454 for towing

[cratemodel014]

Hey guys building a 454 in a 86 chevy dually for towing a toy hauler. Figure weight of toy hauler to be around 12000 to 15000. Using the factory heads whicb are the 045's. In this application would you go to bigger valves or keep the stock size. I know I need port velocity was just curious about valve size.

[vortecpro]

I would internal balance, use a flattop Mahle piston at zero deck, the 045 heads would get a 2.125 intake valve and mild porting, the 1.720 ex would be retained with mild porting, although the chambers would be done, CCs would be set at 120. I would use a 208/218 @ .050 hyd roller on a 111 LC. You would have a different animal on your hands after these modifications.

[Alaskaracer]

Personally I wouldn't build a gas motor for towing, especially at that weight. You will get crappy fuel economy....2-5 mpg in some cases....Been there done that....

As to valves, you're better off with some very mild port work, a quality dual plane intake, and proper cam. If your transmission is an automatic (assuming it is), stay away from performance converters and stick with stock stuff unless you want to spend the money on a custom part. Stall speed is something you DON'T WANT! Hydraulic roller cam will net good gains over a flat tappet, just be very conservative. Call the manufacturers and be honest with them about what you intend to do.... While compression is usually free horsepower, it's not going to be your best friend here. I'd keep it at or under 9:1 with iron heads, and a good HEI ignition will serve you well. You'd be surprised at how much power you can actually make with a mild build from a 454, as long as you don't get into "race mode thinking" and start buying parts you shouldn't. A good Q-jet is your best choice for a carb, unless you go to a newer electronic fuel injection system. If it's already a throttle body setup, BE SURE THAT THE CAM IS COMPATIBLE WITH IT. I worked on a kid's truck that wouldn't run for shit.....cam wasn't spec'd for his injection system and the MAF didn't like it at all...we had to reinstall a stock cam to get it to run right.....

Regardless, keep it mild and conservative. You want power from about 1000-4000 rpm MAX.... that's where you'll be spending all of your time. You don't need anything fancy either, like forged pistons, gapless rings, etc.....

One last thing, make sure you put the biggest radiator in it you can fit.....don't skimp on the cooling system in any way. That thing will get hot as hell towing and needs a good cooling system to keep it alive. I HIGHLY recommend an engine oil cooler as well.....

[Truckedup]

What type transmission? The more gears the better... 6 speed manual from a late model truck would be nice...Or a 5 speed auto...

[Newold1]

I have talked to a lot of users over the years and most probably like you don't have or want to sink a ton of dollars in an older truck and engine. So first thing you need to do is establish a budget. With enough dollars anything is possible and maybe even buying a good condition later model diesel HD 3/4 or 1ton Diesel truck is in the budget with the sale of your truck.
Heavy duty towing like you are talking about needs heavy duty, engine, cooling and drive train and it needs to get some minor sort of MPG if you are going longer distances. Gas is about as cheap as its ever going to get here in the USA and if world events and OPEC cast their spell it's gonna get a lot more expensive in the mid terms.

Once you get a real doable budget get back to this thread and ask for the good people on Speedtalk with experience and knowledge and they will probably have some good suggestions and advise for you.

I will throw this out as I just had a friend with a older towing truck who just did this upgrade and he is absolutely thrilled with it. It was not a cheap budget build and he spent about $10K total getting it road ready, but that's what I mean when looking at your options. do that now before you start the project.

Here is what he did. He bought a new part #19328586 GMPP log block, the new 488 cubic inch 8.0L engine, upgraded the camshaft only (already hydraulic roller setup)to a better spec. put an Edelbrock 75613 intake and a Edelbrock 1406 carb, a set of 1/7/8 long tube headers with a nice Flowmaster 70 series muffler, rebuilt the transmission with new heavy duty parts and clutches and converter, upgraded his radiator, added a tranny cooler and all new belts and hoses, etc. Now he has a what I estimate is a 450HP, 550lb/ft of torque gas engine tow master truck. This thing pulls like a mule and he is getting about 8-10 mpg towing a very heavy boxy trailer. This would be my suggestion for staying gas. If its out of your budget, then don't start on that project, sell the truck and buy a 2003 and later diesel truck. JMO

[pdq67]

Now, I forget if this set of BBC engines were 454's OR 496's because he liked the 496.

