Waking up a tired 454

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by 93BURB, May 30, 2007.

  1. 93BURB

    93BURB New Member

    In lieu of a rebuild which I know will be in the relatively near future, what are some of the things you have done to wake up your Tonawanda 454 (mine's a 93 w/ 170,000 miles)? Intake and exhaust is pretty standard, but what else has worked for you?? Any assistance is appreciated!!
  2. Cableguy

    Cableguy New Member

    Ah this is right up TrailLeadr's alley. He just did his and will have tons of advice...Wait for it...Wait for it...um Patrick...
  3. TrailLeadr

    TrailLeadr New Member

    Well now, seems Jamie kind of put me on the spot here...lol

    I actually didn't do anything prior to my rebuild. I kind of forced myself into my rebuild.

    If I were going to do mod prior to a rebuild to get some exrta juice out of my beast. I would go with roller rockers. They're not too labor intensive, and only require the valve covers to be removed.

    Just make sure you get the right studs. I made the mistake of taking what I read (everywhere) that my heads would be 7/16 studs, when in fact they were 3/8's. So I spent a lot of time drilling and tapping my holes.
    Also because I had snapped a couple of the old rocker bolts in the head so I had to drill them out anyway.

    That's about all I can think of right now that's fairly easy, and quick hp increase. I did put in a high torque cam, but that was part of the rebuild, and I wouldn't suggest doing that without the rebuild. I found that when I pulled my old cam I had two cracked cam bearings. If you get that far, and find you have bad bearings, then you just earned yourself a trip to the rebuilding area of your garage.

    Your engine also has a poly coated aluminum timing gear on the cam. I suspect it's to help dampen the vibrations. problem is that over time the steel chain wears down the poly coating, which allows your timing to float.

    I know it's hard to say, but how tired do you think your 454 is?
    Do you tow anything?
  4. 93BURB

    93BURB New Member

    Good information, I hadn't considered roller rockers as a quick upgrade. I do have it on my list of things to do during the rebuild but it might be a good idea to go ahead and do it now!

    As far as how tired I think the 454 is... It starts right up, idle's great, and has good acceleration while not towing. When I hook something up to it, it has relatively good acceleration getting to 50 mpg but struggles a bit getting from 50 to 70 (3,500 lb trailer while loaded is all I've towed thus far.) It's not horrible by any means as it still has a bit more power than my rebuilt 350 that I had in my 87 K1500 that I just got rid of.

    I used tired in the sense that it has 170,000 miles on it and I have a small leak coming from the oil pan. I plan on putting a new pan gasket in in a couple weeks, but who knows what happened before (as if someone could have ran it low).

    Plan is to get 2 years out of the motor in its current condition (at about 10,000 miles a year) before a rebuild. That should put me in a spot that I can spend what it takes all at once and get it done in a couple months (from start to finish). I'm just looking for something relatively quick and painless that I can do to get some more juice out of it until I yank her out...
  5. TrailLeadr

    TrailLeadr New Member

    Oil pan gasket is no small chore.

    Because it's a 454, and because it's 4x4 you need to decide how you want to tackle this. You have two options available to you, both suck.

    Either remove the front axle, or unbolt the engine from it's mounts, and lift it. Either way the oil pan is not going to come out unless you do one or the other. Even at lifting, I think you'd still need to unbolt from the trans because you won't get enough lift with it bolted on.

    Of course you could drop the pan a little, and slide a new gasket into place and hope it works out that way, but probably not the best idea.
  6. 93BURB

    93BURB New Member

    Yep...that was the plan, unbolt the motor mounts and unbolt the tranny. I've also thought about saying screw it and paying someone to put it in. It would be sooo much easier if I had access to a lift!!

    Thanks for the help TrailLeadr, it's much appreciated!!
    Last edited: Jun 1, 2007
  7. TrailLeadr

    TrailLeadr New Member

    I'd be afraid to see what the bill would be for an oil pan gasket, if you had someone else do it.

    Got an extra $2000 kicking around? Get yourself a two post lift from Harbor freight.
    http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46299
  8. 93BURB

    93BURB New Member

    I like it!!

    I have a guy that does stuff for me pretty cheap...quoted me at three hours labor which isn't bad...I'd pay $175 to not have to deal with it!
  9. Cableguy

    Cableguy New Member

    Some jobs are just not backyard mechanic material, your right. More aggrevation than its worth.
  10. Cableguy

    Cableguy New Member


    See did I lie! TrailLeadr is a wealth of info...He's my hero, Damn it! LOL
  11. TrailLeadr

    TrailLeadr New Member

    At that price it's worth it to send it out. Let him deal with that headache.
  12. 93BURB

    93BURB New Member

    I just might do that...but I really enjoy working on my own vehicles. Really looks like it's going to be a b*tch though...I think I can farm out this one.
  13. TrailLeadr

    TrailLeadr New Member

    I actually had a leak on mine, and I put it off forever because I'm too cheap to send it out, and too lazy to go through that much work just for a gasket...lol Besides it was a minor leak. more like an ooze, than a leak.

    Thankfully since I rebuilt the engine, the gasket was easier to replace.
  14. tbplus10

    tbplus10 Moderator

    Along with roller rockers and a new pan gasket heres a list of items I recommend for recon on high mileage vehicles:

    Use an intake/injector cleaner to clean the top end and injectors (I'm partial to Seafoam, but whatever works to acomplish the job).
    Use a good oil additive/cleaner for a few miles, then change the oil.
    Pressure flush the cooling system, add Water wetter, and clean the puke tank out.
    Clean the MAS with CRC electronic contact cleaner (or similar product).
    Change the airfilter and wipe out the throttlebody, intake plumbing, and airbox (use an old toothbrush to get inside the TB).
    Do a tune-up. Plugs, wires, cap/rotor, and Check the timeing.
    Pressure flush the transmission (Probably have to be done at a shop).
    Change both diff fluids.
    Change transfer case fluid.
    Flush the power steering pump and system.
    Lube every fitting you can find on the chassis.

    Dont: use synthetic oil when you change the fluids, they'll possibly cause leaks on high mileage vehicles.

    I've been using this recon list for years on resale vehicles I turn, its from a dealer that only sells cars they can offer warranty on so its pretty in depth. I've never had problems come back on me and some of the maintenance items give a good indicator of the vehicle condition.
  15. 93BURB

    93BURB New Member


    Great information Tim, thank you!!
  16. Sawfish

    Sawfish New Member

    I had a similar "tired blood" problem with my 1993 Tonawanda 454, but mine started when I bought it new in 1993. After numerous trips to the "stealership", I was told repeatedly (1) We never heard of that before; (2) Unable to duplicate customer complaint; and (3) Vehicle is within specs..

    After relating these woes to a friend, he suggested that I have it dyno tested. I explained this problem to the dyno techs, and they told me that what I described was not possible (acceleration to 50 mph, then a leveling off of power). I told them to test it anyway. When I returned, they showed me the readout, and apologized, as the readings were exactly what I described.

    Turns out the distributor was defective from the factory. It was not all of the time that I wasted with the dealer, GM, etc, or the fact that I had to pay for the testing and repair for Chevy's mistake out of my own pocket, that ticked me off. Rather it was the fact that I did not learn the cause of the problem until 92,000 miles. Old Blue just turned over 160,000, is still going strong, and running better than when it was new.

    I strongly suggest a dyno test before embarking on expensive repairs. It was the best money that I ever spent.
    Last edited: May 27, 2010

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