Dauntless V6 Questions

Hi I am new to the forum, so for forgive me if this is an overpost. My wife and I just purchased a 67 Cj5 project and it came original with the 225 V6 but is currently a rolling chassis. We both want a 225 back in the old girl but I have a lot of people trying to talk us into a 231 swap or a 4.3 SM420. I see no reason for this. As far as I'm concerned unless you find a Grand National with a turbo there are not any 231 motors that put out the numbers of the 225. To get to my point are there any companys out there with goodies for the 225. I know I can get a 4bbl intake for them but it is pointless in my opinion if you can only run a 390 CFM carb. I have no interest in fuel injection, so I'm wondering what is the best 2bbl set up for these motors, and maybe some companys that produce some go fast goodies for these motors. I also have the factory T86-AA trans and want to upgrade. How hard is it to adapt a T-18 to the Buick 225 dana 18 combo. Any and all input and recommendations are greatly appreciated. Thanks for your time and thanks for reading.

 

You can find a T-18 that was an option for these, but they are getting scarce. As far as "upgrades" do a search here for odd fire upgrades or 225 upgrades. Others will chime in, but I would start with headers, cam, HEI, etc... of course if you want to spend the coin start searching kenne bell and the sky is the limit. I am sure Nickmil will chime in but he has a ton of info on getting these to blow SBC's out of the water when it comes to mud drags and such. Oh and by the way Welcome from CT fill out your profile, you never know when someone is in your backyard so to speak

 

rather than hunt down a t18, I would use a SM420, NP435, Muncie 4spd or whichever 3spd the v8's used.

 

Just to comment;

Are you comparing the pre-1970 225 numbers to the 231 numbers? Before 1970, HP and torque were measured in gross numbers (no accessories) and after in net numbers. Apples to oranges. I expect that an odd-fire 231 and a 225 will be essentially identical in performance and potential. The 231 is a 225 with a 0.050" larger bore and some production changes that prevent exchange of some of the components. Practically speaking, they are the same engine. The bore change unified the bore diameter with the Buick 350, making production line logistics easier.

The even-fire 231 is a different engine, but again I expect the performance potential is the same as the odd-fire 231 or the 225.

I believe the main reason you would go with the 231 instead of the 225 is availability. The even-fire 231 is arguably a better design, though I'm sure you'll find ardent fans in both the even-fire and odd-fire camps.

The 4.3L is another viable option, mostly because of price, availability and support. The rear-mounted distributor of the 4.3L makes mounting the engine a little more complicated (firewall interference in the 225 location), and the engine mounts would have to change. However, there are lots of cheap go-fast parts for Chevys, many more than for Buicks. The factory TBI for the 4.3L is also very appealing - a vast improvement over any carburetor, and especially suitable to a Jeep.

 

I'm still searching for a 225 Dynamometer chart but; yeah Tim's spot on..
There is a notable difference between Gross and Net torque readings.
And you can nearly forget about the HP rating.
There is no real way to measure HP it is merely a calculation based on the actual torque readings.
The earliest Dauntless engines including those of the early 1960's Buicks were rated at 225 ft lbs of torque @ 2400 RPM.
Later Jeep 225's were rated at 235 ft lbs of torque @ 2400 RPM.
The only difference being a change from 1 barrel to the 2 barrel carburetor.

 

I thought one of the things that puts the 225 over the 231 is that is has a heavier flywheel. For a Jeep application I thought the heavier flywheel is more beneficial.


TD

 

Is it a straight bolt on to the 231 ?

If that is the case then the 231 wins hands down.

TD

 

We are still up in the air as far as upgrades. The Jeep will mainly be used for trail riding, getting back to some fishing holes, but I also want enough pep to be able to climb hills at the dunes or on the trail. As far as the trans goes I really don't want a creeper, I was considering also a T15, or t150. I dont know exactly what that would take to do though. I am dead set on a odd-fire motor though. Guess I just love the rumble from the old motors. As far as the specs I did get them from a Chilton motor manual. I have a odd fire 231 75-76 year of build. But according to the manual it was only rated a 110 hp. I was told when i bought it that it was a 225. I should have taken my motor manual with me. $50 Later I now have a boat anchor with a busted trans mount ear thanks to my neighbor. I already have a line on a 225 in good running condition from someone doing a V8 swap for $150. As far as the add ons I have a set of headers in good shape that came with the Jeep. and I have the HEI, from the 231 OF. Can I use the intake with the Rochester 2 jet on a 225, or should I opt for the 4bbl with a 390 if I am using headers.

