trenace
Needs a job
Posts: 3056
|
posted August 29, 2005 07:13 AM
Max spacer plate with stock cam chain? And how thick is stock base gasket?
What is the maximum thickness spacer plate that can be used while still using stock cam chain?
Mr Hill helped me with this but I wound up confusing myself in not being sure if the 0.100" figure referred to maximum thickness of the plate before being compressed, or 0.100" after being compressed.
I haven't opened the motor yet, as I'm waiting on my parts to do so. Am I correct in thinking that wihout the stock base gasket, this gives zero deck height or only just a trace "in the hole"?
And what's the compressed thickness of the stock base gasket?
What I want to know is how much longer rods I can run while using the thickest spacer plate I can. That should be, the compressed thickness of the thickest spacer plate that can be run, minus the compressed thickness of the stock base gasket, if I have things right.
Thanks!
  
|
VincentHill
Needs a life
Posts: 6520
|
posted August 29, 2005 11:03 AM
When I asked this question, about the compressed thickness I was told that the reason the .060 plate was .063 was because it compressed .003. After seeing your question, my question is is the .100 spacer .103 or .100. If the compression is only .003, then that does not make a lot of difference. Remember this is an Aluminum plate and is made out of fairly stout (read Hard) aluminum. I will call Falicon and see if I can get a definite answer on this. I think the non Metal Gaskets were the real problem where they are .020 and squeezed down about .007 to .010 after torqueing.
Last, I will try to remember who told me that the Max thickness was 0.100 before you ran out of Cam chain. I actually think it might have been someone at MRE or the other (Turbo) Piston Maker in Florida
____________
Made History @ Daytona and still one fast old man!!
|
trenace
Needs a job
Posts: 3056
|
posted August 29, 2005 11:16 AM
Thank you Mr Hill!
|
VincentHill
Needs a life
Posts: 6520
|
posted August 29, 2005 12:11 PM
Call the person at MTC because I know that time is of the essence for what you are doing also the answer man at Schnitz may know
____________
Made History @ Daytona and still one fast old man!!
|
trenace
Needs a job
Posts: 3056
|
posted August 29, 2005 02:41 PM
I really avoid asking questions of companies I'm not buying something from, so I can't ask MTC... I could ask Schnitz as I've purchased from them but this item isn't directly related... Falicon ought to know though and I am doing at the very least crank work from them and possibly the rods also if they will ever give me the weight of their rods!
So I'll ask Falicon, that seems the best approach. As double insurance though it would be great if anyone has run an 0.100 Falicon spacer and knows it worked, and if someone knows the compressed thickness of the stock base gasket? Wouldn't have to be the same person on both questions!
|
oldkawboy
Needs a job
Posts: 2125
|
posted August 30, 2005 07:28 AM
Tre....
I was told the stock base gasket was 0.010", when I removed mine it measured 0.008".
Dan
|
trenace
Needs a job
Posts: 3056
|
posted August 30, 2005 12:07 PM
 Edited By: trenace on 30 Aug 2005 13:19
Thank you!!
That would tend to support -- let's see if Falicon says the same -- that if a nominally 0.100" spacer plate can be run, and that is the actual thickness when compressed, the rods would need to be 0.092" longer (2.337 mm) to get zero deck height.
Which would improve the rod ratio from 1.575 to 1.617. Not a big improvement (comparable to, for example, increasing a hypothetical 350 Chevy's rod from an unusually-short 5.48" to a still-short-but-now-nearly-stock 5.63" just to help visualize it) but might as well get it while there anyway.
|
entropy
Moderator
Posts: 8671
|
posted August 31, 2005 03:40 AM
trenace, I am currently set up with .080" spacer + 2 x .010" ss gaskets + .005" copper gasket, and have no problem with the timing chain (manual tensioner).
BUT, I have taken .0015" off the block and .003" off the head. I don't know how much compression of the gaskets there is. I measure my quench directly, so I just add/subtract gaskets to get my target.
____________
This moderator uses moderation in moderation
|
Ra12r
Zone Head
Posts: 919
|
posted August 31, 2005 04:21 AM
A 5mm stroke is a 2.5mm spacer + base gaskets with no cam chain issues.
____________
All must bow to the "Ra Supremecy"...
|
trenace
Needs a job
Posts: 3056
|
posted August 31, 2005 06:41 AM
And 2.5 mm is 0.098".
