Search | Statistics | User Listing | Member Roster | Coach DB Forums | Albums
FMC Owner's Forum
Home -> FMC Owner's Forum ->  General Discussion -> Mechanic's Corner -> View Thread

You are logged in as a guest. ( logon | register )

ISO: Rockwell 4.33 differential gear set?
Jump to page : 1 2
Now viewing page 1 [25 messages per page]
View previous thread :: View next thread
   General Discussion -> Mechanic's CornerMessage format
 
andy1canada
Posted 2017-09-06 8:15 PM (#4957)
Subject: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Howdy all,

If you, or someone you know has an F-140 Rockwell differential with the rumored 4.33 gearing, I'd be interested in buying the guts or perhaps the entire unit?

Hell, shipping wouldn't be that bad; they can't weigh more than 500 lbs :-0

Trying to lay the ground work to do a 12-valve Cummins swap this winter.

If you can help, please let me know.

Thanks,

Terry
#846
Top of the page Bottom of the page
hemi354az
Posted 2017-09-06 11:06 PM (#4958 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Scottsdale, Aridzona
On 2017-09-05 7:37 AM, Florence Information Services wrote:

Terry,
4.63 was the fastest ratio for these. There was no 4.33 ratio released.
This has been out of production for decades. Parts that might still be available are found on the parts component list. If we don’t have them anymore, you might find them in the field somewhere.

Meritor Heavy Vehicle Systems LLC
Information Services
Florence, KY
Informationservices.florence@meritor.com
Phone Contact 1-888-725-9355 opt. 3
Grant Stidham

Damn Terry, the Meritor(Rockwell) guy told you YESTERDAY that there was NO 4.33 Ratio Gear Set EVERY MADE !
Why do you POST here a day later asking about one ?
You have been in the woods too long . . . drinking with Elves riding Unicorns.
Myth ON ! Lou #120

Top of the page Bottom of the page
andy1canada
Posted 2017-09-07 8:15 AM (#4959 - in reply to #4958)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Thanks Lou.

Yup, Elves & Unicorns and an occasional Green Flamingo, especially if they're buying!

Before I bought my FMC I'd read most every one of the nearly 10,000 posts on the Yahoo site. Then and since I've read reference to this 4.33:1 gearset; moreover, it's still referred to on the MCR website. Click the 'Parts' tab at the bottom, scroll down to 'Used Parts'.

I've left a message with Chris Hoagland (if the number on the OG Members database is still correct) and hope I can chat with him for clarification.

Just looking to put a potential 'ghost' to bed here, once and for all.

Thanks again,
Terry
Top of the page Bottom of the page
LCAC_Man
Posted 2017-09-08 9:00 PM (#4960 - in reply to #4959)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
Just put taller tires on it(22.5" wheels with a 255/70 tire puts you at 36.5" tall), you can accomplish the ratio change that way much easier than messing with that monster of a rear differential. If you don't want to do that then get a 6sp Allison and a stand alone controller which will give you the ratios you're wanting and give you tap shift, tow haul and a much better parking brake set up..
Top of the page Bottom of the page
hemi354az
Posted 2017-09-09 12:39 AM (#4961 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Scottsdale, Aridzona
PLEASE ! Tell us where you obtained your 22.5" dia wheels with 5 lug holes on a 8" bolt circle with a 6" hub center if steel or 6.050 hub hole if aluminum ? $$$ per wheel ?
What Ply Rating are your 255/70-22.5 tires ? What brand ?

The 7.50R17 Michelin XCA tire (still available), that fits STOCK FMC steel rims, is 31.2" dia.
But since I have Alcoas on my #120 and I am doing the arithmetic, I'll use the 19.5" dia Alcoa rim and tires that fit them for some comparison with Len's 36.5" dia tire suggestion.

