Swapping L35 Vortec V-6 into 1968 Jeepster Commando

[Scott9]

I stumbled onto this forum while researching my 68 Jeepster Commando rebuild.  What a great bunch of folks, thanks!   I currently have a 225 v6, running good, but stock.  I've built and added bumpers, winch, rock sliders etc.  so with all that and tools its gained a bit.  Also running 33" tires, 4:56 gears with a SM 465 and Dana 20.  My dilemma is should I rebuild the 225 (which is my first inclination) or try to find an EF 231?  So far my plans for either one would be a stock rebuild but with Comp 252H cam, Offy dual plane intake with EFI and  dual exhaust.

I want to stick with either the 225 or 231 because I want to just drop one in, and I've been working on this for long enough.

I would like more low and mid range power.

Any thoughts would be appreciated.

Scott 

[Moses Ludel]

Hi, Scott9!  Glad you're with us, and very pleased that you have a classic Kaiser Era Jeepster...Nicely equipped, too!

I do prefer the second generation 231 with even-fire, which provides an independent crankshaft journal for each connecting rod.  You would immediately know the difference.  If you're looking for a bolt-in replacement and no major modifications to the chassis or other key features, the 231 is a good choice.  What are your thoughts around EFI?  Aftermarket?  Let's kick that around.

If your Jeepster's weight is not too bulky, and if you're not trailer pulling, the 231 is sufficient.  The 252H camshaft choice, as you know, is my favorite for bottom end to mid-range, where you will run this engine.  When demand calls for it, the 252H will produce good power to 4,500/5,000 rpm.

When you source an engine, you will need a late '77-up RWD application engine plus a 231 even-fire flywheel.  The odd-fire 225 and early 231 (1975-early '77) use a different flywheel.  Both types are 160 tooth and externally balanced, so if you need flywheel numbers, please ask.

In my Jeep® CJ Rebuilder's Manual: 1946-71, I discuss the even fire 231 V-6 that I built for my '55 CJ-5.  Balancing and match weighting are important on any V-6, so if you are rebuilding the engine, take that into account.  You'll like the performance of a fresh 231, a reasonable improvement over a stock 225.  Do no mix long block parts between the two engines.

If you have any intentions to trailer with the vehicle, I would consider an LS GM V-8, either the 5.3L or 5.7L.  There are wiring harnesses available, and the bolt-up to an SM465 could be relatively easy.  You would need a cooling system upgrade for the added horsepower.  There is also the earlier Vortec 4.3L V-6 truck engine with TBI or the smoother L35 with a counter-balance shaft and port injection, each needs a wiring harness splice-in:  A 4.3L TBI harness might be available from Howell Engineering if you pursue this path.  There is also the traditional "small-block Chevy" 350 V-8 iron block/head engine for utility and cost savings.

Your highway use should be the determinant, you can easily "get by" with the Buick 231 V-6 off-pavement with a Dana 20 and compound low like the SM465, one of my all-time favorite transmissions!  Also, if you're running the original front axle, the engine weight, especially with the winch and bumper is a consideration.  So is the axle stamina when considering more horsepower/torque and 4.56 gears (a 9-tooth pinion).  What type of front axle are you running?

Looking forward to discussing your project...Feel free to post photos!

Moses

[Scott9]

Thanks Moses:

As far as EFI goes, from what research I've done, and talking with people that know a lot more than I do, I think that is the route I want to go with anything.  Not stalling on inclines,  ease of cold weather starts, use of the evil ethanol gas, and mileage (the big one), are all factors.

I'm guessing I've added about 700-800 lbs. with the full to-the frame rollcage and what I listed above.  As far as a trailer, the most would be a small ATV trailer with ATV.  And that would be just to a camp site or jump off point.  I pulled one to Yellow Rock in High Rock Canyon (I'm guessing you're familiar with the area).  Anyway, it took a beating!!  Good conformation on the cam, thanks.

Any suggestions for sourcing an engine?  Since you're in the Reno area,  I'm about 4hrs. north.  Whenever we fly it's out of Reno,  and we seem to make it down there few times a year.  The air races and Street Vibrations etc. Really not far for  us.  I'll start scrounging around here.

