More hot rod building distractions!!!
Having a daily driver for car and two custom cars can be a problem. As you know this website is primarily devoted to the building of my 1929 Ford Roadster Hot Rod using C4 Corvette suspension components. I also have a custom 1987 Corvette convertible. If all we could do is work on one thing that would be great. There is the day job, things to do around the house, and your kids and family always need some help with something. The distraction this time is the 1987 Corvette convertible.
The engine for my 1987 Corvette convertible needed to be re-built last year for a number of reasons. It all started just as my vacation was starting in the beginning of July 2009. I was coming home from the College I work as and about 40km from home the engine started missing. I thought this would not be much. Usually, with this type of problem, it could be a bad spark plug, a problem with the distributor cap or rotor, or even a bad spark plug wire. Sometimes even a fuel problem. After a few days checking all of these things over, I was not making any progress to locating the problem causing this engine miss. It was at that point I thought a compression test was in order. Now the engine was just rebuilt without too many miles on it. I started the doing the compression test on the cylinders on the drivers side of the engine. All of these measured over 200 psi and within a few psi of each other. So far so good!! Over on the passenger side, I started with number two cylinder and found it had no compression at all. This was not good. Continuing with the rest of the cylinders on the passenger side of the engine produce similar results as the drivers side of the engine. I thought the worst, a cracked block, head, or even a blown piston. OH NO!!!!!! To make sure, I thought it would be a good idea to narrow the problem down a bit more. Not having a cylinder leak down tester, I decided to quickly make one. This is the story of my life. If I do not have something, especially a tool, why not make it and save a few valuable dollars. This will be another video soon. Anyways, I brought number two cylinder up to top dead center and pressurized the cylinder. The first time I did it, air was blowing through the intake and into the throttle body. This meant a bad intake valve. Making sure, I did it a second time. This time air was blowing into the crankcase. This puzzled me. After a few more attempts at this, half of the time the air would blow through the intake and the rest of the time through the crank. At this point I realized this was a problem that I did not want to deal with and decided to pull the engine.
With the engine out, I felt that a shop that rebuilds engines for a living should look at the engine. I decided on a reputable machine shop in London Ontario. It was Atchison Machine Service Inc. at 132 Clarke Road South, London, Ontario. They have a new website at http://www.atchisonmachine.com/ . Part of my decision to use this shop is that they build racing engines and should know what they are doing. In 2003 and 2004 Atchison Racing was the IHRA world champions in the top alcohol funny car class. This machine shop started in 1964 as a result to an early start in local racing in the London area. Visit their website for more information on this team at http://www.atchisonracing.com/ .
A few days after dropping the engine off at Atchison Machine Services, Dennis gave me a call with the news. Number two valve intake spring was broken, and the head gasket was blown by number two cylinder. Now this explained my odd engine cylinder leak down test. I think what was happening the air pressure would occasionally push the intake valve up and seal in the head causing air to blow through the blown head gasket. If the valve didn’t seal, then the air blew through the intake. Oh well. I gave Dennis the okay to do what ever was required because pulling the engine out of the 1987 Corvette was no picnic. At the time I was having back problems and so was Dennis. I suggested that they could take their time since there was no hurry to get the engine back.
A few more days passed and Dennis gave me another call. Dennis found that most of the valves were unevenly worn, the majority of the valve guides worn out, and most of the valve guide seals smashed down. Remember this was a freshly rebuilt engine with next to no miles on it. The heads and block needed to be milled and the block line bored. This was a little odd for a rebuilt engine. Again I suggested to Dennis to do what ever was required and just make it right.
Several more weeks passed and yet another call from Dennis. As Dennis was re-assembling the engine, he noticed the 1.6 ratio roller rockers. With the 500 lift cam in the engine, Dennis did a few calculations. Dennis discovered that the rockers were wrong for the engine. They should have been 1.5 ratio rockers. Now this explained the damage to the valves, valve guides, valve guided seals, and the probable cause of number intake valve spring breaking. He also mentioned that the tolerances were so close, it was a wonder that the valves didn’t go through the pistons. A one point I considered to put my car on the dyno at the College I work at and find out how much horsepower the engine was creating. It was a good thing I didn’t, or the engine would have self destructed. This is why you should leave the engine re-building to the professionals. They know what they are doing.
I finally got the engine back early in September. With summer vacation over and back to work, shop time did not exist. Work at the College was time consuming, my kids needed a bit of help, and in general family life took precedence. Now that I am back into summer vacation, I can get back to the Corvette, and then to the 1929 Ford Roadster hot rod.
Currently, I am just getting back to installing the engine back into my 1987 Corvette convertible. Everything on the engine and engine components was cleaned and painted. I even polished the entire TPI injection system parts, valve covers, alternator bracket, and a few other parts. A fresh coat of low gloss black was used in the engine compartment. This should look pretty nice when completed.
My next post will be on making an engine pre-oiler for the small block Chevy or SBC engine. With the engine sitting for almost a year, it will be important to prime the engine or pre-oil it before firing it up. It would be a shame to mess this up now and so close to having the Corvette running again.