Cost comparrison...Swap in power or build up an IH engine?

[Mike Moore]

From another thread, regarding performance SV engine vs swapping in another engine for performance:

Originally Posted by John Donnelly

Just once, in all the years of talking IH engines and trucks here, I would love it if someone would post up an itemized list of what a conversion cost, and someone else would post up an itemized list of what their performance IH cost.

I've tossed the ideas around in my head for some time, and made my decision. I read today that others are wondering which would be the most cost effective way to go. I'll start with what I decided, and why...and where I am at in the process. Hopefully others will chime in with opinions, too.



I've went the way of the SBC engine, recently gathering parts for the conversion. So far...

$625...1997 Trans Am LT1 engine, computer, fuel tank with pump and sender, all wiring from the engine, dash, etc.
$100...1990 Blazer 700R4/NP241 combo. Tranny needs rebuilt, so it may not count.

To-buy-list:
$600...Rebuilt 700r4 and torque convertor with 1 year warranty.
$1000 (???)...a couple gauges, metal to fabricate motor mounts & tranny mount, driveshafts, exhaust, etc.
TIME...but it's a labor of love. If I was worried about time, I'd go buy a new truck anyway.

I am going to try to use the T/A wiring to get the engine going. I will need to buy a few more things along the way, no doubt. But...When finished I will have a reliable, stock, unmodified, fuel injected engine that any parts place can help me find a starter, alternator, water pump, plugs, etc for, off the shelf...all coupled to a proven, freshly rebuilt 4 speed autmatic overdrive transmission, and a 2.7:1 ratio low range transfer case. This engine put out 285hp and 325 ft/lbs in the T/A with a fairly restrictive exhaust and intake. I figure 300hp is a good guess with dual exhaust and a free flowing intake in my Scout. So, I figure my cammed 304 makes about 150hp...about half of the LT1. Now figure my TF727 has a 2.45:1 first gear ratio, and the 700r4 has 3.06:1. Acceleration should be a fair amount more brisk, I'd say. So, there's performance summed up.

Now let's talk about long-term costs, in both fuel mileage and maintenance, in that order.

Thge LT1 was rated at 17 MPG city, 26 MPG highway in the Trans Am, so in the Scout the fuel mileage should still increase substantially over the 10-ish I get on the highway with my cammed 304 currently. Especially when the 700r4 has a 0.7:1 overdrive ratio, making my 3.73 rear seem like a 2.61 when I drop it in 4th at speed. So, guessing I can easily get at least 15 MPG highway (probably more like upper teens or 20), that will be a 5MPG increase...at 10k miles per year, means it will use 667 gallons with the LT1, vs 1000 gallons with the 304. At $3 per gallon, that means I'll save $999 per year in fuel alone...while making double the power, remember. Go build your 304 to 300 horses, and let's compare fuel bills. I don't think I'll want to trade.

As far as maintenance, the LT1 I bought has 120k miles. It ain't no spring chicken. I'm sure sensors, etc will go bad, however it was running well before it was pulled and sold to me. No leaks, no burning oil, etc. Normal wear parts, like starters, alternators, etc, will be close in price to the SV, I'd imagine. The distributorless ignition (OptiSpark) is known to be a weak link in the LT1's, but can be had for about $200. Otherwise I don't know of any real problems known with these engines. I know many of the sensors aren't cheap, but when saving a grand a year on fuel, I can afford a few of these along the way.

I also should mention that the LT1 weighs in at around 560 pounds with it's aluminum heads, aluminum intake, etc. The 304 is around 700, with the 345 and 392 hitting 725 and 765 respectfully. A fair amount of difference.

So, in summary, I will have a 120k mile engine in my Scout, not a freshly rebuilt one. But it will have twice the power, be considerably more fuel efficient (hopefully), have a better aftermarket support and replacement parts supply, and it will just plain have a higher cool factor than an IH powered truck, in my opinion...and it will cost me pretty doggone close to the same as a properly rebuilt 304 or 345 would. After 2-3 years of moderate use, assuming the catastophic failure doesn't happen, it will have paid for itself in fuel alone.

