Tired 3.5

[astateofmike]

Okay, Newbie question:

3.5, 180k....still runs, but lacks in power uphills and stuff. I may just not be familiar with the power/torque she had new...

This may be me just used to a 200hp engine in my stock s10 blazer which has 120k and stillpulls like a horse, but I know the time will come to do some work.

Question: Why does the engine get "tired"? If the fluids are all changed and all maintenance was done (as I know the PO took care of her and told me how to continue to....) then why tired? And is is better to rebuild with the same block or just go looking for a bigger / better motor?

May seem obvious to some, and I have my thoughts, but wanted to inquire to the collective intelligence for thoughts....

Thanks all in advance.

[John C]

You sure the cats aren't clogged? You have three cats and when they get clogged badly you won't be able to drive more than 20 mph.

Just a thought.

[astateofmike]

No, I beleive the PO had replaced them to smog/sell me the vehcile. He took excellent care of the RRC. Again, it may be that I am used to a little more powerful vehicle. I can cruise 65-70 all day and I wheel. Its when I am going up hills she seems a bit doggish....I am used to hitting the pedal, paying the gas tax and picking up speed...my 3.5 doesn't so much.

My basis of comparrison is our 2.o jetta iv and a 4.6 vortec baby blazer...

It may just be that the RRC is running fine, she just doesn't have the same type of power.

I was told by the fine folks at WCB that I can swap out gears in the tcase I believe to get better highway speed....but money is money, so I am saving for all these things as it runs fine now....

I am going to flag down a neighbor and have him run me around in his 90 something RRC for comparison...

[John C]

Unfortunately the 3.5 is too small of an engine for a RR. I know one guy in my neighborhood that bored out his 3.5 to a 4.5 (RN did the work), all I can tell you is that the outside mirrors used to close when he hit 90mph in that thing. He also had 4.11 gears.

I think it's time for a 4.6 engine.

[astateofmike]

well then, maybe I need to look at that 4.6. Like I said, I was used to a little more torque...

Maybe I can find one laying around when the time comes. I had hoped I was missing something, just turns out I am not...

[Paul Grant]

While I'll agree with John that the 3.5L in NAS form, straight from the factory, was woefully underpowered, there are things that can be done to give some life back to your engine.

First, the 3.5L engine was notorious for eating up cams, If you still have the original cam in the truck or even if it is the second one, at the mileage you have, I'd say it was time for a new, more aggressive one.

I'd also be willing to bet that the timing chain has stretched as well. A dual roller chain will help to keep the timing right for a lot longer than the OEM chain.

Another thing that I was always amazed with was how small the manifolds and downpipes were on the 3.5L. At the very least, a pair of 3.9L exhaust manifolds will help with the exhaust flow. Better yet, spring for a paid of headers. They range in price from $135 a pair at Summit Racing to however much you want to pay for a stainless pair.

Take a look at the RPI website (www.V8engine.com) or D & D Fabricators (www.aluminumV8.com) just to get an idea of what you can do. The 3.5L isn't the greatest engine but you can get a lot more out of it than what you're getting at the moment.

[astateofmike]

Well I am not looking for blazing speed, but I don't want to run out of power. Thanks for the ideas.

Headers: sound good, look nice.....beny.
Cam....well if I need to do anything to the engine, that makes a heck of a lot of sense....

Continue, I am busy taking notes...

[Disco]

I fully agree with Paul. Time for a new cam.

[Greg M]

Take it from the owners of a 3.5, it's a bit of a dog. I just recently rebuilt mine and though i didn't bore it, it's still underpowered. Paul hit the nail on the head with the cam and timing chain. 180K is a lot of miles on any engine - regardless of how well it's maintained, and these engines eat cams and chains. Also, i can't tell from your pics or sig, but are you running bigger tires? The combo of a 3.5, 3.54 gears and big tires is just too much for that tiny little V8.

Bottom line is this - Americans are spoiled when it comes to horsepower. Ever heard "there is no replacement for displacement"?

So, it comes down to personal preference and how much your willing to do. If you have the money and know how, you can easily swap in something bigger. But for me, the 3.5 gets me were i want to go, and when i climb a nice long hill on the highway, I get a good running start, down shift, and stomp it. I can usually make it to the top still doing 60-65, but i'm sure as hell not passing anyone!

[Greg M]

Originally Posted by Paul Grant

Another thing that I was always amazed with was how small the manifolds and downpipes were on the 3.5L. At the very least, a pair of 3.9L exhaust manifolds will help with the exhaust flow. Better yet, spring for a paid of headers. They range in price from $135 a pair at Summit Racing to however much you want to pay for a stainless pair.

Paul, are you running headers? If so, do you a) thinks its made any difference in HP and b) have you sacrificed any torque?

[Paul Grant]

No headers, just 3.9L exhaust manifolds hooked up to a custom exhaust. No cats either.

[John C]

We had headers installed in my partners 3.9 RR (AdrianS) and it made a difference. If I were to compare a truck w/headers and one w/o headers it would be like comparing a truck with 4.1 gears and one with 3.54 gears. (Just a comparison)

[Paul Grant]

I've been tempted to pick up a pair of Hedman headers from Summit and then getting them jet hot coated. I know that left on their own they rot out quickly so this may be a way to make them last.

[Paul Grant]

Oh, John, how do you want to work out the transfer of the 4.2L.
Thanks,
Paul

And of course, sorry for the hijack.

[cdmbrennan]

The 3.5 is a great engine- and there is much you can do with it to increase performance. Pick up a copy of "Tuning Rover V8s" or do a search for the Buick 215 or Rover 3.5L engine- scads of information on tuning.

Crane Cams are recommended, as well...