Help needed for a 258 distributor on tester. - Page 2 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Help needed for a 258 distributor on tester.

FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectJKS Now Available at www.baseline4x4.com, Trackbars, SkidsFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye Kit

Reply
Unread 07-13-2013, 05:30 AM   #16
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,644
Taking .025 off the block or head of my Saturn would have netted me 10:1 CR.

86cj74.2L is offline   Reply With Quote
Unread 07-13-2013, 07:35 AM   #17
swatson454
Mall-crawlin' Hot Rodder
 
swatson454's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Dripping Springs, TX (soon)
Posts: 4,858
Got it. PM sent


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote
Unread 07-13-2013, 09:05 AM   #18
ninjakid
Senior Member
 
ninjakid's Avatar
1987 YJ Wrangler 
 
Join Date: Mar 2011
Location: Chalfont, Pennsylvania
Posts: 989
Quote:
Originally Posted by 86cj74.2L View Post
Taking .025 off the block or head of my Saturn would have netted me 10:1 CR.
Felpro head gaskets and just about every other head gasket out there is in the .045 range when installed.
Used original is 0.25 thick.
My new pistons and just about every other 258 piston in the sub 300 category is .010-20 shorter.
Mine seem to be .015.
I have to redo everything and make sure all my calcuations are correct once more but if I slapped the engine together as is my quench would be somewhere in the .070-80 range and dcr somewhere in the high 6 to low 7's range.
Doesn't seem ideal to me.

Quote:
Originally Posted by swatson454 View Post
Got it. PM sent

Shawn
Thanks for the help.
__________________
96 XJ 4dr, 4.0, AW4, NP231,
87 Wrangler, 4.2, TF999, NP231
ninjakid is offline   Reply With Quote
Unread 07-13-2013, 09:43 AM   #19
swatson454
Mall-crawlin' Hot Rodder
 
swatson454's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Dripping Springs, TX (soon)
Posts: 4,858
I just got this response.

Quote:
Originally Posted by bill jones
-I have seen that story---but that machine is alien to anything I have seen.

-all that electronic stuff I know nothing about at all---never seen a machine like that.

-about the only answer I could have supplied was the one about the looseness of the chuck--and someone else answered that nearly word for word what I would have said.

-I have three of the older machines mechanical driven machines---I have removed ALL of the old wiring---and changed the motor drive pulley ratios to speed up the rpm to where I can test to something over 9000 engine rpm.

-then I installed fairly simple all new 12vdc wiring and put the plug wires off to the side on a 5" diameter round cap style receiver that I can adjust the spark gap from 1/8' out to about .900" or so.
---------------------------------------
-they are totally different concepts of machines.

-the only thing about your friends machine that might be neat is the variable speed motor---if it is capable of spinning the distributor shaft 4500 or so.

-I wouldn't worry much about the first 200 rpm problem.

bill

Shoot

Question: do your new pistons have a quench pad?
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote
Unread 07-13-2013, 09:56 AM   #20
ninjakid
Senior Member
 
ninjakid's Avatar
1987 YJ Wrangler 
 
Join Date: Mar 2011
Location: Chalfont, Pennsylvania
Posts: 989
Tbh I'm not surprised at this point.
This machine is so very different than all the others out there.
I'm lucky to actually find someone else with one even if he insists I gut it and install this expensive log box.
Pistons are identical in shape to the oem pistons minus some slight changes to the rings and being shorter.
__________________
96 XJ 4dr, 4.0, AW4, NP231,
87 Wrangler, 4.2, TF999, NP231
ninjakid is offline   Reply With Quote
Unread 07-13-2013, 12:29 PM   #21
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,644
I think the thicker gaskets are to keep the CR from increasing with a overbore.

If its anything like the saturn's there should be a few different brands of gaskets of varying thickness. If you shop around.

I do wish I would have gone up to 10:1 on the Satty.
86cj74.2L is offline   Reply With Quote
Unread 07-13-2013, 02:10 PM   #22
ninjakid
Senior Member
 
ninjakid's Avatar
1987 YJ Wrangler 
 
Join Date: Mar 2011
Location: Chalfont, Pennsylvania
Posts: 989
Quote:
Originally Posted by 86cj74.2L View Post
I think the thicker gaskets are to keep the CR from increasing with a overbore.

If its anything like the saturn's there should be a few different brands of gaskets of varying thickness. If you shop around.

I do wish I would have gone up to 10:1 on the Satty.
Felt relatively good enough at first to do some simple calculations.
Difference in both scr and dcr in a calculator between 3.75 and 3.78 in a stock with no other differences 258 is 258.11/4.23/9.17:scr/7.38dcr and .0398 quench stock, 262.26/4.3/9.3:1scf/7.48:1dcr and same quench.
Stock with a .045 head gasket is 8.8:1scr, 7.09:1dcr and 0.598 quench.
30 over is 8.92scr and 7.19dcr and same quench.
I don't think the little increase in cr is gonna make it ping but I can't see the lower cr and bigger quench as anything but detrimental to performance.
OEM .025 compressed metal gasket and .047 felpro mls. 1373744796783.jpg

At one point mopar performance made a somewhat thin head gasket but they discontinued them a long time ago and I'd rather not rely on a head gasket that would be hard to find a replacement for.