After a quick look, I found a TBI system for an IH SV for $1215, and an adapter for the 700r4 behind an IH SV for $525. You'd still need driveshafts, tranny mount, TV cable stuff, likely exhaust rerouted for the 700r4 clearance, torque convertor, etc. I think I am going to be getting by cheaper with my LT1 swap than if I'd went with EFI-ing and overdriving my 304. Plus I seriously doubt the 304 would be building the power of the LT1.


So, John and others...there you go. I don't have all the numbers and prices for each individual part and piece at this point, but the major pieces are there. The above listed prices add up to $2325...I know other stuff will pop up, but if I get it done for under $3k total, it's paid for in 3 years or less, from only money saved at the gas pump.

Maybe I'm wrong. Maybe I'll regret it while I'm sorting all those wires. Something tells me the first time I stomp the pedal I'll forget all the trouble it was...then I'll remember the fuel mileage increase, too. So, bring on the arguments and let's see where this thing goes. I've got my helmet on and I'm ready.


WHAT I'VE SPENT SO FAR, AS OF 3/31---Completed swap:
I will keep this updated as I buy more stuff for this project.

-$625 Engine, wiring, radiator, fuel tank/pump, etc from the Trans Am
-$100 NP241 transfer case and bad 700r4 transmission for core
-$560 Reman 700r4 with all current upgrades and new torque converter, 1 year warranty
-$300 Computer and wiring mods
-$150 Starter, exhaust manifold gaskets, valve cover gaskets, plug wires
-$40 Throttle body to work with 700r4
-$18 700r4/LT1 TV cable bracket
-$36 LT1/700r4 TV cable
-$26 A/C delete pulley
-$25 Engine mounts for SBC
-$21 EGR block off plate and gasket set
-$80 700r4 stand alone lock-up kit
-$161 Trans fill/dipstick, K&N air filter, throttle cable, valve cover breather, radiator hose adapters
-$33 Oil, filter, heater hose elbows, fittings, crankcase vent
-$85 Custom power steering line
-$384 Tom Woods rear double cardan driveshaft
-$46 Misc radiator hose pieces and parts
-$40 Shifter, cable, brackets
-$125 Water pump (leaking when I got it running)
-$300 New 2.5" dual exhaust
CURRENT TOTAL...$3055

Stuff I already had, that I'm using for this swap:
-Flywheel
-Metal for mounts and tranny crossmember
-External transmission cooler---Didn't use it
-Mufflers

[71 Scout 2]

Sounds like you have some realistic numbers and real world goals. Maybe keep your receipts and after everything is done and said see how close your estimate was.
No arguments here. There is a lot of truth to what your statement says. I'm sure the FI guys will chime in and tell you to do some junkyard shopping to FI the SV for cheap (which is a valid point). Other people might chime in and say your 304 was tired or out of tune. And honestly 10ish mpg on the highway is pretty low.
Kept in good service that LT1 should give you 40k+ more miles of daily driving.

[Colin Rush]

I dunno, my rebuilt 304 was right around $2K, with the parts hot-tanked for me for an extra $50. And I don't have to fab anything to put it in (still putting it in, actually). It was getting about 20 MPG on the highway in my '67 1100 pickup before I rebuilt it.

If mileage was what you wanted, I suspect recamming your 304 would have been the way to go to get the mileage back down to what you wanted. That was what I was going to do before I took my engine apart and saw some other damage caused by my broken cam and timing gears. I think I had less than $300 in a cam, lifters, and timing gears at that point.

I still don't see the advantage.

