|05-28-2011 02:37 PM|
I'll give you this: You've managed to keep a sense of humor throughout- something I doubt I'd have been as successful at!
But you can strive for perfection, or at least the semblance of perfection. Maybe after a few days of driving and some reflection, you'll have some ideas to run by the membership. I mean, we're in for a dime- might as well stay in for a dollar...
|05-28-2011 11:53 AM|
To keep this topic from a never ending story.
I'm happy for now! There is tons of info in these 18 pages which I ready every few days. With they way this thing runs now, it all makes sense now!
As a hotrodder, I'd like for it to be perfect but as a daily driver, I'm happy!
|05-28-2011 11:24 AM|
|05-28-2011 08:52 AM|
Looks like to me, they had to run less mechanical because the vacuum advance was too much (17 degrees).
they should had put in an adjustable vacuum advance canister and limit the vacuum advance to 12 degrees.
run 18 degrees initial (mechanical), then add another 12 degrees with the vacuum advance connected to a manifold source. (30 degrees at idle)
set total to 38 mechanical, then the total with the vacuum advance would be 50.
|05-28-2011 07:35 AM|
Its been just over a year and...well...yes...I am still alive!
Saved up some $$$ and took the Jeep to the shop. Auto Broker shop the specializes in high performance machines! I simply told them to drive it, smell it, dream about it, bond with it....inspect everything, test everything and call me with the results.
Compression test - good
New Distributor, Pertronix Flamethrower with the ignitor II.
Cut fireawall to fit
New Plugs and wires
11 deg initial
28 deg idle
53 deg cruise
36 deg WOT
idle 1,250 rpm, 15" of vaccum at idle
idle in drive 750rpm
This is the third "High Performance" shop that has worked on this thing in two years.
|04-08-2010 06:05 AM|
a part of the hot day coolant temp rise/fall,,,, is/was due to the wrong/lack of ign timing for the cam...
(a normal car with lack of timing will run hotter on the hwy)
now that the vac adv is working,,,(to help at cruise and a stop sign),,,you need to wait till hot weather to see if it does still bounce around....
the low cruise Hg readings says the motor is constantly lugging/working hard which generates alot more BTU's at cruise for the cooling system to remove...
(at cruise a motor should be "loafing",,,only takes around 60HP to maintain speed)
at a stop light at idle the pump doesn't move enough coolant thru the radiator to quickly cool a 500lb "heat sink" chunk of iron that sucked up to much heat while moving...
the block and rotating assembly LOVES heat,,,see attached wall wear test graph and do note that was only a 60 hour wear test!!!!
all of todays new cars are set to run at least 205 to 215* and motor warranties are out to 100K...
so 195-210 range isn't even a concern....
(the cooling system was designed for a 4L motor BTU output,,,,a 5.7L motor worth of BTU output makes it a out of balance system so some temp fluctuation based on ambient is likely,,,doesn't hurt anything)
as the chart shows,,,it's running too cold that is a problem!!!!
(till you reach such a high temp that the oil can break down)
|04-07-2010 02:01 PM|
|04-07-2010 09:43 AM|
be happy you only have to deal with one 500lb gorilla (the cam) and you already know how to beat it (re-work the centrifugal to 20 so the base can be 16 to make the cam happy)....
the obstacle is finding a time "window" that the Jeep can be down to get it done...
in the mean time,,,, don't use OD when you want better performance (to get the motor rpms and timing into the cam powerband)...
that IS the same results as having deeper rear gears and/or shorter tires....
1.0 ratio 3rd tranny gear x 3.54 rear gear "is" 3.54 final ratio
4th gear .70 ratio OD x 3.54 rear gears "is" 2.47 rear final ratio when in OD...
just food for thought:
you "could" put even taller tires on it and never use OD to get the cruise/mpg rpms where you do want them since you don't race once the timing is corrected....