Actually Ra (this is something I realized before but then FORGOT) that is the simplest approach. It's already known that given configurations work for +5 mm stroke, which is an extra 2.5 mm each way.
So in other words, stock stroke with +2.5 mm rods should work EXACTLY like stock rods with +5 mm stroke, in terms of where the piston sits in the hole.
So unless the typical +5 mm configuration actually is not at zero deck height and it would be preferable for the piston to be a little higher, sounds like +2.5 mm rods would be the way to go.
I'll be talking with Falicon about it also, soon as I get it confirmed that the piston pin bore is in fact going to be in the same relationship to piston crown as stock (as I believe it will and I have wanted it to be.)
|
entropy
Moderator
Posts: 8671
|
posted August 31, 2005 08:58 AM
Edited By: entropy on 31 Aug 2005 10:02
trenance,
Prolly I don't understand something, but "zero deck height" = .027" quench w/Cometic 3 pc head gasket... I hope you aren't going in that direction.
____________
This moderator uses moderation in moderation
|
trenace
Needs a job
Posts: 3056
|
posted August 31, 2005 09:35 AM
If that gasket gives only .027" then zero deck height would be too high... I am going to get a figure from both CP Pistons and Falicon (since Falicon should have an idea how much their rod stretches) on the minimal squish I can run but I would think that would be at least 0.030" or 0.035."
So that really should have read "deck height giving mimimum safe squish."
|
entropy
Moderator
Posts: 8671
|
posted September 01, 2005 12:41 AM
Edited By: entropy on 1 Sep 2005 01:42
trenace,
The advice I have gotten (from the experts) on quench hight is:
.038-.040" for drag racing where you will certainly go into the limiter now n' again
as low as .030" for top end racing where the limiter can be avoided.
I have un-intentionally "experimented" with too tight quench in the past, and have a couple sets of junk pistons to prove it  . GREAT dyno numbers, real bad ju-ju for 1/4mi longevity.
Now I use a junked head where I have cut out most of the material above 1 combustion chamber, so i can torque it down and actually measure quench; my new set up will have .040-.041", 15.2:1 CR.
____________
This moderator uses moderation in moderation
|
trenace
Needs a job
Posts: 3056
|
posted September 01, 2005 10:46 AM
Thanks, Entropy!
In normal riding I avoid the limited but I'd like the engine to be able to spin to 12,250 (or wherever the extended rpm limiter puts it.)
OTOH, if I can run a tighter squish at 11,650 (or whatever the exact figure is) as a rarely-used redline, that would be probably be more productive than having to run a looser squish so as to be able to get an extra 600 rpm on rare occasions.
Falicon hopfully will have some knowledge on their rod stretch...however what I've found thus far is that they can be slow and not always so communicative by e-mail, but very good on the phone. I may have to call to get what they have to say on it.
|
trenace
Needs a job
Posts: 3056
|
posted September 01, 2005 11:25 AM
Edited By: trenace on 1 Sep 2005 12:31
Just as a thought -- I wonder if it's possible with a borescope to see that a piston has "kissed" the head?
If so, then one could have a squish that is fairly tight but, on the basis of experience others have had, sure to be good for say stock redline; then verify that there is no touching at stock redline; and then ease up the limiter 100 rpm at a time with very short runs and inspect to see if any such kissing occurs. If so, then back down 100 rpm or whatever amount from that point.
It certainly can be visible when the head is off the motor, so perhaps it's visible with borescope? Or is that a totally whacked idea? I only had it 30 seconds ago so it's not thought out.
Entropy, did you run into your problems of pistons touching the head at stock limiter in the ZX-12R with stock conrods at a given clearance, or with Carillos? I would have hoped the Carillos would stretch less?
|
entropy
Moderator
Posts: 8671
|
posted September 02, 2005 12:35 AM
i had OEM rods. Now I have Carillos, but I am NOT going tighter than .040".
I could have set quench at .035 by taking out the .005" copper, but .040" is just about where I wanna be (.038-.040")
I dont think that the issue is an increase in rod stretch from 11.6 to 12.2.
For me, the problem is when the motor bumps the limiter and flaky stuff happens. I have no proof, but my guts tell me that hitting the limiter is not good for my motor.
It is not that easy to see when the piston has kissed the head. Carbon doesn't really build up in the quench area.