[R290]

I too looked at all those options, I found a complete 5.3 motor/tranny/wiring/cats/computer from a 2001 Suburban that was totaled. Motor was stored for several years and not used, so they were looking to sell it. It was a doable swap, just needed a different radiator, exhaust, ect. I figured with the motor and parts about $3k to make the the swap. The guy sold it before I made a decision. Found a 1991 Suburban GM goodwrench 350 low miles with the 700r and Np241 for $1000, if I pull it. There were a few things I did not like ( it was a qt low on dirty oil) I offered $900 and he said no, so that motor never made it into my Scout. I looked at diesel and found a new and few used engines, but between the weight and the cost it was not going to happen. Kick'en my self as 2 years earlier I had a 95 dodge diesel I could have had for 2K complete, as it was side swipped. At this point I have tried 3 IH engines with each one having a different major problems. So I decide to have the 345 rebuilt. All stock except some mild head porting to remove the exhaust air injection hump. As for Cost, it was a lot more than I thought it would cost. Started out at about $2,800 for a rebuilt engine ( that was put together with care, plus the heads and block decked), but I wanted the heads porting for $225. Had the rotating assy balanced don't remeber exactly, but let say another $200. Had to replace all the exhaust valves at $22 each, can you say another $200 bought new plugs, syntentic oil, new t-stat, water pump, can you say $200. Oh wait the rebuilt oil pump, and harmonic balancer, another $200 bucks. Damm this is getting expensive to say the least. I could have bought new dirt bike by now and just need to put gas in it. So in the end its like the movie War Games " it's best not to play"

It's not about cost. It's about what you want. I'm a major tight wad and it took a while to save up and spend it on the rebuilt engine.

As for power, I'm shooting for 600hp, with 10lbs of Nitrous
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[Mike Moore]

Originally Posted by Colin Rush

I dunno, my rebuilt 304 was right around $2K, with the parts hot-tanked for me for an extra $50. And I don't have to fab anything to put it in (still putting it in, actually). It was getting about 20 MPG on the highway in my '67 1100 pickup before I rebuilt it.

If mileage was what you wanted, I suspect recamming your 304 would have been the way to go to get the mileage back down to what you wanted. That was what I was going to do before I took my engine apart and saw some other damage caused by my broken cam and timing gears. I think I had less than $300 in a cam, lifters, and timing gears at that point.

I still don't see the advantage.

Mine has some carb related issues, I think. I've rebuilt it 2 or 3 times to no avail. Nobody could tell me what was wrong. I got fed up with it. At 62k miles, the 304 wiped a cam lobe. No reason that I found. I put a Schneider in it and it runs good...when it runs right and the carb (???) isn't acting up. So, fixing my carb issues (I don't like carbs...in case you can't tell), better MPG, and more power were the main things I wanted.

I'd say...wow!...to your 20 MPG in the '67. That's awesome. Mine's gotten about 14-15 highway at the very most when it was first put on the road with the stock cam. It has 3.73's in it with 31" tires. Highway to me is 75-80 MPH, too. I don't think my mileage was too far off from what it should be...I don't think.

So, according to your figures, I'd have to put $300 in a cam swap, $225 in a good carb, plus misc gaskets, jets, etc. Figure $550. I'd still have a less than 150 hp engine that wouldn't run right at different altitudes, angles, etc. $550 to get it restored back to 1970's technology. I'm not saying I'm not on a budget...believe me I am...but I've got more in this Scout now than I should...why stop now?

I don't mind fabricating the mounts and etc's to make the LT1 work. Having to work at something that will make me happy is a big part of what almost keeps me sane.

I guess what it boils down to is this...I'm going to be happier with the swap than I'd be with an IH engine. A bonus is that I think in the long run it will be less expensive for me.

Does anyone think that a reliable, daily drivable, cool running, smooth idling, 15-20 MPG-gettin', 300hp IH engine can be built for $3k? I haven't priced parts and machine work for an IH engine, but I don't think it can.

[John Donnelly]

Originally Posted by Mike Moore

Does anyone think that a reliable, daily drivable, cool running, smooth idling, 15-20 MPG-gettin', 300hp IH engine can be built for $3k? I haven't priced parts and machine work for an IH engine, but I don't think it can.

3K? I bet you could get close.

And if the same work is done on an SOB brand engine to achieve the same numbers, you will spend the same money.