BUT, please look up the BBC engines that the late/great JL made using big valve peanut port heads that was 9.2 to 1 if not mistaken.

He put 2.25"/1.88" valves in them and did the usual bowl-blend. I think that later he switched to using big valve -049 and/or -781 heads.

Cam was a CC 252HE and intake was a 750 dual plane. headers were small 4-tube, long tube.

He built it for his work truck and then decided to play with it.

I want to say the old article is in the mag. that has the picture of, "CHEZOOM", on it! The way custom, dark teal colored '57 Chevy!

And later, he did the same type of testing but used the newer 502 engine. There is an article on these builds too if you want to hunt them up.

pdq67

PS., JL's cam testing in these engine articles brought to my attention CC's great old 288AR, solid street roller cam that UDHarold finally made a solid flat-tappet lifer copy of for me after I bugged him for quite a while before he left us.

[Newold1]

Just an update to my earlier post. That new GM 488 -8.0L long engine, it has a forged crankshaft, forged rods, hydraulic roller camshaft and lifters, lighter weight pistons, 9.9to 1 compression, and the better flowing and chamber of the larger peanut port Vortec heads and best of all it has a real GM warranty. Tough to beat for it's discounted by some high $4K price. This engine can also be used with late model 454 engines MPI and even 1998-2001 454 trucks because it comes with the electronic efi system crank and cam sensors. Check it out.

[pdq67]

Just an update to my earlier post. That new GM 488 -8.0L long engine, it has a forged crankshaft, forged rods, hydraulic roller camshaft and lifters, lighter weight pistons, 9.9to 1 compression, and the better flowing and chamber of the larger peanut port Vortec heads and best of all it has a real GM warranty. Tough to beat for it's discounted by some high $4K price. This engine can also be used with late model 454 engines MPI and even 1998-2001 454 trucks because it comes with the electronic efi system crank and cam sensors. Check it out.

I think that it is a 496 Vortec engine, if not mistaken.

4.25"b x 4.37"s = 496. Tall deck block to boot....

The deal about it is that the newer LS- intake port style heads have their bolt pattern changed just enough that you have to plug and redrill them to fit them on a MK IV block.

Heck, install a low deck 4.350"b or 4.375"s Mark IV short block and go. I think it should be a 505"???

pdq67

[Brian P]

Towing as much as the original poster wants to tow, is a job for a Dodge/Cummins with a manual transmission (the automatics are too prone to blowing up with this sort of load on them). They are hard to find but they are out there. I wouldn't even think of towing that much with a gasoline engine of any sort.

[Newold1]

pdq67
The engine I talked about here is NOT a Gen 7 8.1L 496 engine. It is a Gen 6 BBC engine in a 10.2 tall deck height with a 4.275 bore and a 4.250" stroke. Check it out and you will see the differences. The real beauty of this engine is with a good camshaft spec. a decent intake and carb with headers this engine will make 425lb/ft. of torque at 1800 rpms and produce 550lb/ft. of torque at 3800 rpms. This where a towing engine will do all its work and the torque is what gets the job done, not horsepower at higher rpms like performance big blocks are expected to do. Heavy truck+ towing heavy loads = needs lots of torque at low rpms-- Grunt! The newer diesels do it better but they are a lot more expensive to buy, even used.

[pdq67]

I really try to keep up on the GM BBC engines and I have never heard of an engine like you are talking about?

The 8.1 L Vortec tall deck, BBC sure!

4.25"b x 4.37"s here.

And my 496" engine being a Mark IV standard deck height block is 4.31"b x 4.25"s...

Not saying it isn't out there, but I have never heard of it..

pdq67

[cfm]

Page 320

http://www.gmperformancemotor.com/media ... g-2016.pdf

[pdq67]

As stupid as this sounds, my computer can't open pdfs or youtube vids so please post a copy of the sheet for me.

