3.4 truck build

[signalb]

Hello,
I'm looking to build up a rwd 3.4 out of a camaro into a serious truck engine for a 2.8 liter swap into my jeep comanche. Basically I want something that will be rock solid reliable for both street and offroad use and run naturally aspirated. I'd like to stay with a carb'd set up for the fact that it allows me to run on propane down the road but would be open to tbi as well. For horsepower I would like to make at least 190hp but preferably over 200 and of course the more torque the better. I'm hoping to make around 250 f/lb but not sure how hard this will be to achieve, at what cost and most importantly what will this do to reliability. I know there are people that can build these to over 300hp and higher but that's not what I'm looking for. Is 200hp and 250 pounds of torque an attainable goal and still be semi bullet proof?

[Superdave]

200HP/250TQ @ the wheels or at the crank?

The Camaro 3.4 is 160 HP/200 TQ, to pick up 40 HP and 50 TQ on that you are going to need some seriously ported heads and probably the Edelbrock carb manifold along with a good cam. You'll also need a good set of headers with at least a 2.5" exhaust.

You can pick up a bit more compression by using the 3.4 DOHC pistons, that might be something to look into.

[geoffinbc]

You not going to get that kind of power from the iron heads and natural aspiration. At least not a streetable engine suitable for off-road. The block, crank and rods will readily handle the power and for what your after you don't have to change or improve anything about them. A goal of 180 or so and about 220 torque is reasonable and will drive and run like a stock motor. I have a 3.2L build for my Trooper which I estimate to be putting out about that and it moves my 4000lb Trooper very well. Check my site and read up on the 3.4L swap guide and The 4.3L TBI swap. Then check my Trooper build and take a look as the gasket matching and some of the parts I selected.

If you go with the 260 cam you will get more power and torque will move up in the RPM range. Depending on where you prefer your torque to be you can make the cam choice. I like strong off idle torque and max torque in the 2000 to 3000 RPM range for highway cruising.

http://members.shaw.ca/betterthanyou

[signalb]

180 hp and 220 torque is pretty decent. This swap is for a 1986 Jeep Comanche so I'm a fair bit lighter than 4000 pounds. Basically I'm looking to be right around the range of a 4.0 in power and I think that sounds pretty close especially since the block weight on the 3.4 is about 200 pounds lighter than the weight of the 4.0. I'm also swapping the mechanical fan for electric so that should free up a few hp and except for the question of which power steering pump to use, it should allow me to keep the serpentine belt system from the donor instead of the V belts I currently have on my 2.8. If I go the carb'd route I was planning on using believe it or not an Autolite carb from ponycarburetors.com. My father in law has used them in the past for racing and they're pretty sweet. But, I'll admit your TBI setup has me thinking.

[geoffinbc]

Yea you will be in good shape. The 4.0L is a good engine and with the right mods can be made quite powerful. However it is very heavy and not as efficient as the 60 Degree V6.

Having EFI is very nice especially if you ever go off road. There is simply no comparison between a carb and EFI. Once you switch you will never go back. I drove my father in laws 66 Chevelle last summer with a 396, Edelbrock heads, intake and carb which are all brand new. While it did drive ok the throttle response and the odd flat spot as you ease into the throttle get annoying. And Edelbrock carbs are supposed to be the best driving carb out of the box. And just recently I drove a Samurai with a Weber carb conversion and the same drawbacks were very apparent. When you hit about 80% throttle is acted weird for a few seconds and then cleaned up and away she went but if you mashed the throttle it was OK. None of these quirks are for me.

If your after an easy way to convert to TBI the check out an Isuzu rodeo 3.1L, Isuzu Trooper 2.8L or an S-10. I think the Isuzu's will be a better harness for a donor since they received the GM engine as kind of a transplant themselves so the harness looks like it would be a good candidate and remember to grab the ECM which is under the console of a Trooper or behind the drivers kick panel in a Rodeo. I haven't tried myself but I think the Rodeo 3.1L 'MIGHT" run the 3.4L with stock 2.8L injectors. But I have not verified it but may try it in my S-10 in the future.