(lot's of ways to skin a cat!!!!)
the yuch low 55mph Hg isn't really hurting anything except mpg when just cruising...
after another couple of weeks pull a couple of plugs to see if the jetting on the new carb is reasonably close to correct,,,some tan on the insulators....
otherwise,,,take a break,,, go do some other "fun" thing,,,"Rome wasn't built in a single day"
PS: 3.54 is a little better than the 3.31 you posted way back in this thread...
|04-06-2010 12:14 PM|
Decided not to dyno this time. The timing was way off. Was set to 53deg at 3,500rpm. Surprised I didn't break anything. The driver usually puts up with the vehicle, this time its the vehicle putting up with the driver...lol Funny, it started fine when hot too!
Mech reset the timing to 34deg at 3500 with a base at 10deg. Now that should be 10+27=37deg+14"= 51tt 37 is still higher than the set 34 but thats what he told me. He said the vacuum advance was set, working and pulling 6deg. Also said it looked like the mechanical was set to 27deg.
With all that reset and with the new Summit carb, I no longer have that hesitation as I did with the Eddi. Everything else is about the same.
So I guess its case closed till I get some gears and or an RV cam! It looks like I have 3.54 gears and not 3.73 gears. Should be able to get an extra 300rpm+ if I go with the 4.10 gears. This should push from 1,500 rpm at 55mph to 1,800rpm which is were I get some power. I may end up with an RV cam too. This Hot Rod stuff is getting on my nerves...lol
|04-03-2010 04:40 AM|
LOL but serious...
take the new Sears timing light with you so the mechanic can test/compare readings with the his light...
if possible,,,stay there and observe how and what he does....
(or atleast take a few minutes so he can demo what he does)
it's not starting over,,,he confirmed the motor behaves like it has a 220@ 50 duration cam,,,, so he will be setting the timing to be about 16b+20c+ about 10-15v = 46-51tt
DO mention to him when you get there,,,, the combo of 32" tires/gears and OD ratio is way low 55mph cruise rpms (for the cam power band) and the Hg is only showing 10-12 on a level road and drops with a minor head wind...
"that" makes a difference for how he may want to set up the dist...
|04-02-2010 01:33 PM|
Ok, back on topic!
Going to get the cent checked on the distrib Monday morning as well as the vacuum advance. Once that is confirmed, I'll start over...;-)
|04-01-2010 03:39 PM|
|Blue84JeepCJ7||Great info, thanks Red!|
|04-01-2010 06:56 AM|
thanks for the clarification,,,he set it to 33t "with the motor steady at 3500" is a big difference....
it for sure sounds like the fuel pump was crapping out (check valve leaking) but,,, a part of why it starts easy now is:
you are again back to approx the ign timing settings that the first mechanic set it to: 33t-26c= only 7*base approx
(more base is more counter resistance to rotation due to more Hg)
I can't recall the 55mph rpms in OD but it was way less than 2600 (cent all in) so there is not enough timing present at that speed with cent only added to get a decent Hg with your cam....
(there was a small chance the Edie was contributing to low Hg but that's now ruled out)
anywho,,,agree,,,drive it as is,,,, till the the hole in your wallet recovers some....
re: gears and tires and mph
32" tall tires means you are a special case for gears selection so be careful with interpeting what you read...
here's a whole set of calculators so you can plug in exact values to determine results (to determine what you do have and maybe do want):
I wouldn't spend time researching it now....
not until you do at least have the dist fixed (!!!!!) and then only after/if a cam swap and tune up results are known...
(you may hit a point of diminishing returns where the expense is not worth the gain,,,the vac gauge will tell you)
if/when gears is a needed consideration,,,,start a thread in the drive train forum...
|03-31-2010 03:18 PM|
|03-31-2010 07:12 AM|
your PM said the mechanic set the cent for 33*t all in at 3500,,,are you sure???
(it was all in/factory set at approx 2600? as I recall)
did they re-set/correct the cent adv to be 20*'s ???
(it was 26-28? according to your tests posts info)
timing would be 13b+20c=33t now with the cent corrected...
did they correct and hook up the new vac adv unit to add to the 55mph cruise cent timing???
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