Thanks,

pdq67

[Truckedup]

Towing as much as the original poster wants to tow, is a job for a Dodge/Cummins with a manual transmission (the automatics are too prone to blowing up with this sort of load on them). They are hard to find but they are out there. I wouldn't even think of towing that much with a gasoline engine of any sort.

Not that long ago trucks used to pull that weight or more were gas engines. It wasn't until about 1980 that Diesels became popular in medium trucks and the 90's for PU trucks. There are Diesel options today but a gas engine will pull at a cost of more fuel and won't last 250K miles....On the other hand, a Diesel PU truck is an 8 grand option new and higher cost used......

[cfm]

As stupid as this sounds, my computer can't open pdfs or youtube vids so please post a copy of the sheet for me.

Thanks,

pdq67

Vortec 8.0L
19328586

Truck Power with Gas, CNG or LPG
When it comes to grunt work – like pulling your car hauler or offshore racing boat – Chevrolet Performance’s
heavy-duty 8.0L Big-Block does the job like no other gas engine. It’s designed to accommodate gasoline, CNG or
LPG fuels, and because it’s a Big-Block, it delivers strong, low-rpm torque.
A tall-deck version (10.2-inch deck height) of the latest block casting, featuring full-length water jackets, thicker
main bearing webs and four-bolt main caps, is the 8.0L’s foundation and it’s used with a forged steel crankshaft
and forged connecting rods for great strength. A long, 4.250-inch stroke helps maximize torque. It also features a
crank-triggered ignition system, with 4x camshaft and 58x crankshaft reluctor wheels.
Our assembly comes with heads and a balancer installed. An induction system, ignition, starter, water pump and
other accessories are required to finish the engine. The engine requires an intake manifold designed for a tall-deck
block, such as Chevrolet Performance manifold P/N 88961161. Conventional Big-Block intake manifolds can be used
with spacers (not included).
NOTE: The engine can support fuel injection and also has a provision for a mechanical fuel pump (the production
8.0L camshaft does not have a fuel pump lobe).
NOTE: Refer to page 91 for the complete horsepower and torque testing procedures.
Vortec 8.0L
19328586
INSTALLATION NOTES
• Designed for gasoline or CNG/LPG on-highway applications
• Tall-deck block design (10.2" deck height)
• Full-length water jackets (non-siamesed cylinders)
• Thicker main bearing webs with four-bolt main caps
• Forged steel crankshaft and connecting rods
• Double-row roller timing chain
• Anodized pistons with full floating wrist pins offer
CNG/LPG capability
• Hardened valve seats (intake and exhaust) for CNG/LPG durability
• Stainless steel intake and exhaust valves for CNG/LPG durability
• Adjustable valve train
• “Fast Burn” cylinder heads for fuel efficiency and power
• 58x Crankshaft positioning sensor capability
• 4x Camshaft positioning sensor capability
• Flat-response knock sensor capability
• Coil-near-plug configuration

TECH SPECS
Part Number: 19328586
Engine Type: Chevy Big-Block V-8
Displacement (Litre): 8.0L
Displacement (cu in): 488
Bore x Stroke (in): 4.270 x 4.250
Block (P/N 19256820): Tall deck (10.2")
Fuel Requirements: LPG/CNG
Crankshaft (P/N 19300876): Forged steel
Connecting Rods (P/N 19256831): Forged steel
Firing Order: 1-8-7-2-6-5-4-3
Connecting Rod Ratio: 1.58:1
Pistons (19256829): Hypereutectic w/anodized
top ring land
Camshaft Type (P/N 12556291): Hydraulic roller
Cylinder Heads (P/N 19256827): Fast Burn iron
Damper (P/N 19256830) Cast iron
Valve Train: Fully adjustable
Compression Ratio: 9.9:1 nominal
Crankcase capacity: 8 qts
Maximum Recommended rpm: 4,500
Balanced: Internal
NOTE: Distributor with melonized steel gear MUST be used with
long-blocks and Partial engines with steel camshafts, or engine
damage will occur

Here it is on SDPC's website:
http://sdparts.com/i-24080510-gm-engine ... ngine.html