Lesson for the younger guy's

It's probably been said a thousand times already,,,,but just in case it's been forgotten,,,here's something i was teaching my son about buying that beautifull old car from an equaly old person,,.
After finding that special car that was driven by an old lady,,or old man, just to go to the store and back,,,very little miles,,,no dents,,faded paint, the most common mistake made by some of the younger guy's ( I speak from long memory ) is taking that nice old car and gunning it before ridge reaming the cylinders,,,ending up with a motor that smokes and burns oil,!
An engine gets conditioned to the driving habits of it's long time owner.
Let's say the origional owner drove the car in the low RPM range,,,say,,,2800 RPM,*JUST AN EXAMPLE*,,,,,and now you own this rare prize,,,,the first thing your gonna want to do is give it some gas and see what the old girl will do,,,,,,I mean,,,It's a Hemi or big block right??
So off you go and take the RPM's up past the 2800 mark,and open that dusty old four barrell,,and you are impressed!!!
Well,,,,,now youv'e gone and done it,,,the higher RPM's have increased the piston travell in the cylinders,,,and the rings have hit the ridge of built up metal at the top of the cylinder travell, and cracked as a result,,,,,now it's smoking, and using oil,,,and your cursing that old fart who sold you this bill of goods.
He said it didn't use any oil,,,and the compression was really good,,and when you first took it for a test drive with him in the car,,you could tell it had TONS of torque,,,and just wanted to fly.
What you are forgetting is that the pistons in an engine will build up ridges of metal at the top of their stroke,,,and the RPM range the origional owner would drive at,, have determined where the ridges would be,,,,,after you have revved it past that point,,,whatever it may be,,,,the piston's have exceeded the normal stroke range,,and the rings have hit that built up ridge,,and cracked.
So now you have cracked rings and most likely scored the cylinders, leaving you with a big repair bill.
Most of us older guy's have been there,,,,,,and when it's your first car,,it really hurts.
Like i told my son,,,,,get yourself a gasket set,,,and a ridge reamer,,,pull the cylinder heads off,,,and use the ridge reamer to remove that built up ridge at the top of the bore.
Your total extra cost should be around $150,,,,and you can now ( in most cases) take the engine higher up in the RPM range,,,,End result for a little forethought,,,,,*HAPPINESS*
You probably want to upgrade the heads and intake anyway.


:3dSMILE:

Know what you mean. My Dad took me out at 15 to buy a 58 chevy impala(always liked them) and we looked at one at a dealer. I drove it and the motor was shot(348), front end was shot(needed ball joints and tie rods) tranny wouldn't shift right(3 speed on the colume) but I bought it anyways against my Dads better judgement. Learned a big lesson the day as it sat because I had no money to put into it and finally when I did the engiine had a cracked block,front end was totaled,tranny was past repair and I was out $300.00 Managed to sell it for $100.00

Yeah,,,my first car was to be a 1958 olds 2dr hard top,,,i was a trusting sould back then ( 16yrs old ) the guy at the gas station let me make payments on it while he kept it on his lot,,,i dealt with the guy on a hand shake,,,and just when i was making my final payment,,,some six months later,,,,,i found that he had sold the car to someone else,,,,,,i had no reciepts,,,my dad was away commercial fishing for months on end,,,my mother raised hell with the guy,,,but to no avail,,,,lost the car,,,lost my money,i was devastated.
I backed myself up with paper thereafter,,,,,once burned,,,twice shy.

There are alot of guys out there that will take advantage of a young kid and we were two of them!:(

Every thing was ok when my dad came home from fishing,,,he bought me a 1958 GMC pickup,,,,,i was a happy kid.

Ya I guess I would be happy myself if my Dad had done the same, but I had to buy the next one myself(41 ford pickup) and I had alot of fun with that.

Thunderbucket- boy is that right. You don't even have to be leadfooting it . Just having a new owner using a used car differently and bring out all sorts of stuff the old owner never had a problem with. If you drive freeway and the old owner never did. If you do lots of night driving and the old owner never did. If you start it often in your daily routine and the old owner never did. ...Well you know....

Good lesson Thunderbucket!


~ Vegas ~

how the hell do u increase piston travel, at rpm they all travel the same distance, if anything the carb was prob bad giving too much air and causing the motor to knock, or those rings where rusty.

Ya how is it possible for the stroke to change regardless of rpm and it being babied for years? I can't envision any way for the piston to travel more or less at different RPM unless something is wrong.

I asked my teacher about that. Here is the answer I got. The con rods and all will flex or whatever and cause the metal to expand more under more heat, etc and hit that ridge. If you think about it it's true.

Difference in RPM will cause a difference in crank flex,,,also,,,every moving part of an engine will change tolerance with either RPM or Heat,,,,,I know it dont seem possible when you first look at it,,but metal,,,any metal will stretch and deform with enough reciprocal, or centrifical force.
We are only talking mere thousands of an inch here,,,,,piston travell and ring run in,,will cause ridges to build up at the limmit of the TDC point of the cylinder,,,when the RPM is increased all of a sudden after years of consistent low RPM,,,those thousands of an inch will give you lots of greif.

Which of course is why it's healthy for your motor to be taken for a good RPM run once in a while,,,to prevent the setting in of such build ups.

It's the same with small engines, if you run an engine with a governer which all small engines have except dirt bikes and racing go karts but they have rev limiters nowdays, if you pull the governer off say a 6 horse ) OHV Techumsea powersport ( Common go kart engine ), that has been in use for a number of years, and get it past the rpm it had run at b4, it is going to snap the ring, I know, I had to fix 1 that did that, getting the pushrods back correctly was hard though.

Thats why i said earlier,,,a ridge reamer is your best friend.