3.4L Improving on Low End Torque

[emptypockets86]

Hey guys. I have a '86 Cherokee with a 2.8L. I picked up a 3.4L out of a Camaro a few months ago to swap in. I'd like to improve on the low end torque for crawling purposes. I was hoping someone could point me in the right direction to some things I can do to achieve this. Thanks!


Sent from my iPhone using Tapatalk

[Blacktree]

You want to improve the engine's pumping efficiency at low RPM. Some things that should help with that:

-- Look for a camshaft with increased lift and maybe a little more duration, but not a lot more overlap. Something like the Edelbrock 3790 or Crane H260 should do fine. Or put 1.6:1 rockers on your stock cam.
-- You can increase compression by shaving the heads and/or block deck, or by installing 3.4 TDC pistons. I wouldn't suggest doing both, because you may run into clearance issues.
-- Find or build a set of long-tube headers.

That said, I think the Caddy 4.9 V8 would be perfect for what you want to do. Thanks to its aluminum block, it weighs about the same as a 2.8 / 3.4 V6. And it produces plenty of low-end torque (rated at 200HP / 275TQ). It also has the same bellhousing bolt pattern as the 60-degree V6. Just a thought.

[Kaos]

So that's why people put them in fieros and stuff so often


Sent from my iPhone using Tapatalk

[Blacktree]

So that's why people put them in fieros and stuff so often

Yeah, there's no need for an adapter plate, which reduces the cost of a swap considerably.

[Kaos]

Which means...... My malibu may just need a 4.9 lmao. Maybe some day. Is there much aftermarket support for the northstar?


Sent from my iPhone using Tapatalk

[Blacktree]

The 4.9 V8 is a different engine from the NorthStar. Actually, it's the predecessor to the NorthStar. But the NorthStar uses the same bellhousing bolt pattern. Neither engine has much aftermarket support.

Anyway, I think we're getting off topic.

[caffeine]

From what I've read the 4.9 doesn't typically do very well when pushed beyond stock.

The northstar is a bit better but typically will have a head gasket problem at some time in its life. There is a fix that involves heli-cooling the head bolt threads or something like that.

[SappySE107]

LS1. Cummins. I mean seriously, what are we talking about any more? When we recommend aluminum block V8s with wet sleeves and iron heads, something is wrong. Top end swap to 3500, custom cam for torque, and keep the stock pistons for 11.5:1 compression. Thats what I would do with a 3.4 iron head that I wanted to rock crawl.

[geoffinbc]

Best bank for the buck for what you are doing is a COMP cams K Kit. Get the 252 cam not the 260. I have it in my Trooper motor and it kicks ass. The Magnum 1.6:1 rockers are a nice addition and they are under $150 for the set. These parts will wake your motor up big time and everything is less than $500 including all the little stuff like gaskets and fluids. You can stuff them in before the swap.

[emptypockets86]

Thanks for the input guys!


Sent from my iPhone using Tapatalk