Thread: 454 Towing/ Farm truck

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I have 1986 Chevy 3/4 ton with a 454 and 4.10 with a 4 speed trans otherwise known as a camper special. I use this truck to pull a tractor, pipe, etc. As we all know they are weak and wimpy in stock form. I am keeping the peanut heads because it is a pulling rig. I will also give it a performer intake and headers. I need advice in the cam department. I have built small blocks all of my life and new to the big block world. I have read that the valve guides create clearance issues above .500 lift. I would really like to run this cam:
Brand:Lunati
Manufacturer's Part Number:10110701LK
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,000-5,500
Intake Duration at 050 inch Lift: 213
Exhaust Duration at 050 inch Lift: 219
Duration at 050 inch Lift: 213 int./219 exh.
Advertised Intake Duration: 256
Advertised Exhaust Duration: 262
Advertised Duration: 256 int./262 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.515 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.530 in.
Valve Lift with Factory Rocker Arm Ratio: 0.515 int./0.530 exh.

It is a Lunati Voodoo. The lift is what I am concerned about. I plan on changing the valve springs for proper seat pressure and so on. Has anyone ran this cam on stock peanuts? Will it clear? The motor has 48k original miles and in perfect condition, I do not want to destroy it. I simply want to improve what I have.

I had a 1984 crew cab with the 454, auto, and 410 gears-needed 3200-3300 rpm to run with traffic-6-8 miles per gallon---------put about 100k miles on it ---fixed all the problems, short comings with a new 1995 Ford F350 7.3 diesel-------

JDS, welcome to the forum. Hope that you get some good advice from some of the experienced engine guys that hang around here, and that you enjoy a long stay.

I'm not an engine expert and won't try to blow smoke by giving you advice on your cam choice other than to offer that today's reformulated oils don't work well with flat tappet cams. There are several reasons that all of the OEM's have only used roller lifters for the last 20 years or so, mostly performance and efficiency factors, but the need to eliminate zinc and phosphorus from the oils to stop fouling catalytic converters sealed the deal on cams. You can run one of several racing oils (Brad Penn, Joe Gibbs) that still carry enough of the heavy metals to keep the flat tappet cam happier, but the right answer is to go roller lifters and not worry about it. There are guys who don't agree, but if you take time to really research the facts the answer is clear.

I have used rotella in all of my engines for a while as I feel like it is a much better oil than what is commonly used. Do you feel like rotella would help the cam wear issue?

Originally Posted by JDS72CHEVY

I have used rotella in all of my engines for a while as I feel like it is a much better oil than what is commonly used. Do you feel like rotella would help the cam wear issue?

We've got some guys here who swear by Rotella oil. I used it (newer roller cam engine) until I discovered that it also carries very high levels of detergents, which can cause their own problems in non-diesel engines. My opinion is that any motor oil that is rated for use on the road today is formulated to prevent plugging catalytic converters, and carries reduced levels of both zinc and phosphorus when compared to motor oils that were offered before 1990. For me, I would not spend the money to build or rebuild any engine with a flat tappet cam where roller lifters are an option. Again, my opinions and I'm not going to get into another pissing match about oils (with others here, not speaking of you JDS) defending what I've learned to be true. I've found a bunch of good information on the site, BobIsTheOilGuy - Bob Is The Oil Guy | The Internet's Number One Motor Oil Site even though it's now sponsored by Pennzoil Synthetics....

Some diesels still have flat tappet cams and I still run a zinc additive to help the tappets and cam live longer. The common rail cummins 5.9 engines have very narrow cam lobes and they start eating tappets at around 125k. The zinc additive slowed down the wear process on the ones we service.

I can not help you with your cam choice either. Maybe Tech will see this and he can probably lead you in a good direction.

That truck doesn't have cats so just run the oils that have the zinc/etc stuff and you'll be ok----There are some metering rod changes for the carb that will help and one big option is to just turn the air cleaner top upside down so it doesn't restrict the flow--------correct timing curve on ignition and hopefully you do have dual exhaust????