Ignoring torque converter slip for a 15,000 lb vehicle at 65 MPH . . . a 19.5" 225/70 XZE tire (32.2"dia) will require 3140 RPM from the 440 gas engine. A 245/70 XZE (33.6"dia) requires 3009 RPM.
Using "some rim" that mounts a 22.5" 225/70 (36.7"dia) tire lowers the engine RPM to 2755 for 65 MPH . . . lowering engine RPM by 385 and 245 RPM respective to the 19.5" XZE tires above.
2755 RPM is still about 500-600 RPM too fast for a continuous operation "cruise" load of the engine.

What is YOUR engine RPM at 65 MPH in your 440 gas engined FMC 2900R ? Anyone ? What size tire ?

The Allison 1000 5 Speed has a 0.711 overdrive ratio, giving a 2232 RPM using the 225 XZE tire, and 2139 RPM using the 245 XZE tire, which is just about right for cruising with a 15,000 pound FMC.
The Allison 1000 6 Speed has the same 0.711 5th, and a 0.614 ration in 6th Gear, giving 1927 RPM or 1847 RPM for the two different XZE tires . . . which is too LOW a cruise RPM for a 440 gas engine'
The Allison 1000 5 Speed could be a better "matched" choice of the two.

While the Allison 1000 5 speed is about an inch or two longer (NOT INCLUDING some "adapter" to the 440 block) than the 727, so it could be made to fit, by moving the differential forward an inch or two forward (preferred), or the engine/transmission reward the require distance. The Allison 1000 (5 or 6 speed weigh essentially the same) weighs about 400 pounds dry, with converter. The 727 in the FMC is right at 168 pounds dry with converter, and a Chrysler 46RH 4 speed overdrive is 213 pounds dry with converter. So an Allison 1000 with 4 gears regular and one or two Overdrive gears weighs at least 243 pounds more than the 727 in a "stock" FMC 2900R . . . which violates MY PERSONAL FMC Rule No.1 - Do not add ANY weight behind the rear axle, which includes bumper stickers, no matter how small.

You may find out about a "stand alone" Controller for the Allison 1000 Transmission on the Nets, or "other" sources.
$2000, $3000, $XXXX?, and you could buy and INSTALL an Allison 1000 Transmission, and/or MAYBE some 22.5" rims and TALL tires that fit a FMC, and then you've got . . . what ? $400 Saddle on a $20 Mule ?
There might soon be another solution for the high RPM Cruise Speed of the "stock" FMC 2900R. Some of what I tell you is true.
Cruise ON ! Lou #120

Edited by hemi354az 2017-09-09 12:53 AM
Top of the page Bottom of the page
andy1canada
Posted 2017-09-09 7:29 AM (#4962 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Unfortunately its 'big-bucks' most any way you slice it. The more work you can do yourself the better.

A set of good 19.5" Alcoa's can run $3/k, more if there's a spare. The 22.5" wheels are more rare in this application - some had custom 6-lug hubs - so again more $$$.

The 'other' deal with 22.5" (according to Jimmy Black) was that they were prone to rubbing in the wheel wells. Would be good to hear from actual 22.5" wheel owners on this.

BTW: If like me there are other's out there who are not so great at math when comes to estimating end-game engine speeds with various gear ratios and wheel sizes, this might help:

http://www.crawlpedia.com/rpm_gear_calculator.htm

There's several different calculators out there but this should give you an idea.

Knowing the cruising 'sweet spot' of your particular engine helps.

Best,
Terry
#846
Top of the page Bottom of the page
LCAC_Man
Posted 2017-09-10 8:04 AM (#4964 - in reply to #4961)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
hemi354az - 2017-09-08 10:39 PM

PLEASE ! Tell us where you obtained your 22.5" dia wheels with 5 lug holes on a 8" bolt circle with a 6" hub center if steel or 6.050 hub hole if aluminum ? $$$ per wheel ?
What Ply Rating are your 255/70-22.5 tires ? What brand ?

