Up to a point no, but when you start to make serious HP you need to turn the motor faster and the life of a motor is shorter. Right up to T/f that may only get a single run from a motor but I doubt your looking at 7,000+ hp....... Are you?
No kidding, those top fuel engines only last one race before a rebuild? Here's the thing. I've built engines but I want to build a keeper. A 426 Hemi, and I want to build it to last. However, I haven't built a Hemi or anything making wild horsepower and want to know about longevity. BTW, do people ever sell used 426 Hemi blocks? They want three grand at the Chrysler dealer, I know it's a pricey engine but looking to save on expenses wherever possible. What makes a powerful engine last?
1. Good lubrication 2. Balancing 3. Attention to details during assembly 4. Not revving it to the moon
if you have gobs of HP then if 1 little thing goes wrong the whole engine is toast. my civic could have a bullet hole in it and still run- but it only makes about 90hp.
no, it doesn't it depends on how the engine is driven if you had a 426 hemi or 427 ford high riser and drove it like granny, it surely would not wear out any faster- the worse that would happen is, it would carbon up the valves and ports if you drag raced it every weekend, yes, it would wear out rather quickly, in about 2 years it would need a freshening but the basic engine horsepower rating won't wear out an engine any sooner
I'd say YES based on the premise that the original factory engineers design an engine for a good balance of performance and durability. Unless you're smarter than a factory engineer, once you begin performance modifications, you are upsetting the balance. As you increase power you sacrifice durability. It makes no sense (other than cosmetics) to modify an engine and then drive it like a granny, and you won't. You'll want to test out those mods every chance you get.
The achilles heel of the Hemi in Drag Racing is Valve Springs - they change them a lot. If you have a milder cam (hydraulic would help) and keep the revs under 7k, I think you will get a lot of longevity out of an Elephant. Dick Landy (R.I.P.) built his street bound Hemis with tighter fitting pistons and positive stop collars and spacers on the rockers to tighten things up and increase longevity. It is a Mopar after all, so looked after, it will run hard for a long, long time.
In a street driven car, power use has to be very brief and episodic, so little real effect on life. Examine reality...unless car is in the power range of a 1957 Hillman Husky, you can only hold full throttle for a few seconds...unless car is utter dog, 10 seconds of full throttle should get you into speed levels of interest to the police, and 15 seconds will get you into Jail time speeds rather than a ticket. Except in Resume Speed, North Dakota, 20 seconds under full blast should also bring you within range of some slow or immovable object requiring more handling than you have at your top end...short, happy bursts and an occasional blast when it's 3AM and you you just saw the police car parked at the Waffle Pit.
No, up to the point where you exceed the design limits of the parts, or the tuning capability of the mechanic. A good example of the latter is the subject of cap walk on a 460 Ford with an OE block. You have some guys who get very little cap walk even at the 800hp mark, and others who can't keep the mains from moving, with very similar or identical combinations. The difference is often that one engine is suffering from detonation, and the other is not. To answer your question about used 426 Hemi blocks, yes, they do come up occasionally, but they tend to be severely flogged. A quick story: Back "in the day" a friend and I needed to get a 426 block for NHRA A/SA racing purposes. As Mopar Performance had not yet released the new block, we were able to get a damaged block (from tossing a rod through the pan rail, LOL). We were able to get it welded and get new sleeves installed (as in welding)....for $2400+, in early '80s money. Then the entire block needed to be remachined, as the process distorts every surface of the block. At the time it was worth it to obtain that particular block. Nowadays I wouldn't think twice about going to the dealer & spending the $3000 for the MP block....though their crate engines are highly overpriced, the blocks are a good deal. So far as keeping them together, as Just Gary & Bruce said, rpm is the killer. If you particularly want to go past 7000 rpm, then you will be spending a lot of money on rods & cranks that will last...and lightweight pistons & valves to keep the loads down. You will be best off building a large CI engine with a nice wide powerband, and keeping the rpms at around 6500 max...a street engine built this way will last virtually forever. Combine it with a decent overdrive automatic, moderate rear gears, & it might even get reasonable mpg to boot.
I have not seen your question answered this way. You mentioned a 426 but, in general terms to concern everyone reading- The larger the engine is the less is has to work hard to make power. If you take a 283 and a 502 or 571 as examples, the little motor has to work much harder ( and thus have a shorter life) than its larger brother. The larger engine does not need to rev as high to make power as a little motor does. The lower the rpm , the less strain on rods, bearing, springs, etc, etc. If you want more reliable power, I would add a 1/2" stroker kit to your 426 as the 426 has too short a stroke to begin with ( it was desigined for sustended high rpm operation on nascar tracks). A street or street strip engine does not need to rev high. Adding 50-75 inches to your motor will realy wake it up and you can also run a milder cam too. As am example, the round port 455HO Pontiac in my GTO now has over 173,000 miles on it. It still runs good and does not leak. When reliability and longevity is most important in a high performance build, You would be wise to build it big. By the way, Top Fuel engines do not NEED to be rebuilt after each run. However, they are torn down most of the time to make sure it is making absolute top power for the next pass. I know, I own and tune one. Steve www.pontiacheaven.org Hosting- Pontiac/Buick/Olds FALL FEST Sat Nov 28, 2009 Phoenix www.pbofallfest.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org
This is true to a point, but you are leaving out 2 HUGE factors in the original engineer's consideration. Cost and technology. For example, long tube headers make more power and reduce stress on motor by using pulse tuning to reduce backpressure. Mopar didn't use them because they're expensive and not friendly to production lines. The same holds true for hand porting heads. Works great, doesn't make life harder for the engine, but it can't be done at a reasonable cost "on the line." Another example, electronic ignition. It beats points everyday of the week, but it didn't exist long, long ago. If you really think about what you are doing and why, you can increase power, efficiency and longevity all at the same time.
More stroke, more rod angle (smaller rod ratio), more RPM, more bearing clearance, more spring pressure, more static compression = reduced life. it was desigined for sustended high rpm operation on nascar tracks? The stroke was fixed on 1959 for the Imperial.
diesel engines don't count, they're twice as heavy as gasoline engines... If you want to make a lot of power and have a long lasting engine, without having to deal with valve spring issues etc, run a relatively low rpm engine with a blower. much fun, not much maintenance. get anodized blower drive pulleys though, as the plain aluminum ones wear out too fast.
yes, but they are built with extremely strong components. Thats why they are expensive. In general durability goes down as hp goes up, unless you pay through the nose for really good parts and a good design. The Bugatti Veyron makes 1001hp from the factory. It also costs close to $1,500,000. All the old motors that are known for being bulletproof are dogs. I know, I have one
yup, big block chevys wear out fast...think about it...if you make a lot of hp, you're putting a lot of load on the rings, bearings, etc. (although that does not explain the cam eating phenomenon...maybe the lousy factory machine work does?)
It's funny you mention that. I happen to know why small block Chevys wear out cams. In many of the older Chevy engines, the farthest back main bearing gets lubricated by unfiltered oil. Front camshaft lobes get lubed from the main galleries and don't get oil if the galleries aren't restricted. The big blocks might have the same issue. I really don't like Chevys.
80s big blocks seem to suffer from having the lifter bores in the wrong place, among other things. Did you get your question answered?
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