FWIW, the baselines of both buildups need to be identical. Just because a bargain runner EFI small block was found in the local nickel ads for a bargain price does not constitute good numbers for a cost-comparison. Any armchair estimating on costs invalidates a comparison. All items must be the same. All parts need to be comparable. If you have a forged crankshaft in the IH engine, the crankshaft in the SOB engine must be the same... get the drift? If you use a pulled-out engine, the IH engine needs to be a pull out in the same condition mechanically. Savvy?

I applaud you for at least trying to put out some numbers to give an idea what an SOB swap can cost.

In the end, it doesn't demonstrate that SOB is cheaper or better... yet. OH... and don't forget your labor. Labor should be calculated by the hour, base on current price-per-hour guidelines just like a shop would charge you.

-John

[ihslave]

Mike-

Well, I'm not here to lob shells... but here are some things to consider;

I think your estimates at a rebuilt 700R4 and TC that can handle the load of anything IH is a little low. In my neck of the woods it would be. Plus, wasn't a 1990 700R4 essentially a testbed at that point? I thought I've read that they have gone through many changes and upgrades... which =$$$.

And your $1000 to cover driveshafts and exhaust and a random guess at variables, including gauges. I built my own dual exhaust with crossover pipe, the mufflers and mandrel bends and mounts came to about $400 IIRC (but it IS *****in'). Again, my neck of the woods, driveshafts aren't cheap... but I also recall that one of the vendors would make you any length shaft you wanted at about $200, so $400 plus shipping... you're already well into your $1K, and that's just in the stuff YOU KNOW.

I take umberage with your assertion that the LT1 will be getting better mileage with better acceleration and more power.

Your LT1 already has more cubes... which means it consumes more every stroke. It also (I'm guessing) makes its torque at a significantly higher rpm... so it's going to have to wind up higher and longer to get the rig rolling. While you may see better acceleration, it won't be at a fuel savings. I agree it may feel crisper with throttle response, as is often the case with Multi-point Injection, but I'll bet actual 0-60 won't be night/day different... but if it is, again, it won't be at a fuel savings.

And, your Trans Am body is what helps the mileage at cruise more than anything. If you go to fueleconomy.gov, you'll find that virtually every long, four-door sedan gets its best mileage with a V-8... which tells me that a big engine using its torque against low resistance does the best. And scouts have LOTS of wind resistance, regardless of the engine pushing it down the road.

I'm looking at literature that states in 1972, a 304 with a 2bl carb made 147hp @ 3900rpm (which, by the way, it can run at all day long) and 240lbs @ 2400rpm. That's only 45lbs less than your SBC... and I'll bet 1000 rpm lower.

Anywho, I think your idea of doing a complete engine/drivetrain swap is the way to do it. And you're definately right, you'll have more performance options! I think your real advantage will be in having so many tuning options... I don't think you'll be getting tire burning performance and double your mileage, but you definately can play with it a lot, particularly with fuel mapping. You can program your system to be stingy on freeway gears but have lots of stoplight-to-stoplight umph!

In any case, congrats and thanks for informing us all... I look forward to seeing your progress, innovations... and results!

Merry Christmas!

scott

ps- build your SBC to run at its stated redline consistently, and look at the cost... I don't think I'll trade you, either.

What are you going to do with that worthless 304?

[Russ McLean]

Originally Posted by John Donnelly

OH... and don't forget your labor. Labor should be calculated by the hour, base on current price-per-hour guidelines just like a shop would charge you.

-John

If that were true, I could not afford to maintain my fleet. My "free" labor for vehicle and home repair has allowed me to do many things that I could not otherwise afford.

For instance money saved allowed me to buy a ReNEWed 392. I did the install.

Russ

[ihslave]

Are there any 300hp engines getting 20mpg?

[Carl Wiese]

Originally Posted by ihslave

Are there any 300hp engines getting 20mpg?

My roomate's Dad's Cummins makes 325 HP and will get 21 on the highway.