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Upgrading a stock low perf. engine no longer worth it?

B

Blazer79

1/2 ton status
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Guatemala, Central America
I have a 350 TBI engine. It's in my 1995 Tahoe, but my thoughts apply to any low performance, smog heads, engine that came stock in our K5s that you'd want to upgrade for more power.

My engine with about 150,000 miles is starting to consume oil. So I see a rebuild in the future. This engines came low performance from factory. They were designed for low-end torque and to comply with emissions regulations. My 4500lb truck feels so lazy and it's a gas hog. So a simple rebuild that leaves it the same only new is not gonna cut it for me.

So I started daydreaming about getting better heads, and cam, plus the low end rebuild. What I'm afraid I have discovered is that is no longer worth it unless it's of some sentimental value to you. I don't need to be emissions compliant here, so I'm going with the parts I would use.

First, the bottom end. A typical hyperutectic kit from summit is $237. Add $250 for the machine shop. We have $487.

The first heads that come to most of us as an upgrade are a pair of Vortecs. These run at $317.50 each which comes to $635. But then, we need to change the intake manifold. That's another $143 for the cheapest Summit manifold or $415 if you're running TBI like I do!

I still need to add a cam. My engine doesn't have provisions for roller cam, so I need to either stay with an old fashioned hydraulic cam, which is a concern due to the lower zinc content in current oils, or go with a retrofit lifter kit. A comp cams retro fit K-kit, which includes everything you need is $955.

So if we add up these parts, we have a grand total of $2,492 for my TBI engine, or $2,220 if you're running a carb. TBI probably higher due to getting a chip for the ECU or going MegaSquirt.

That's over the price of a used LQ4 6.0 engine which is basically an iron corvette engine. I know, the LQ4 means adding a fuel pump and hoses, fabricate some brackets, and either changing your torque converter or changing the whole tranny. The latter one will probably add another grand, but if you think about the extra gear you'll be saving gas. Also, if your engine is crapping out, your tranny is probably also. So you could look for an 4L80E in the deal.

I also know a used engine is not the same as a fresh rebuilt one, but chances are you get a good one that'll last for at least a few years and you can save for that engine's rebuild. I think about the LQ4s better mileage and better performance. So unless you get a deal on some aftermarket heads that don't require you to change manifold, I say it's better to go LQ4. If you're lucky or want to spend a few extra bucks you might even get an LS1. Or if you wanna go cheaper get a 5.3L which are cheaper.

Am I crazy thinking this way? Or am I leaving something out?

Sorry for the rant. I can't have this kind of conversation with my local friends. They all think I'm crazy and that I should look for a tiny Kia or Toyota diesel engine. LOL.
 
First, why is it using oil?
With today's modern oils, 150K is not all that much mileage.
Of course, one bad air filter or a leak between the filter and intake can cause lots of wear before its caught.
Otherwise, new valve cover gaskets, or other leak stopping measures are cheaper than a new engine.

That does not address the problem of being a pig from the factory, just moves the need down the road a ways.

Also, anyone else wanting to chime in, needs to notice something I only saw after starting to post.
You are in Guatemala.
Nothing wrong with that, heck its probably nicer than where I live. But it affects your options in ways I am not sure of.

Here, the first thing most folks will recommend is a crate engine. Not sure if its a viable option for you.

You might look into a combination of your ideas. Find a more power friendly used engine, with the roller cam and other things, and rebuild it.
This has the advantage of fewer changes and you can still drive the truck while you take your time with the rebuild.

Also, take a look at the gearing situation. Most of the time, going to a better pulling ratio gives you better acceleration and performance at the expense of gas mileage.
But, I have seen some factory setups that wound up with better mileage afterwards just by moving the rpms into a better range.

Obviously, going from a highway running ratio to a rock crawling ratio would not, but a one number bump might help things.
You might note your engine rpm at normal highway cruising speed, and post it along with your ratio and tire size here to get opinions from folks who have actually done it and get their opinions.
 
I'm personally looking at the LS engines more an more. The 5.3L in particular because of how cheap and plentiful they are. The LM4 throttle-by-cable is stupid cheap, $400-$600 for a low mileage unit locally and most of the time you can get the computer and harness with it.

I can wedge a 5.3L in my K5 with a 4L60E and be off in short order. Even using the throttle-by-wire engine, a few inputs wired to the computer and you have cruise control w/o servos or any of that jazz.

I'm wanting to do a turbo 5.3L in the Monte Carlo with a six speed manual. Throttle-by-wire also just because of the ease of installation with the cruise control. I want it comfy and fast as I hope to not EVER do another build. Simply play with the Monte from now on.

I've also been thinking about the new DoD/AFM 6.2/6L80E setups from the Suburbans and such for a swap into the Sierra. Major horsepower boost, better mileage and six speeds. Just have to get someone to set up a tow/haul mode in the computer to lock out the DoD/AFM when towing. I'm kinda waiting them out though, GM is having trouble with carbon build up and oil consumption on the DoD/AFM stuff right now. I'm gonna hold off till they figure out a solution for that. Right now it's a new set of pistons every 50-70k miles.... :rolleyes:
 
From what I've heard the labor on auto work is much cheaper in Guatemala, which could skew the numbers, but I think it depends on what you want to do. If you want to build a radical engine, then it might not matter so much which platform you start with, as you'll be buying heads, pistons, machine work, etc. But if you are just looking for 3-400 horsepower and good mileage, swapping to the newer engines sure seems like more bang for the buck/labor.

