on the engine stand?
Close
It is a prop to take a bit of the strain off the stand.
That was a 3 legged stand that I added a full cross bar up front with wheels on both sides to beef it up, but a fully dressed 6.5 really makes me nervous sitting on there.
Good eye on that one.
Aftermath
06-03-2016, 21:03
Okay, so you guys suggested to tear this beast all the way down, so I pondered and ultimately did. Everything looks great and checks out. However, while it's apart, re-ring and bearing. I do want to run gapless rings. I just ordered rings and bearings. This engine is .010 below normal piston height, and .020 over sized. Didn't realize that the bearings are different sizes, and it seems that many rebuild their 6.5's without matching the block or crank codes to the bearing sizes.
So, discussion welcomed on this: I want to run the ATT turbo and stock IP, so Im thinking .010 over head gaskets to allow a bit more volume for the turbo. I'm also going to run a set of marine injectors that I've had for some time now. Hopefully the combination works and delivers power.
Thanks yall
Okay, so you guys suggested to tear this beast all the way down, so I pondered and ultimately did. Everything looks great and checks out. However, while it's apart, re-ring and bearing. I do want to run gapless rings. I just ordered rings and bearings. This engine is .010 below normal piston height, and .020 over sized. Didn't realize that the bearings are different sizes, and it seems that many rebuild their 6.5's without matching the block or crank codes to the bearing sizes.
So, discussion welcomed on this: I want to run the ATT turbo and stock IP, so Im thinking .010 over head gaskets to allow a bit more volume for the turbo. I'm also going to run a set of marine injectors that I've had for some time now. Hopefully the combination works and delivers power.
Thanks yall
If your slugs are already 010 below, then my money says you have a set of 18:1 pistons. They drop the compression ratio by moving the pin location up, which drops the crown. When inquiring about 18:1's, one of the mfg's did confirm that the pistons would drop below deck, but they would not tell me how far. Personally I would stick with a standard thickness gasket at this point.
Aftermath
06-08-2016, 20:13
If your slugs are already 010 below, then my money says you have a set of 18:1 pistons. They drop the compression ratio by moving the pin location up, which drops the crown. When inquiring about 18:1's, one of the mfg's did confirm that the pistons would drop below deck, but they would not tell me how far. Personally I would stick with a standard thickness gasket at this point.
I talked to peninsular where these pistons were originally ordered from (Mahle), and they told me that. 010 head gaskets would give me 18.1 cr. They're .020 oversized. and .010 under normal deck height so.........My next move is to de-glaze the cylinders with 600 grit ball hone? Any suggestions there? These cylinders really look good. 50k miles is right on. No top ring groove whatsoever.
I talked to peninsular where these pistons were originally ordered from (Mahle), and they told me that. 010 head gaskets would give me 18.1 cr. They're .020 oversized. and .010 under normal deck height so.........My next move is to de-glaze the cylinders with 600 grit ball hone? Any suggestions there? These cylinders really look good. 50k miles is right on. No top ring groove whatsoever.
Interesting as those pistons are supposed to give 18:1 with a standard gasket. Your engine to build as you please. Personally I would stick with a standard gasket if my slugs were 010 below deck (which is really more than 015 below standard installed height).
Aftermath
06-09-2016, 08:46
Interesting as those pistons are supposed to give 18:1 with a standard gasket. Your engine to build as you please. Personally I would stick with a standard gasket if my slugs were 010 below deck (which is really more than 015 below standard installed height).
But they are not standard bore size, they're. 020 over, which creates more volume
But they are not standard bore size, they're. 020 over, which creates more volume
Which is actually a piston that Peninsular does not sell - they only sell standard. There is another vendor that had Mahle make the 020 over, 18:1 piston. I have an email from May 5, 2016 (I'd be happy to forward the entire email thread to you), from Mitch at Peninsular confirming that they only sell standard bore and that the installed height is even with the deck.
Again, 020 over, 010 below deck, would be an 18:1 piston. If you don't want to take my word for it, use math to figure it out - compression ratio formulas and calculators are all over the internet.
Aftermath
06-09-2016, 19:38
Which is actually a piston that Peninsular does not sell - they only sell standard. There is another vendor that had Mahle make the 020 over, 18:1 piston. I have an email from May 5, 2016 (I'd be happy to forward the entire email thread to you), from Mitch at Peninsular confirming that they only sell standard bore and that the installed height is even with the deck.
Again, 020 over, 010 below deck, would be an 18:1 piston. If you don't want to take my word for it, use math to figure it out - compression ratio formulas and calculators are all over the internet.
JeepSJ,
Peninsular in fact DID sell these pistons to the last engine builder. I do have the receipts. I did discuss this with Mitch last week when I ordered the bearing set. However, Mitch did tell me several days ago that they no longer carry this particular piston and haven't for a few years now. It is my understanding, and according to Mitch, his understanding as well, that .020 oversized and .010 under standard deck is about 20.1 or a little less CR, and that .010 head gaskets get it to around the 18.1 CR mark.
I do appreciate the input as I don't want to make a mistake.
Thanks
JeepSJ,
Peninsular in fact DID sell these pistons to the last engine builder. I do have the receipts. I did discuss this with Mitch last week when I ordered the bearing set. However, Mitch did tell me several days ago that they no longer carry this particular piston and haven't for a few years now. It is my understanding, and according to Mitch, his understanding as well, that .020 oversized and .010 under standard deck is about 20.1 or a little less CR, and that .010 head gaskets get it to around the 18.1 CR mark.
I do appreciate the input as I don't want to make a mistake.
Thanks
Thanks for the clarification from Peninsular - Mitch made it sound like they never had them as an option.
As for the thicker gasket dropping your CR by 2 points...I seriously question that.
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