Stockton Wheel can order steel 22.5"s, and there are a few others online that can as well, there a Turkish outfit that manufactures them, I think the cheapest I was quoted was $195 a wheel. Then you have the cost of tires. Not a cheap solution but if you have an aging set of 17's there is no cheap solution to that anyways, if your tires are in good shape this would be a foolish option.
I did also find a supplier that will sell aluminum blank wheels, again, not a cheap way to go, $200 per blank then another $200 per wheel in machining.

hemi354az - 2017-09-08 10:39 PM
The Allison 1000 5 Speed has a 0.711 overdrive ratio, giving a 2232 RPM using the 225 XZE tire, and 2139 RPM using the 245 XZE tire, which is just about right for cruising with a 15,000 pound FMC.
The Allison 1000 6 Speed has the same 0.711 5th, and a 0.614 ration in 6th Gear, giving 1927 RPM or 1847 RPM for the two different XZE tires . . . which is too LOW a cruise RPM for a 440 gas engine'
The Allison 1000 5 Speed could be a better "matched" choice of the two.

The 6 speed will always be the better choice, it doesn't just have a extra overdrive, the internals are improved, and the Tap Shift function is worth its weight in gold for the FMC application. The duramax makes plenty of torque at 1800rpm for flat terrain cruising and the mpgs jump up to over 20 (while towing) when you do. The key to the 6sp is to always drive in manual mode that way you're only a button push away from whatever gear you want.

hemi354az - 2017-09-08 10:39 PM
While the Allison 1000 5 speed is about an inch or two longer (NOT INCLUDING some "adapter" to the 440 block) than the 727, so it could be made to fit, by moving the differential forward an inch or two forward (preferred), or the engine/transmission reward the require distance. The Allison 1000 (5 or 6 speed weigh essentially the same) weighs about 400 pounds dry, with converter. The 727 in the FMC is right at 168 pounds dry with converter, and a Chrysler 46RH 4 speed overdrive is 213 pounds dry with converter. So an Allison 1000 with 4 gears regular and one or two Overdrive gears weighs at least 243 pounds more than the 727 in a "stock" FMC 2900R . . . which violates MY PERSONAL FMC Rule No.1 - Do not add ANY weight behind the rear axle, which includes bumper stickers, no matter how small.

An Allison sourced from a Kodiak/TopKick will have the commercial SAE bellhousing that will bolt to a Cummings.
He's talking about a Cummins swap...the weight discussion ended there. The most difficult part of that swap has nothing to do with getting the engine installed and running(12 valve cummins damn near run on prayers), it is all the structural/suspension work you need to do to support the saggy azz of the FMC. If you just swap a monster like that in there with the stock suspension you'll be all over the road, air bags (located behind the rear tires) to support the frame rails are an absolute must have. Substantial shear plating or tube structure improvements on the sides are also a must (if you care about things like being able to open you bedroom windows)..



Edited by LCAC_Man 2017-09-10 8:07 AM
Top of the page Bottom of the page
andy1canada
Posted 2017-09-10 9:51 AM (#4965 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Thanks Len; good stuff as always.

Clearly, logic and deep pockets are not major players in my proposed engine/trans swap. Simply put, I love this old engine and its going in my coach.

The weight thing will be addressed. The 6BT weighs in about 1000/lbs; 150 of that has already been mitigated by my Yammy genny swap. I expect the rad-swap will lose another 100 or so. Then there's other little things like moving the batteries forward etc.

The Cummins is still about 400/lbs lighter than the 8.2 Detroits that were all the rage a few years back.

Got the engine home yesterday. Guess I'm committed now... yeah I hear you Lou - "To the looney-bin Terry!" :-0

Terry
#846
Top of the page Bottom of the page
B. Sitton
Posted 2017-09-10 10:14 AM (#4966 - in reply to #4965)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Ignacio Colorado
Hope that lightweight genset runs on propane???
Top of the page Bottom of the page
andy1canada
Posted 2017-09-10 10:23 AM (#4967 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Me too, or it'll have to go!