I ordered your Jeep Owners Bible and 46-71 manual.  I'm sure they will be a great resource.  I'm a fair mechanic/ fabricator, but I need lots of input.  Thanks to some good friends, and now you, I believe it's all doable!!  

I've considered all the replacement engines you mentioned.  Of all of them I'm more inclined toward the 4.3 Vortec.  Lots of them around for a reasonable price, and cheaper to rebuild than the 225.  And here I thought I had my mind made up!!  But, I want to do it right for my application, the first time!

My axles are the weak point, I believe.  I have a fresh rebuilt Dana 30, 4:56 with a True Track in front and an AMC 20 with Chromalloy one piece axles, 4:56 and Detroit Locker in the rear.

Thanks for sharing your knowledge.  I'll work on posting some photos.  I'll be 70 in a few weeks and this computer stuff is not my strong point!! 

 

Thanks Again

Scott

[Moses Ludel]

Scott9...High Rock Canyon is a favorite local run, a long day-trip or a refreshing overnight camp out.  Glad you have access!

The early CJ book will help if you do the 231 V-6.  The Dana 20 and AMC 20 will need a factory workshop manual, your Dana 30 front is similar to the 25 and 27, I also cover the Dana 30 at the magazine.  I do cover these pieces (AMC 20 axle, Dana 30 front axle and the Spicer/Dana 20 transfer case) in the later 1972-86 edition of the Jeep CJ book series.  Thanks for the interest in the earlier book, buying two books could get spendy and is not being suggested here.

A 4.3L Vortec V-6 with TBI would be very reliable and an easy mate to the SM465 transmission.  The trick with EFI conversions is wiring.  Contact Howell Engineering and ask if its wiring harness for the Jeep 4.2L inline six TBI conversion is available separately.  Howell uses a GM TBI unit similar to the Vortec 4.3L V-6.  Ask if that wiring harness will work for a stock 4.3L TBI V-6 and as an interface with the stock Vortec V-6 ECM.  Howell sells an ECM but the one that comes with a 4.3L V-6 donor engine might work if the wiring harness will interface.

Interested in your project.  Pleased, too, that we share the High Rock Canyon venue, perhaps we can cross paths there at some point!

Moses

[Scott9]

Moses

Yes, High Rock is great!!  We enjoy the entire 3 corners area.  Cal, Nev. and Or.

I have an original shop manual.  And I bought one of your books used from ebay, so it didn't hurt much!

I'll get in touch with Howell and see what will work.  I have a chance to pick up a 99 Blazer  for next to nothing.

Thanks again for the info.  And I to hope we cross paths.  When I get this thing back together we'll be hitting the trails!

Scott 

 

 

 

[Moses Ludel]

Scott...A '99 Blazer would be an excellent donor for the engine.  If a manual transmission S/T truck, that would be helpful, too. 

I meant to ask which steering gear you have in the Jeepster.  A Saginaw power gear would be optimal for the 4.3L GM V-6. 

Moses

[Moses Ludel]

When we plan to visit High Rock Canyon, I'll let you know...Here is a link to a freelance magazine story with my photos from a decade ago:

http://www.fourwheeler.com/events/1006-4wd-high-rock-canyon/

[Scott9]

Thanks Moses.  The Blazer is an auto, but I have a flywheel and bellhousing. 

I have a Saginaw power steering conversion.

Absolutely!!  Let me when you plan on going to High Rock, or anywhere in the area.  We go to The Alvord/ Fields Denio area quit a bit also.  I'll check out your link.  Thanks.

[Moses Ludel]

Scott...Perfect candidate for the 4.3L Vortec V-6, of course you'll need motor mounts, exhaust and such, the cooling/radiator may need upgrading for the added BTUs of the higher horsepower engine.  Once done, the engine will fit nicely and make a sensible alternative to the vintage 225 Buick.  No substitute for cubic inches!  Install the right crankshaft pilot bearing, and you're good to go.

