KOZ RACING
New member
After wining a race and the motor gets completely tore down. Only a couple of races on the motor what would you do when putting it back together? Thanks
Tear Down
- Thread starter KOZ RACING
- Start date
If it only has a couple of races on it, and is a stock class engine, just lap the valves, new springs and headgasket, check everything for wear and replace anything that is showing wear accordingly. I would normally replace the rod also if it has more than 5 races on it when torn down, but with just a couple races i dont see a need to replace the rod in your case.
KOZ, I would agree with the advice offered by Weddle, with one exception .....
On customers motors, I have a standing rule that anytime the rod cap comes off, it gets a new rod ... maybe overkill, but in my opinion, cheap insurance considering the price of a rod (less than $10)
Now on my personal motor I would probably reuse the rod, BUT at minimum I would replace with new rod bolts.
Then as Weddle stated ... lap the valves, check/replace springs, new gaskets ... good to go !
Just the way stoney does it .... others may not agree .. but they should !!
KOZ RACING
New member
Thanks guys
I 'mostly' agree...w/caution/concern! When re-placing the Rod, make sure you go thru the 'normal' checking/measuring routine and don't just simply replace it. Also @ $15+ for springs, I scale them on my spring tester and w/ only (2) races worth they are 'typically' still good and within spec. Note...if you look here on 'Bob's', you will apparently realize that 'many' motors will still have Illegal springs in them after Only (2) races...
KOZ, I would agree with the advice offered by Weddle, with one exception .....
On customers motors, I have a standing rule that anytime the rod cap comes off, it gets a new rod ... maybe overkill, but in my opinion, cheap insurance considering the price of a rod (less than $10)
Now on my personal motor I would probably reuse the rod, BUT at minimum I would replace with new rod bolts.
Then as Weddle stated ... lap the valves, check/replace springs, new gaskets ... good to go !
Just the way stoney does it .... others may not agree .. but they should !!
jsstump#70
Member
I personally never ever reuse rings. That's just me. Whether or not rings "rotate" when running or return to the original spot has been debated by much bigger and better engine builders than I for 50+ years. If I personally tear an engine down after it has been run, I always rehone to get some cross hatch and install new rings. These "clone" rings are very forgiving and soft to easily seat so reusing them is being done by many, just not by me. A fresh hone and ring will always yield better compression than a reused ring and "slick" bore. As we all know "compression is the holy grail". Of course every "pound" of compression gained is very important on these low compression engines. Any time a "hone" makes its way into an engine, a very thorough cleaning and washing has got to be done. Just more time spent. JMO of course.
alvin l nunley
Site Supporter
seems like I remember reading somewhere that a fastener, Rod Bolt in this case, loses something like 38% of its strength the first time it's torque to spec. I don't remember the exact percentage after that, but the loss in strength is progressively less for each additional torqueing.
There are people in this world who get paid big money to figure all this stuff out. lol
Good point AL.....I wonder if Chinese 'space-craft' use the same bolts? ya think??
alvin l nunley
Site Supporter
were you around when that DC3 went down? As I remember it, it was determined that the reason that engine fell off was because a bolt failed. A Chinese bolt. The fastener industry went through quite an upheaval after that.
youngengines
Member
Just me, but I would put new rod bolts, hone the cylinder, put a new top ring, lap valves...and run it (if all the parts looked to be doing well).. JMO
We all seem to make this 'call' based on what We would do and I am 'assuming' that too be on our 'own' engines. However, what would 'We' be telling a 'customer' he should/must/can do under the same conditions? There are obviously many senario's involved. Case(s) at point....I have (2) customers (1 jr/1 sr) same conditions with minimal time on engines that got torn-down in tech for winning. Resolve: I suggested their options and both choose too hold onto their money and I re-assembled their motors (everything looked good 2go) for $30 and they repeated their performance a 3wks later....no tear-down that time. Moral of the story....'yes/maybe/sometimes' and (oh ya....common-sense)!
common sense, in some cases, isn't common... with some racers, it's sometimes a lack of that causes problems!! lol!!
i think that we drive our own boat and some of the decisions that we make are, shall we say, less than what we should have done? is that a polite way to say that sometimes we're the front of the horse and sometimes we're the rear? i know that i've been called a horse's patooty a few times!!!
i think that we drive our own boat and some of the decisions that we make are, shall we say, less than what we should have done? is that a polite way to say that sometimes we're the front of the horse and sometimes we're the rear? i know that i've been called a horse's patooty a few times!!!
ClausenRacing51
New member
I guess it comes from my 2 Cycle background.... I always figure if it needs rings it most likely needs a piston. I tend to see these clones with the ringland wore out long before the rings are. JMHO and what I have been seeing here in the midwest