Plus, I know there are 5.3 trucks down there.
 
I thought all later smallblocks were machined for roller cams? Atleast the few 87 up ones I've had apart were.
 
I don't think the trucks ever came with roller cams until 96 when the Vortec V8 came out.

I dont think you are at all crazy to do a Gen III swap in your truck. I would personally reccomend a 5.3L over a 6.0L for your Tahoe though. The 5.3L will get you better mileage than a 6.0L without giving up too much power. They are cheaper to buy and easier to find (around here anyways) and allow you to use a 1\2 ton 4l60e transmission instead of a heavier duty 4l80e.

The wiring will be fairly straight forward in the 95. You can easily integrate the Gen III harness into the stock 95 under hood fuse block. The tach and speedometer will play nice with the new engine and you can just fit your stock oil pressure and temperature sending units to it as well.

A Vortec fuel pump installed in your fuel tank and a few lengths of stainless steel braided flexible line with -AN conversion fittings will have the fuel system dealt with.

All in all a doable swap
 
They didn't come with a roller cam, but they are roller blocks, you just have to drill a tap a few holes.

Martin
 
Welcome to the world of seeing the small block light. There is NO reason other than racing class limitations to use gen I small blocks anymore. The key to the budget is finding a good pull. For instance I bought a 5.3 motor, accessories, harness, and ECU from a 130,000 mile suburban for $700. When I pulled it apart it looked like it was brand new.

I simply pulled it apart because Im doing a HI-PO build in a street truck and dont believe in building power on a question mark bottom end. If you want to start going crazy its going to add up fast. Im $4000 in for heads, cam, intake already and that doesnt include things like oil pump, gaskets, machine work, new pistons, bearings etc. But Im a bad reference point considering Im shooting for a 500-550hp motor with smaller cubes.
 
My 90 sub had been drilled and was ready for a roller. Even had the hole for the fuel pump hole drilled.

Also had a 89 305 in a k1500 that had a roller cam in it.
 
So I'm not that crazy after all.

Fordum, No, it's not leaking oil. It's burning it. Unfortunately it's not a gasket issue. It's using about 2qts per 3000 miles.

Yes, Guatemala is a very nice place to live. I just met two guys from Utah who made the move and came to live with their families here.

I did consider a crate engine, but I think I can save about $1K since I can do the job. I already built my 489. I put about 600 miles on it and so far so good. Shipping is not that great of an issue. For heavy items, I ship them by sea. I just pay for the cubic feet I use regardless of weight.

I'm looking for a roller engine mostly because of the lower zinc content in the oils. If I were to chose today, I'd choose a roller cam for the 489 I built. But since I was buying parts slowly, I bought the hydraulic cam about 5 years ago. Didn't know about the differences in the new oil.

I already did a gear change on the Tahoe. It came originally with 3.07 and changed to 3.42. Maybe I should've gone to 3.73 since I mostly use it in traffic.

TerryD, I was initially thinking about the 6.0, but your posts are making me realize that a 5.3 is a very viable option. The 6.2 DOD AFM engine is waay out of my leage. LOL.

Blue85, Machine work can be found dirt cheap here. However, I do my work at a more reputable shop that's not that cheap.They have Rottler machines, and most important, they are very friendly and let me see what they're doing.

I'm not looking for a radical engine. Just something that moves the Tahoe decently. Some time ago, I got these nice wheels and showed them off to some friends. They asked me to do a burnout in that "big V8" engine. I politely declined because I knew I was headed for embarrassment. :whistle: Have you been to Guatemala?

Bowtie85, My Tahoe is made in Mexico. It's really not branded Tahoe, it's a Silverado. But I know that's a pickup truck for you. So I'm sure that's got to do with not having provisions for roller cam. Even if it's a 95. A friend had an 87 Camaro and that one came with a roller cam.

Russell, that's what I'm thinking. A 5.3 is the best option. I'll start looking in junk yards. That vortec fuel pump is a great idea.

823SS, I saw this guy on ebay years ago selling plans to drill any non roller SBC block and turn it into a roller block that used factory style roller lifters. Is this what you're talking about? Cause the only difference between this block and the 350 that came in my 79 K5 is that the 95 doesn't have mechanical fuel pump provision, one piece rear main seal, and a different oil pan pattern. I don't consider this a roller block.

Stomis, That's a great find. I hope I can find one like that. I just wish I find the latter ones with higher output. According to Wikipedia, the first ones where only 285hp. Not that much of a gain over the current 200hp TBI though.

Bowtie85, Where's the hole for the fuel pump you mention? Is it for a mechanical fuel pump?

Thank you all for your replies.
 
Any 87 up block should have roller provisions in the block. All 87 up cars should have had a roller cam. The trucks had the block just no roller cam.
 
Stomis

I took some pictures when I replaced a blown head gasket back in 2007. I see some holes in there. Can you confirm if this block in fact can be converted to roller cam? That would probably change my plan to keeping this engine and just upgrading to roller cam. :waytogo:



 
Yeah that's def a non roller block. Could do roller retrofit though?


I was talking about mechanical pumps, which doesn't apply in your case. Lol.
 
I figured it's an old style block. You had me for a while though.

Yeah I could do the retrofit, but that's when I realize that getting a 5.3 becomes cheaper, and already has roller cam and better heads.
 
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