You'll really value TBI for the reasons you cite.  Saginaw power steering is great...Please take photos of the conversion and post them here!  Others will appreciate your work and the achievement.

Have only been through Denio and across the Sheldon Antelope Range to the Black Rock.  Great petroglyphs at the area, would very much enjoy visiting there!  We'll keep that one in mind, we can access from I-80/Winnemucca and up 95?

Moses

[Scott9]

Moses

Picked up the Blazer today,  will start on it tomorrow.  The Jeepster is empty now. 

I will have to get help from the kids I work with on how to post photos, but will get it figured out.

Yes, you can take I-80 to 95, then to 140.  Hope to see you out there sometime.

Scott

[Moses Ludel]

Scott...This should be a straightforward swap, a 4.3L Vortec V-6 with TBI, much easier to address than the later L35 with CPI.  I'm excited and trust you will be happy with this effort in the long run.  Not overkill, the V-6 should fit well, you have the P.S. already and could even run A/C with this engine...I like it!  Photos will be great...

We enjoy the Winnemucca area, Santa Rosa Range and Denio country.  In-laws have done the petroglyphs and camped in the area you describe.  We really enjoy Great Basin archaeology and evidence of the First People.  Let's keep this in mind.  We have the Ram and travel trailer, the XJ Cherokee and a wood-deck car hauling trailer.  We can even drive the XJ to Denio for that matter...The XJ works well for trails like High Rock (milder for a 4x4 route), we drive the XJ from home to HRC.

Moses

[Scott9]

Sounds great Moses!  Just the inspiration I need to get this done.

And I just finished getting the Jeepster where I THOUGHT I wanted it....ha...ha!  The 225 just wasn't going to get it.

I'll do photos and keep you updated.  This working kind of gets in the way!

Scott

[Moses Ludel]

Yup, it's that "work thing" again...!  The Vortec V-6 should reap noticeable results without taxing the geartrain or raising the fuel bill, Scott...

There is no substitute for cubic inches.  The 4.3L Vortec TBI engine was a substantial "base engine option" in GM full-size pickup trucks and SUVs.  262 cubic inches for great bottom end torque!  You have the donor vehicle for wiring and the ECM, too.  That will save cost.

Thanks for the pending photos...You'll enjoy documenting this swap.  Starting that topic thread will be valuable to others!

Moses

[Scott9]

Hi Moses

I've been working a lot, and getting things together for the swap.  I decided to go with a GM reconditioned long block after some calculating.  $1200- 1500 for machine work and $500 for a rebuild kit, plus making 2 200 mile round trips to drop off and pick up.  It was $1998.00 from Jegs, 3yr. 100k warrantee ( that only applies to selected vehicles which I'm sure isn't mine), but if they have that much faith in them, then that's an escapable risk, for me.  And delivered to me with no core charge. Made sense to me.

I send the computer and harness to Jims Performance, that will be $450.  And I ordered a 56-410-8 Comp Cam, Scoggin Dickey.  $271.00.  Things are starting to come in, so I can get started in earnest soon, and get some pictures coming.

Also, I'm considering incorporating a cross brace with the motor mounts, just a thought for now.

That's the update for now.

Scott

  

[Moses Ludel]

Hi, Scott...This camshaft is for the 1992-2014 4.3L V-6 with a balance shaft (originally designated as the L35 engine).  Is that the long block you're getting, with a roller hydraulic type camshaft?  

You'll need to confirm that this is also the replacement long block for a TBI engine if your donor engine from the S-Blazer has TBI and not the L35 engine's CPI (central point injection).   Does GM show your reman long block as a direct replacement for the engine in the S-Blazer?  That engine has TBI not CPI, right?  No balance shaft?  Or is it CPI with a balance shaft (L35)?

The CompCams 260 hydraulic camshaft should not be too radical with the roller hydraulic lifters.  I normally run the milder High Energy Series 252H grind, which apparently is only available for the earliest 4.3L V-6s without the balance shaft; the early engines use flat tappet hydraulic lifters.  Your Jegs/GM long block has roller hydraulic lifters?  A balance shaft?

