Built race spec motor reliability for street use???

[Bohn101]

I'm looking into a seriously built bike and have some questions for those who know. I've searched some forums and thought I'd ask you guys.

Lets say you come across a motor that has had serious work. Bike is super clean with 3,000 miles on the motor and is:
-Bored +2mm, sleeved and plated
-High grade 2 ring pistons, rods and cams
-High 14:1 ratio

If the bike isn't tracked and has short interval oil changes (1,500-2,000 miles). Will the bike last as long as a reliable stock motor? Before you say, "Obviously not", will it be close? Could one get 30,000 miles out of a motor like that if it was built correctly? Would it be worth spending more on a bike with similar specs vs a run of the mill stock bike? If so, how much (assuming the original build with labor was $5-6,000)? How do you take care of it? As in, do you let the bike start and idle 3 minutes before riding it?

If you'd like to share, how long a motor like this would last in a track use settings I'd also like to know that.

How many miles does an HRC race spec motor last for normal street usage?

As always, thanks for your input!

[JetFireRR]

From the info you've provided thus far: Don't do it.

If the motor was built to true "race-specs" you will be lucky to get 2k before needing a rebuild even with street use. These types of motors are not designed for longevity!

If it's a heck of a deal; buy it and part it. Find yourself a stock or lightly modified engine and swap it in for street use and sell the 'race' engine. Use that money for suspension if it that hasn't already been done.

Save yourself the headache; Competition spec engines are pretty much useless on the street and cost a lot to maintain.

Oh, not even close!

[d207gp]

You'd also need to run premium fuel, if not straight race gas. The high compression would make it ping like a mo-fo on anything less.

[Bohn101]

Damn, that is heart breaking response. I'm not super surprised by it though.

I spoke with the engine builder. I asked about the reliability of the motor, things like valve clearance inspection intervals. He said the top end was pretty much stock and for street use, the maintenance intervals and reliability would be about the same as a stock motor. He did say that if it were raced, it would be much more like the 2k miles you mentioned.

What happens if you don't rebuild the motor? Do you just loose a little HP, or is like the rings completely fail and total loss of compression?? That's crazy to me that you can spend that kind of money on great components and a motor will only last such a short time.

I asked the owner if he'd allow us to meet at a shop so that I could pay for a dyno run to see current power (this was to actually verify engine work has been done oppose to taking peoples word). I figured if it was still putting very close to the 170 HP to the wheel it would indicate a good motor with work done. I'm around 5,000' here. It's also fitted with full Akropovic and a power commander. Does it matter if it wasn't raced and is still strong at +3,000 miles?

Thanks for the response, more are welcomed!

[Jmnismo]

Originally Posted by JetFireRR

From the info you've provided thus far: Don't do it.

If the motor was built to true "race-specs" you will be lucky to get 2k before needing a rebuild even with street use. These types of motors are not designed for longevity!

If it's a heck of a deal; buy it and part it. Find yourself a stock or lightly modified engine and swap it in for street use and sell the 'race' engine. Use that money for suspension if it that hasn't already been done.

Save yourself the headache; Competition spec engines are pretty much useless on the street and cost a lot to maintain.

Oh, not even close!

Sadly, I'd have to agree with him.. I was also put in the same situation as you, and found a killer deal on a race engine! After doing research it pretty much came down to exactly how much the motor was being pushed, as in how much more compression, how much higher was the rpm taken up to, and of course how much care was taken when assembly. Since it only takes one little nut torqued correctly to cause catastrophic loss I turned it down. However on the brighter side, I've seen 175+whp cbrs go for 10,000-18,000 with no problems yet.. It really comes down to, if you like that feeling of every time you throw your leg over the bike and wanna go, if it'll start or if today will be the day it lets go..

It's tough man, if your cool with your bike possibly being down for half the riding season and have money to throw at it.. Then go for it! But I'd say a good ol factory motor with researched bolt-ons, good tune (not just afr tune but ignition as well), and great maintenance will always take you far with decent numbers..

Sorry for the novel haha

[MrDude_1]

with the race rings... its not going to last more then 15,000 miles before it will be burning enough oil that you NEED a rebuild..

[Bohn101]

I hate this forum, and I hate you guys!!

J/K, I've got to believe in my heart you're all doing me a favor.

Here is the bike that I'm interested in. I just want to make sure you're all sure that I should probably pass. I do want a ridiculously fast bike, but I don't want to be putting any $$$ into it other than standard maintenance. So we'll see if this changes anyone's minds.

http://denver.craigslist.org/mcy/3336159023.html

[Sti2.5ldohc]

That seems to be the nature of building any motor. You lose longetivy.

[Jmnismo]

Definitely a nice bike! I'd just be careful

[JetFireRR]

Clean looking bike; Still wouldn't buy it for street use as-is.

If you have the cash to spend buy something that will last. This will not!