 

I'm going to stay out of this conversation as I am still learning myself. I just wanted to say "Welcome from Central Arkansas"

 

Welcome from MI...I also have a 67 CJ5 with a 225!

 

If you plan on keeping your Dana 18 and offset rear axle, the T-150 can only be used with the Dana 20. It uses a special bull gear with a seal shoulder that was only made for the Dana 20, and won't mesh with the Dana 18.

The T-15 is an excellent transmission, and very sturdy. Plus the ratios work well - I like the T-15. The easiest route for you would be to buy Novak's adapter http://www.novak-adapt.com/catalog/kit_1415.htm to bolt up a AMC-era T-15 to your V6 bell.

 

Thanks for all the Welcomes! If I use a T-15 what all will I have to change. I checked out the adapt kit from Novak. Can I still use the main shaft, or will that have to be changed out too? Also what are the weak links in a T86-AA. I was told they are worse than a T14, but I ran a T14 in my 75 CJ5 hard for 3 years with a healthy 360 and never had an issue. But I also ran synthetic lube in the trans. Not sure how it would but I was told it would help. I've heard from several people that the T86-AA was to weak for the Jeeps in stock form, let alone a modified engine. However I was told the same thing with my T14. My wife and I are on a tight budget with this build so dependability is a must. Are there any era specific trannys I can run that would be a sturdier choice without the use of adapters, T98 maybe???

 

If you get a T-15 from a '72-75 304 CJ or from '71-79 258 Wagon or J-truck, you should be able to bolt it in. You'll likely have to move the crossmember back a little and change the lengths of the drive shafts, but the OAL will be close to the original setup. You will need a 6-spline output gear that matches the Dana 18 - Novak has a chart of the gears and what they fit http://www.novak-adapt.com/knowledge/transfer_case_gears_grid.htm If it were mine, I'd go through the transmission before installation.

Everything depends on the habits of the driver. However, if you had a 360 connected to a T-14, and it held up fine, I'd say you'd be happy with the T-86 (or T-90) and V6 setup. The T-86 is very similar to the T-90 in function and strength. Both are synchronized on only the 2-3 and 3-2 shift. The guts of a T-90 will go in a T-86 case, but you cannot mix T-90 and T-86 gears. impact load is what causes catastrophic failure most often. Realize that you won't have a lot of capacity for abuse - no burnouts, speed-shifting, etc. and if you get in a bind among big rocks, you will have to be careful how much throttle you use.

The T-98 is a granny-gear transmission, and only offered in Jeeps with the F134. The T-18 with a V6would be easier, and be functionally the same as the T-98.

 

I swapped in a t-18 out of a ford truck, and run a 225. I love the combo. I've also done the sm465 harder conversion and a huge tranny but a good swap. The t-86 is a crappy tranny but for mild wheeling probably will hold up. You can also upgrade to a t-14 (from a 68-71 cj5) you'll gain a little strength and sincro first gear. about 1" longer but an easy swap. I think the granny 4 speed was one of the best upgrades I've done to my Jeep. Good luck.

 

Ya, the T-15 gear reduction ratios look very good.
But the wide range T-18 gear reduction ratios look even better if you accept its rather large weight/dimensions.

 

Thanks for all the input guys. Sounds like i've got alot of decision making to do. I've owned radical, now i just want practical and fun. The wife and I have even thought about just dropping a 134 in the Jeep, but I would prefer the V6. With the price of the adapters to upgrade to a different trans it looks like I might just tempt fate and run the t86 until we can afford better. Most of the trails we run are mild 2 tracks and old fire trails so the Jeep wont be seeing much hard core action, other than dune cruising, if i can ever make it to Silver lake again. Anyway thanks again for the input. I really like this forum and all the knowledge you guys are willing to share with dummies like me. Have a great Thanksgiving everyone!!