If the reman engine is an L35 or balance shaft type with roller hydraulic lifters, the 260 grind you ordered should fit and work well...The reman long engine should come with new or reconditioned roller lifters.  Your 56-410-8 order is the camshaft only?

Moses  

[Scott9]

Hi Moses....The long block is a direct replacement, with hydraulic roller cam, and CPI with a balance shaft.  It is an L35.  Yes I got cam only, no need for new roller lifters as far as I know.

I'm still doing some mock up with the original Blazer motor.  Once I get past that, progress should move right along......I hope.  As my Dad would used to say "every job is a custom job"....aint it the truth?

Thanks for all the input.

Scott

[Moses Ludel]

You're Dad was right, Scott!  I like to use the term "Project" with a capital "P"!...In my earlier career, I was consistently optimistic about the work involved in makeovers and upgrades, building 4x4s for magazines and even the SEMA Show...I eventually learned that the work starts then develops a life of its own.  We go along with the end result in mind.

The OE-type hydraulic roller lifters should work with the camshaft.  Confirm with CompCams...The CPI/L35 is a smoother package, you'll like the end product...You should have a very reliable package with off-the-shelf service replacement parts that are readily available.  Good idea for a backcountry traveler!

You'll need to upgrade the cooling system if you haven't already.  Approximately 45 BTUs per horsepower, the radiator must handle the GPH/GPM flow rate plus the added horsepower/BTUs.

Would like to know more about Jim's Performance and what they do with swap engine EFI computer harnesses...The info could be valuable to others, Scott...

Moses

[Scott9]

Hi Moses

We've had some business and family issues.  I should be able to get back at it within the next week or so.

I did get the harness back from Jims.  He eliminated all unnecessary wiring to give me a stand alone engine control only.  All connections are labeled, computer is flashed,  I'll let you know how it works when I get there.  He also installed a code reader port.

I've got the cooling covered.

I'll be back ASAP.

Scott

 

 

[Moses Ludel]

FAMILY FIRST, Scott...Sounds like Jims did a thorough job on the harness.  Are the terminal ends molded?  How do they handle the connections?  Plug types?  The OBD-II port is very useful if the OEM G.M. ECM is still storing codes.  Nice!

Electronic connections must be free of ohms resistance.  I use rosin core solder and multi-layers of heat shrink tubing on interlaced wire splices.  In it for the long haul!  I like this approach...

I took a peek at Jims Performance website (http://www.jimsperformance.com/).  So, your harness for a L35 CPI system is custom and one-off for Jims?  Does the shop also do TBI harnesses?

Moses

[Scott9]

Hi Moses

Sorry for the extended absence.  We've had quite the roller coaster this summer.

Jims uses all original connectors, so it's all plug and play to original plugs, sensors etc.  He had done harnesses like mine before, sounds pretty routine for him.  Yes, he does TIB stuff too.

I've made some pretty good progress, not as much as I'd like, but it's getting there.  Everything is in.  Just lots of little things now.  Lots of "every job is a custom job."

Something that seems so simple as an sm 465 top cover proved to be a major thing.  Never have been into one before,  but with the small parts kit and a lot of try and retry, it's all good.

I hope to be up and running soon.

Thanks

Scott

 

 

[Moses Ludel]

Exciting, Scott!  How did the motor/front mounts turn out?  Did you use a weld-in kit? Any photos to share? 

Engine position is governed by driveshaft, transfer case and crossmember location.  This should be a nice fit with the 4.3L V-6, both of the engines are 90-degree design.  How are you handling the exhaust? Using the L-35 exhaust manifold?

You're running a Saginaw P.S. gear.  Are you using the L-35 pump?  Adapters for metric-to-inch are available, compare/confirm pressure requirements and output for your streering gear and the later pump.

Engine cooling? Are you upgrading the radiator to match the higher BTU demands of the L-35?

You'll really like the punch of this engine.  So much smoother with the balance shaft when compared to the odd--fire Dauntless 225 V-6!  Enough torque to qualify for full-size 1500 pickup base engine status.  Should provide equal or better fuel efficiency and unaffected by altitude with the EFI/CPI!

Moses