Terry
Top of the page Bottom of the page
hemi354az
Posted 2017-09-10 12:11 PM (#4968 - in reply to #4967)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Scottsdale, Aridzona
My comments were based on "item" availability/source and resultant operation of suggested component changes as applied to 440 gas engined FMC 2900Rs.

Yea, yea, yea, I've heard all about what Stockton wheel can make cheap. There have been several FMCers that used them for 19.5" steel wheels and it was not without complications.
To date, no one has, or has had made, a 22.5" steel wheel that fits a 5 lug FMC.
The same can be said for "other" aluminum wheels for a FMC, in 19.5" or 22.5" . . . EXCEPT for the FMC unique ALCOAs ! There have been several other attempts to get aluminum wheels for a FMC made onshore, offshore, and on the Moon, that have not resulted in ANY wheels. I dulled my pick at that myself. If I remember right, FMC #1027 came from Sedona with 19.5 Alcoas already on it.

There are 1000 and 1 combinations to evaluate if you GUT a FMC of its engine, transmission, drive train and replace it with WHAT $?$?$?
Certainly there have been diesel conversions made on FMCs. How many? 12? 15? 25?
How many of them are the same ? What conclusions/lessons can be learned from they ones that are the same ? What conclusions/lesson can be learned from the "one of a kinds" ?

Given enough money, time, and talent . . . someone can take something that someone else made, modify it with and engine and transmission that someone else made, and call it "MY Pony Macaroni", and tell you a thousand ways it is better than what they started off with. That is called "HOT RODDING". Some Hot Rodders really believe that they can make a man hole cover FLY. But thousands of $$$s/Hrs later . . . it is still . . . a man hole cover.
Each to his own ! "I' like the Blue one better than the Red one, or the Green one, or the Yellow one, or the Puce one, or the Polished one, or the . . .
Satis verborum. Rod ON ! Lou #120


Edited by hemi354az 2017-09-10 12:19 PM
Top of the page Bottom of the page
LCAC_Man
Posted 2017-09-10 1:48 PM (#4969 - in reply to #4965)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
andy1canada - 2017-09-10 7:51 AM

Clearly, logic and deep pockets are not major players in my proposed engine/trans swap.


Yes, you just have to get good with that...if you're looking for a "payback" or an "is it worth it argument" (other than your own satisfaction)...you'll be disappointed. Hot rodding and fabrication are my hobbies...it keeps me in a productive endeavor which is better than the drinking hobby I had in my 20-30's.. I'm always happy to talk/give advice to folks who ask about the work I've done to my rig...but you'll never hear me say "you really should do it too".
Top of the page Bottom of the page
fcrives3
Posted 2017-10-10 10:47 AM (#5045 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Contributor

25
Location: Greensboro, NC
#934 runs 3000 rpm's @ 65 mph on 5 lug Alcoa's 245/70R/19.5's I too would love to do something to get rpm's down for economy LMFBO and try and save the engine also.
Top of the page Bottom of the page
LCAC_Man
Posted 2017-10-10 12:40 PM (#5048 - in reply to #5045)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
fcrives3 - 2017-10-10 8:47 AM

I too would love to do something to get rpm's down for economy

Drive 55...or spend a lot of money trying to save a little.
Top of the page Bottom of the page
fcrives3
Posted 2017-10-11 3:40 AM (#5049 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Contributor

25
Location: Greensboro, NC
Yeah I do that a lot anyway the older I get I get just a little wiser.
Top of the page Bottom of the page
andy1canada
Posted 2017-10-11 9:13 AM (#5050 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Morning,

After some deliberation I'm looking (again) at a wheel swap to get to the gear ratio I need. Several other owners have done this over the decades and Bill already suggested it a couple of months back. I poo-pooed the idea as I'm running a nice set of (Stockton) steel 19.5's with good rubber and stainless wheel covers that I'm happy with (thanks again, Dale).

