Safarifriends.org

Have a 1998 Trek 2480 with the 454 7.4L Gas engine. Cracked the driver side exhaust manifold all the way around. The question is should I replace the manifold or go with the Banks system with headers?

Here are some thoughts...Ask me how I know...I was a Ford 460 hot rodder in a 1 ton Ford Super Van. By all means do the headers but that is not all. There is a package of things to do to make it really work efficiently. It takes effort and some time but oh goodness the results are amazing. Fuel mileage can definitely improve, as long as you drive appropriately.

How many miles on this engine? To do change the carb to a Holley Economiser if still available. It is a 4 barrel but with progressive linkage. Most of the time it can run as a 2 barrel. Once everything is completed have the rig dyno tuned and jetted under load. On a 302 ford it went from 85 hp at the rear wheels it ended up at 105. This procedure is worth every penny it costs!!! Install heat dissipating plates under carb 2 to 4

Heads. spending money on them is very beneficial. Be sure they have hardened seats for the valves. Casting numbers read by a knowledgeable machine shop can answer this question. Freshen the heads with a valve job. It might only be a re-lapping of the valves for a good seating of the valves.

Wrap the exhaust headers with fiberglass exhaust wrap from any of the auto parts stores or Summit racing. It keeps the heat where you want it AND OUT OF THE ENGINE COMPARTMENT.

Install a larger exhaust system at least 3 inch larger not necessary. If you want this baby to breath which is where power comes from. Doing headers and nothing else is pouring good money down a rabbit hole, spend the money for an OEM manifold

Please let us in on what you do.

davidlip wrote: ↑Mon Nov 11, 2019 4:59 pm Have a 1998 Trek 2480 with the 454 7.4L Gas engine. Cracked the driver side exhaust manifold all the way around. The question is should I replace the manifold or go with the Banks system with headers?

Dave,

I don't know what is enclosed in a Banks Power system that you are looking at, but usually most see noticeable improvements. So, you plan to keep your Trek for a long while, it might be worth while to upgrade since the manifolds need to be replaced. Let us know how you make out...

David,

Welcome.

Part of the answer depends on you and your use of the coach.

Yes, if this is a long-term coach, certainly worth spending $$ on upgrading.

1998 should be a Vortec 454 (unless they had a chassis sitting around for quite a while). That is a good thing compared with earlier 454's.

Banks is excellent equipment, but there are quality headers for a lot less $$. Depends on your budget and goals.

Brett, would this be fuel injected?

Bill Edwards

We still don't know the exact year of the motor/chassis.

But, assuming a 1997:

https://itstillruns.com/74-vortec-engin ... 85310.html

The 7400 Vortec V-8 GM engine has 454-cubic inches and was rated at 290 horsepower at 4,000 rpm. It had 410 torque at 3,200 rpm. The engine has a bore and stroke of 4.24 inches x 3.99 inches. The valve train has an overhead valve, ohv, configuration with two valves per cylinder. The engine has multi-port fuel injection for induction of fuel.

RSBILLEDWARDS wrote: ↑Tue Nov 12, 2019 2:46 am Brett, would this be fuel injected?

Bill Edwards

Bill,

The Chevy 454 was fuel injected throughout the nineties. The question is, was whether the original posters engine was multiport fuel injection or throttle body fuel injection. Multiport began in '96 as a Vortec 7.4L, so as Brett said, unless it was an older left over chassis, the engine is very likely the multiport fuel injected Vortec 7.4L (454ci) engine).

BTW, long ago, my '92 Winnebago had a throttle body fuel injected Chevy 454. Was not too bad on fuel if you knew how to drive it, but it was a light, low end, 27 foot class A. (9-10.5 mpg)

Chevy 454s have long been known to crack cast iron exhaust manifolds. Our previous 1984 motor homes drivers side 454 exhaust manifold also broke. Definitely go to tube headers and use insulating wrap especially in the area of the starter solenoid. Just looked at the banks site and see the sell a oil filter heat shield and a starter heat shield (I had to make one on the road out of a bean can) that might be in the full kit.

Had the same thing happen on my previous rig with a 454. I ended up installing Thorley Ceramic coated headers. Added fiberglass heat guard sleeves over the plug wires/boots, and a wrap around heat shield on the starter. My seat of the pants accelerometer said the engine had a little more umph off the line and was a little better on the hills. Never worried aboutcracked manifolds again. One thing to note is there are two types of Thorley headers for 454. The cheaper one is for trucks and the other is specifically for RVs and it uses thicker material. This was about 6 or 7 years ago so things might be different now. I've read that you should NOT wrap ceramic coated headers.

I found the cost to be not much more than replacement manifolds.

Tom M
1998 Serengeti 3706

Years ago I had a 1984 Monaco MH with a 454. One of the plug wires went bad and as that cylinder dupe raw fuel into the header, it overheated and cracked it. Buying another cast iron header for around $250 at the time didn't seem wise as the same thing was probably going to repeat itself. I bought a set of Doug Thorley headers with all the pipes and muffler to renew the whole exhaust system for around $800. It didn't change my mpg much but it had better performance during the rare instances when I pulled out to pass someone.
Banks makes a mighty fine header system if you've got plenty of money to spare. Myself, I'd check around for alternatives.
https://www.summitracing.com/search/bra ... e/7-4l-454
https://www.amazon.com/Doug-Thorley-Hea ... 009OZA5J8/
https://www.amazon.com/Hedman-69120-Che ... 000COD39Y/
or Banks:
https://www.summitracing.com/search/par ... /tuned/yes