BUT, kiss the head and say good night to rod bearings pretty quickly.
____________
This moderator uses moderation in moderation
|
trenace
Needs a job
Posts: 3056
|
posted September 02, 2005 03:05 AM
OK, that makes sense. Thanks!
I will see what Falicon says -- if they're confident their rods stretch some amount less than stock, then I'd feel that would entitle me to go that much tighter than say your 0.038" figure, but not tighter than 0.030." If they're not sure on that point then I probably should go for the 0.038."
About how much "in the hole" does a piston wind up with for example the 0.080" spacer plate and the gaskets you'd recommend (and which are those, if you would?)
Secondly, well I know this is another go-around on this same question, but the Cylinder Head Shop in the the UK, that I just asked about porting, gave me an initial recommendation or at least quotation of going to larger valve size. Now to me, with bore being increased a significant percentage, unless the original manufacturer just made the valves too big in the first place, it makes sense to increase valve size proportionally. But quite a few here recommended against increasing valve size. I pointed this out to them in my follow-up reply just now but only in the sense of, several who are experienced with it have recommended against it.
What do you think?
It is not too late, I suppose, for me to ask CP to make the valve cutouts a little bigger, maybe.
|
entropy
Moderator
Posts: 8671
|
posted September 02, 2005 03:34 AM
I have about .013" in the hole (.013 + .027 = .040). BUT, you need to compress the block/spacer/gaskets to get a good reading, and even then gotta be careful about the piston rocking in the cyl.
My base gasket set up is "special" because my block has been milled.
If you wanna be anal about quench height, and don't mind paying postage, I could send you my modded head so you could measure the quench directly.
I get my .010 ss gaskets from Kwak, my .005 copper comes from Cometic. Contrary to VH's experience, I have had 110% good product and service from Cometic.
Valve size: The experts I trust all lined up on NOT putting oversized valves in so I didn't give it a second thought.
____________
This moderator uses moderation in moderation
|
gunner
Needs a life
Posts: 5778
|
posted September 02, 2005 07:09 AM
Damn Trenace that offer of a cut away head sounds too good to pass up.
____________
There's no such thing as a motor with no more power to give only people with no more intelligence to get it
|
trenace
Needs a job
Posts: 3056
|
posted September 02, 2005 11:29 AM
Edited By: trenace on 2 Sep 2005 12:29
Actually I'm not sure how having the modified head would help, as my head won't be milled, and what advantage it would have vs using my own head and the stock gaskets and seeing what the squish presently has, I'm not sure.
However I'd actually like to get Falicon rolling on making those connecting rods now rather than messing with that first, but perhaps I need to. The info still doesn't wind up being directly applicable since I am not using the 0.100 spacer presently nor necessarily the same gaskets in the new build with the 0.100 spacer. (Entropy, do you have specific recommendations?)
Well, it's somewhat flexible anyway, as I could plan on using 0.005 and 0.005 and if that winds up short, use 0.010 and 0.005 or at worst double up with 0.010's.
Does anyone have a figure on what the squish tends to be stock?
|
entropy
Moderator
Posts: 8671
|
posted September 03, 2005 03:14 AM
my "modded head" has all the material over one combustion chamber removed so I can torque it down then see/reach directly the quench area and measure the gap. I put feeler gauge blades on the piston, then rotate past TDC, adding thickness till it begins to bind. That thickness = actual quench height.
much more direct than trying to compute the gap. I was .010" too tight by doing the "in the hole + headgasket thickness = quench height" method.
I thought stock was .055+/- but I am not sure.
BTW: gunner, I am not thinking of donating my modded head , lending it, maybe. it was a PITA to hog that baby out, and that "tool" will be used every time I put my 12 motor together.
____________
This moderator uses moderation in moderation
|
ninja12
Needs a job
Posts: 3310
|
posted September 03, 2005 09:44 AM
Karl,
Why do you alway make me do this?
You know the rules.
Post the picture like a good little board member. 
Thanks in advance.
|
trenace
Needs a job
Posts: 3056
|
posted September 03, 2005 06:28 PM
Edited By: trenace on 3 Sep 2005 23:20
Entropy, thanks! That head sounds pretty cool. I would think though that I can measure the squish with solder, particularly if the valves aren't installed yet.