So, stubborn as I can be, I started to focus on the diff and began to research and ask questions. Frank and others tried to get it through my thick-head that this would be a very (very) costly route to go but I figured there had to be a way to do it without selling my first grandchild. There isn't. So once I grasped the idea that it makes way more sense to slightly enlarge the diameter of the wheel rather than have a diff custom machined and installed in the coach, it became obvious. Surely, if a guy had to choose between a custom-built differential repair/replacement vs replacing a tire while broke down in the middle of Somewhere, South Dakota, the wheel-thing is the way to go. This resolution came as a great relief as now I'll run with the Rockwell - perhaps moved forward two or three inches - to help cram my SUPER-LONG-AND-HEAVY 12-valve in there somehow. (door's wide-open Len, fire when ready!)

I will sell my 19'5's as a set of 6 and use that towards either another set of 19'5' wheels that are wide enough (7.5 inch) to mount taller 285 series rubber, or, go with 22.5" wheels which are available in a 6" rim width with 38" tall rubber (8R/22.5) which likely wouldn't be too wide to fit the wheel well. I've found several 285 series 19.5's that are over 35" tall that would work but thus far they all seem to be drive-position tires. Also they all appear to be 10" wide or more which raises clearance questions.

For those of you (like me) not so great at math, I found some rpm gear-train calculators on-line that work like a hot-damn. I double checked a couple of different ones to confirm accuracy and settled with this one: http://www.crawlpedia.com/rpm_gear_calculator.htm

Useful tool I figure.

Regards,
Terry
#846





Edited by andy1canada 2017-10-11 9:16 AM
Top of the page Bottom of the page
fcrives3
Posted 2017-10-11 9:30 AM (#5051 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Contributor

25
Location: Greensboro, NC
So Terry where did you find 5 lug wheels that you can mount 22.5 tires on
Top of the page Bottom of the page
andy1canada
Posted 2017-10-11 9:54 AM (#5053 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
I haven't. Would have to have them built.

Terry
#846
Top of the page Bottom of the page
fcrives3
Posted 2017-10-11 10:07 AM (#5054 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Contributor

25
Location: Greensboro, NC
Yeah I figure there has to be a way to put a 4 spd auto in one of these things and still be able to keep the 440 intact
Top of the page Bottom of the page
B. Sitton
Posted 2017-10-11 11:39 AM (#5055 - in reply to #5054)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Ignacio Colorado
440 with overdrive.
http://www.fmcowners.com/mbbs22/photos/photo-thumbnails.asp?albumid...
A little over 100 miles on it. I live in the mountains and look forward to getting it out on a long haul.
I don’t think overdrive alone is the answer. The engine needs built for power in the low rpms. Smaller cam, and forget anything you think will help it breathe. Bigger manifold, lose bottom end torque, even dual exhaust loses low rpm torque. Rember with overdrive the engine now operates at much lower speed.
Bill
Top of the page Bottom of the page
hemi354az
Posted 2017-10-11 12:20 PM (#5059 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

1001002525
Location: Scottsdale, Aridzona
Each and every FMC Owner must prove to himself that pi are NOT square. Pi are round . . . cornbread are square. (https://www.mathgoodies.com/lessons/vol2/circumference)
This Gear/Tire Diam/Speed/RPM calculator is really easy for my limited math skills - http://www.advanced-ev.com/Calculators/TireSize/

So, what centering feature will you choose, Terry, for your your new and improved 22.5" x X width x Y offset for Z tire rim ? Lug or hub centered ? Pick ONE only.
There were some 19.5" rims made for a FMC Owner that Stockton Wheel (SW) made BOTH centers on. Owner had lots of trouble finding lug nuts for 3/4-16 studs that could be used with the rims SW made.
That FMC Owner finally figured out that he had to remove one of the two centering features. Which one ? Sorry, don't remember.
Maybe it would be better to actually HAVE in your hand the lug nuts you need BEFORE what ever rim centering feature you "order" from SW. SW can make anything right ?
Roll about the Center ON ! Lou #120