With the weight of the truck there isn't much that you can do to get where you want to go with the smog era engine altho a change to a complete drop out of the more modern ones will give you EFI, roller cams, ECM control -you'll just have to do a fuel pump and exhaust system and then you will get in the upper teen milage with much more seat of the pants acceleration------

Welcome to CHR:

I think the peanut ports get a bit of a bad rap. They perform well in a lot of engines and with a little work they can support north of 400 horsepower and 500 ft lbs of torque.

I echo the concerns with a flat tappet cam – I’d really encourage you to look toward a roller. The good news is that there are several kits that have just about everything you need to make the swap. Comp cams part number K11-413-8 has the cam, lifters, valve springs, keepers, and timing chain for about a thousand bucks. I’m thinking your heads are 346236 (a zillion of them produced) and in all likelihood, you will have to have them machined to accommodate anything over .500/.500 lift. The Comp cam is .510/.510 – less than the Lunati you’re looking at but still too much for stock heads.

That said, you could pull the heads and have a bit of cleanup work done to open up the intake ports a bit at the same time you're getting the spring perches machined and the heads would be fine for what you’re wanting, i.e., a torque increase. This would be one time that I’d recommend an Edelbrock Performer – part number 2161 as it is designed around the peanut port and a performance peak at 3,500RPM which is almost exactly where the Comp cam maximizes as well. If your stock Quadrajet is in good shape a rebuild and a good open air filter should be all that’s necessary there. With the machine work, new manifold, gaskets and expendables you’ll get $2,000 tied up real quick but you will definitely realize a performance increase in the idle to 3,500RPM range.

It will still suck gas like a drunken sailor downs rum and not be an acceptable freeway cruiser. As mentioned, with that much weight (and the 4.10 gears) it’s tough to have a lot of low and high end performance at the same time without spending a big bucket of money.

Have fun and let us know what you decide.

Glenn

That cam will require minimum 9.5:1 static compression ratio, which will require a piston change.

If you want to keep the stock pistons in the block, you will have to use less cam. Although flat tappets are from the last century and no longer have a place in street drivers, particularly BBC street drivers, here is a flat tappet hydraulic cam like I might recommend for you....

Crane Cams, grind number H-248-2, part number 133971. Operating range 600-4200 rpm's.
Brute low end torque, smooth idle,daily usage, fuel economy, 1200-2000 cruise RPM,
8.0 to 9.25 compression ratio advised (Your motor is likely somewhere between 8.0:1 and 8.5:1 static compression ratio.)
Advertised duration 248/260
0.050" duration 192/204
Valve lift 0.453"/0.484"
Lobe separation angle 110

This is the cam timing that the motor wants and needs. Thing is, there are no comparable hydraulic roller tappet cams that fit these numbers. Every roller cam I looked at wanted more static compression ratio than the Crane flat tappet model shown, so like I said, if you want to run a roller or more cam than I have recommended here, you will need a piston change.

.

A change to an OD trans can help-you didn't mention if it was 2 or 4 wheel drive-------

Gas mileage and rpm are not a huge factor being that it is a farm truck and it might be used 2 times a month. I rarely take it over 50mph as the back roads are to ruff with a trailer loaded with a tractor and 4 wheeler. It's a two wheel drive truck, just something I can pile the weight on without being overly concerned. If it was an everyday driver things would be much different.

I do agree with all of you on the cam wear issue. I think at this point I will just do an intake and headers plumbed into the dual exhaust. Should help it out a bit.

Are you still running the factory enclosed air cleaner??????

No, it was filed away in a special place along with the rest of the garbage smog junk.

My 84 didn't have smog stuff---------but it was a 1 ton single wheel crew camaybe heavy enough not to need smog
A square bore carb/manifold ( not quad jet) of 800+ cfm will let you do more on primaries before secondaries open and will save a lot of gas--------