I think I may just say the hell with it and have Crower make titanium rods. If I have them built to the same weight as Carillo steel rods, that should be a rod with really minimal stretch, letting me run a tight squish with better confidence. Besides that, built that beefy, the fatigue issues of titanium at high load might be bypassed. If they are not too expensive and not too slow to deliver, I may go this route.
So let's see... let's suppose stock is .055 squish and say I am aiming for .032," trusting the Ti rods to stretch less. So this is shortening by .023". However I also want to use the 0.100" spacer plate. Combining this with the lesser squish, this is taller by 0.123".
Let's say that the plan is to use two .005" coppers. Compared to the stock stainless steel base, that should be no change, or perhaps shortening by .001" accounting for that possible extra compression. So that makes taller by .122".
If the head gasket used is the same thickness as stock (is it??) that is no change, so that leaves .122" (3.1mm) extra rod length as what's needed to compensate for the 0.100" spacer plate and the tighter squish. Now this raises the question, why the extra 0.5 mm when the 0.100" spacer plate is correct for 5 mm stroked motors which take up an extra 2.5 mm of height?
Well, figuring in the 0.023" (0.584 mm) reduction in squish, that comes out to +3.084 mm which agrees very very closely.
Triple-checking, you are running the stroker and so that accounts for 2.5 mm right there. You have milled a total of .0045" (0.114 mm) and so since I am doing no milling, to get the same squish as you I would need 2.614 mm extra rod length.
But if (trusting in the Ti rods to stretch less than stock) I aim for 0.032" squish, that is 0.008" (.203 mm) less than yours so that gives a total requirement of 2.817 mm extra rod length.
Shit that do not match up at all, do it. About +2.8 mm trying to make a direct comparison with your motor, vs. about +3.1 mm from the other two methods.
Well, if I specify +3.00 mm and the "right value" is 3.1 mm, that increases my squish by 0.004" which is not so bad, still gives me 0.036" which is still pretty aggressive though likely more conservative than needed with such strong rods.
Whereas if the "right" value is +2.8 mm, I need 0.2 mm of extra base gasket to account for it, which is .008", so increasing to the 0.010" steels (provided the cam chain will still take it) would be correct.
I guess then, barring useful further info, that specifying +3.00 mm is about correct...
Karl, actually if you could doublecheck my reasoning in comparison to your motor that would be much appreciated. Except for that reasoning, I'd specify +3.1 mm instead of +3.0 mm. And, is the Cometic head gasket the same thickness as stock. Thanks!
|
entropy
Moderator
Posts: 8671
|
posted September 04, 2005 09:48 PM
ninja12,
I have Matt's (wideout) dig camera but am busy wrenching; getting close to be back to the track
trenace,
too many assumptions for my liking; why not just mock the motor up and start adding spacer + gaskets until the cam chain says no mo? Ti rods are like $4000/set, so i wouldn't take any chances.
i haven't seen a stock headgasket in 4 years, no idea how it relates to the 3 pc cometic.
very interesting project you have going!
____________
This moderator uses moderation in moderation
|
trenace
Needs a job
Posts: 3056
|
posted September 04, 2005 09:55 PM
Edited By: trenace on 4 Sep 2005 22:57
Absolutely I am going to measure it rather than bolt it up and hope it is right. Thing is, I want to order a correct rod length in the first place to go along with the 0.100" spacer and the reduction in squish.
Of course it would be simpler if I did some mocking up before ordering the rods but thing is, I'm trying to ride for as long as possible before opening the motor and then trying to keep the downtime fairly short.
It seems to me on further though that 3.1 mm is correct... if that is the spacer plate is indeed 0.100" compressed and the head gasket is the same as stock. Those are the two facts I need to verify. If those are true, then 3.1 mm equals 0.122"... and 0.100" of that will be the spacer plate and 0.22" will be the reduction in squish. Adjusted as needs be if I learn different on the gasket thickenesses. But I gotta get these rods ordered pronto. Fortunately, just finding out about those gaskets shouldn't be hard.
Or, if the Ti rods are indeed $4K, then I would want to open up the squish a little from that, so call it +3.0 mm. Hard to figure why it should be so much extra for Ti but till I ask I certainly don't know; it's discouraging to learn that it could be that high That would not be worth it just for the sake of a little tighter squish, that's for sure.
Thanks for your help and the kind words!
|
|
|
HOME
NEW TOPIC