Even the people that stroke 4.0's complain about the head gaskets and how the thinnest made is .041 or so even with a bigger market for 4.0's.

Either the enginetech specs are wrong or my manuals are.
1373745126665.jpg
.022-23 difference in height verified between multiple new and old pistons, not .015 which is the difference is when you use info from the manufacture website and oem specs in a couple different calculators.
Which is why I have to double check everything myself which is such a pain with these stupid headaches.

1373745293680.jpg

Not sure if I need this oil hole or not.
1373745318677.jpg
__________________
96 XJ 4dr, 4.0, AW4, NP231,
87 Wrangler, 4.2, TF999, NP231
ninjakid is offline   Reply With Quote
Unread 07-13-2013, 03:20 PM   #23
swatson454
Mall-crawlin' Hot Rodder
 
swatson454's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Dripping Springs, TX (soon)
Posts: 4,858
Ninja,

There is such a little quench pad, I don't know how much it's going to matter. Odds are good it's going to ping at anything much over 9:1 no matter what. I don't know, I certainly could be wrong.

We get the same thing with SBC heads from the late 70s and 80s smog heads. They just rattle. Whatever you do, though, never use a thicker gasket to drop the compression ratio. That'll make it ping for sure.

It looks like the guys may have some direction on your tester.


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote
Unread 07-13-2013, 04:24 PM   #24
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,644
Put the Singh's grove in the head and that will direct the flame towards the outside edge of the cylinder where the flame jet will burn all the unburned hydrocarbons caught between the top ring and the top of the piston.

Those unburned hydrocarbons stuck between the top ring and piston crown is why newer engines have a much less distance between the top ring and piston crown. And is also a major source of detonation. The Singh's groove eliminates that.
86cj74.2L is offline   Reply With Quote
Unread 07-13-2013, 08:54 PM   #25
ninjakid
Senior Member
 
ninjakid's Avatar
1987 YJ Wrangler 
 
Join Date: Mar 2011
Location: Chalfont, Pennsylvania
Posts: 989
Quote:
Originally Posted by swatson454 View Post
Ninja,

There is such a little quench pad, I don't know how much it's going to matter. Odds are good it's going to ping at anything much over 9:1 no matter what. I don't know, I certainly could be wrong.

We get the same thing with SBC heads from the late 70s and 80s smog heads. They just rattle. Whatever you do, though, never use a thicker gasket to drop the compression ratio. That'll make it ping for sure.

It looks like the guys may have some direction on your tester.

Shawn
Was wondering about that.
Some quench is better than no quench though right?
9:1 dynamic or static?
.045 quench is what I was aiming for by zero decking the block and using the felpro head gasket to achieve that, I think dcr would be in the 8.8:1 range supposedly.
I can't remember for sure though and seeing how many holes I have in my memory I'm probably mixing it up with something else.

Intersting semi-random fact, my mopar performance handbook (which more focuses on the 4.0, amc v8's and the v8's found in the grand cherokee than the 258) says that 4.0 wrist pins are slightly offset to reduce piston slap when cold and in exchange for more slap when warming up you can flip the pistons for slightly more power and torque.
No mention of quench in that little article in the book.
Understood on the thicker head gasket and I was not planning on doing something like that.




Quote:
Originally Posted by 86cj74.2L View Post
Put the Singh's grove in the head and that will direct the flame towards the outside edge of the cylinder where the flame jet will burn all the unburned hydrocarbons caught between the top ring and the top of the piston.

Those unburned hydrocarbons stuck between the top ring and piston crown is why newer engines have a much less distance between the top ring and piston crown. And is also a major source of detonation. The Singh's groove eliminates that.
It is something I have been looking into along with some side research on dimpling the ports like a golf ball surface in the rare moments I am headache free.
There are quite a few interesting (and spirited) discussions on speedtalk I'm going through about it.
You've got the people that swear by it and others who say its nothing but a gimmick.
Supposedly it is more suited for low rpms which if true would be great for the 258 assuming I don't do one of my not so rare nowadays moments of stupidity and cut too deep if I decided to do it.
__________________
96 XJ 4dr, 4.0, AW4, NP231,
87 Wrangler, 4.2, TF999, NP231
ninjakid is offline   Reply With Quote
Unread 07-13-2013, 09:25 PM   #26
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,644
Most people talk themselves out if going it.

I did everything to the satty head but the surface tension porting of the intake.

The combination of the valve mod and the Singh's grooving increased torque enough that the second time I started the engine after the head install the PCM went into adaptive mode to relearn all the shift pressures. Within 5 miles all shifts firmed up drastically.

Grooving the intake ports and bumping the CR to 10:1 is my next step. But that head will most likely go on a fresh bottom end not one with 201,000 miles.
86cj74.2L is offline   Reply With Quote
Unread 07-14-2013, 06:17 AM   #27
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,644
Oh yea, forgot my claims.


I regularly average 38 to 40mpg for the tank. That's a combined city and rural driving. 31 miles each way to work. This last tank specifically was 38.5mpg and two days I took 422 to work which is all city driving and 36 red lights in 25 miles. Plus each day a 1.2 mile trip to Grammys to run the dogs.
86cj74.2L is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.