ps: drive position tire can be used in all positions. http://www.michelintruck.com/tires-and-retreads/tires/tires-101/tir...
pss: Good tinkin' to replace a over RPM speeding gas engine with a over RPM speeding diesel engine.
psss: even better tinkin' to replace a V8 length engine (4.32" bore X 4 = 17.28" ) with a longer I6 length engine (4.02" bore X 6 = 24.12" ) to add 7.84" length to the "swap" even before a transmission, with or without overdrive, is "figured in".
pssss: before you buy 22" rims (don't think you can "get there" with tire diameter and the 4.63 rear end) please see -http://ramchargercentral.com/diesel-talk/transmissions-for-the-cummins-pros-cons-and-what-fits-what/ - and
think about what transmission and output yoke and driveshaft you will need to fit between the engine and the differential . . . even if the differential is moved forward a couple inches . . . which Bill Sitton and I know works.

Edited by hemi354az 2017-10-11 12:39 PM
Top of the page Bottom of the page
LCAC_Man
Posted 2017-10-11 1:23 PM (#5060 - in reply to #5059)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
Terry,
What transmission do you plan to run with 12v? You can't be considering leaving the stock one in there... If you want to keep the budget in check you can run a 47RH or 4L80e, you'd get a more appropriately rated unit and OD... and all these problems go away..

Top of the page Bottom of the page
andy1canada
Posted 2017-10-11 9:16 PM (#5066 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Hey,

Thanks for posting all the great pics Billy. They really helped clarify what you tried to describe before.

What do you mean by 'Pi', Lou? Did you mean - pie? I knows what the pie is for sure.
The Cummins is also actually about 10" longer than the D Max, IIRC. Just means a little more finaggaling that's all :-)

Already have the 47RE Len. Turns out its mostly the trans of choice for the competition diesel crowd. They can be built very strong and controllers are somewhat more affordable, which is up my alley. The trans I have will need to be rebuilt and I plan to do it with my bro' inlaw as he's a pro mechanic and has done a few. So far I'm into the engine & trans for under $2/K. So far so good.

Terry
#846

Top of the page Bottom of the page
LCAC_Man
Posted 2017-10-12 7:02 AM (#5067 - in reply to #4957)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Extreme Veteran

1001001001002525
Location: Oceanside, CA
So all you need is a set of 8r19.5" tires (I run 12 ply Double Coin RT600s that are 34.1" tall) and that coupled with the 47re's .69 overdrive will have you at 2050rpms at 65mph...you've got no need to do anything else.
You will need to invest in that trans, stock it is only rated for a max of 19000lbs GCWR, you'll be at 15,700lbs or so with that cummins installed so your margin/safety factor is low and running a stock unit full time at that weight will reduce life.
Like you said there is plenty of aftermarket support for that trans, better valve body, torque converter and 6 pinion planetary gearset will provide a lot of extra strength.
Top of the page Bottom of the page
andy1canada
Posted 2017-10-12 8:06 AM (#5068 - in reply to #5067)
Subject: Re: ISO: Rockwell 4.33 differential gear set?


Veteran

10010025
Location: Victoria, BC. Canada
Yeah I hear you and would agree on your assessment of the trans. But I think the 2050 cruising rpm for the 12 valve is a little high; I've been told the sweet-spot is 1800 - 1900 for best economy. Over 2000 they start to drink. And we all know what 'drinkin' does.

Thing is, I usually run closer to 60 so I'll likely stay focused on the trans/engine install and see how I like it. If after licking my wounds from that, if I'm still suffering this lunatic-compulsion to carry on with this madness, I can always drop another $4 or $5/K for a wheel-swap to lower my rpm by a hundred or so :-o

I'm thinking a low stall triple disk TC should be on the trans-parts shopping list, too.

Have a great day!

Terry
#846
Top of the page Bottom of the page
Jump to page : 1 2
Now viewing page 1 [25 messages per page]
Jump to forum :
Search this forum
Printer friendly version
E-mail a link to this thread

Go to FMCowners.com HomeRunning MegaBBS ASP Forum Software
© 2002-2017 PD9 Software
(Delete all cookies set by this site)