Tech Q&A - April 2014

Kevin McClelland Feb 16, 2014 0 Comment(s)
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"FLO" Knows

Ok, by know you have all seen the Progressive Insurance commercials where you can get deep discounts by installing their "SnapShot" data logger into your OBD II diagnostic port and recording your driving habits for a 30-day period. They claim that they monitor how often you slam on the brakes, miles driven, and when you drive. They are looking for high-risk times that you drive like between midnight and 4 am. With this data they can assess the proper insurance rates. Along with the data they list above, they could also record vehicle speed, throttle opening, engine speed, etc. With this tool, the insurance companies could rule our lives and our enjoyable driving habits.

This brings me to a little story that happened this week, and the resulting work that I'm off to the garage to do. Coming home from work three days ago I noticed a small puddle of something under the rearend of Daniel's 2003 Z06 Corvette. When I got out of the car and laid down to check it out there were two puddles, one from the day before, and a fresh one from today. It appeared that it was gear oil coming from the differential. My heart dropped as I looked at the factory rearend attached to the back of the 6-speed manual.

Well, I rolled into the house and told Daniel that there was a puddle of oil under his rearend. After dinner we went out to check out what we could find. As we were all standing around after checking for the source, I asked him "Did you wheel hop the thing before you had the new tires put on the car, or after checking out the traction of the new tires?" The look on his face was priceless. The day before, I found the oil leak before he installed four new tires, as the original Goodyear F1's were dead. They were great, they would spin, leave no evidence, smoke, or noise to draw attention. The new tires are a type of very aggressive performance tire that really gives the car grip. I figured either he had burned the tires down before the new install, or the new grip shocked the differential and possibly caused the oil leak.

Kevin 2/2

The point I'm trying to make here is, you young hot rodders out there; if you're raised in a gearhead house, I doubt there is anything you can do with a car that we haven't already done! I would never put a tire on my big-block Chevelle until I could see the air through the tire. I couldn't afford killer tires so I would put the best front tires I could afford for handling, and Caldwell re-treads on the rear. I couldn't keep a set on the rear for longer than six months. That would bring me to a citation for "Breaking Traction," but that's another story.

Well, I'm glad that I'm finished with this month's edit so I can put some real tools in my hands and help Daniel fix his car. Hopefully, it's something simple, and not what I'm reading online about the left side oil leak, which is common with these diff's. The warranty time to fix this issue is only 2.2 hours. What that means is that you have to about double that for an at home garage repair. Oh, bother! Wish me luck.

Ford on the Mind!

Q. I wanted to make a correction to Kevin McClelland's article in which he was talking about the 2-6-6-6 Allegheny Steam locomotive. His statement of pulling fully loaded coal cars at 60 mph is false. It could in fact pull passenger cars that fast, but was only ran at 18 mph pulling loaded coal cars through the mountains. The museum web site states this fact about its top speed. I know it's not car facts but I wanted to ensure the true facts were printed. Thanks!

Chad Kollars
Council Bluffs, IA

A. Chad, we're with you and this is why we're printing your correction. Yes, we always want to print the facts, as that is the purpose of this exercise. Now, for an excuse! How about a Chevy guy that has lived, eaten, and breathed General Motors all his life roaming the Henry Ford Museum. What do you expect? I'm surprised that I haven't started painting engines Ford Blue, and thanks again for the correction!


Rare as Hen's Teeth

Q. I am a long time subscriber to your excellent magazine, and I have a question. I have a 350 engine in my hot rod and I found that I have a cracked head, casting number 3973487X. These castings are hard to find, and expensive, and was wondering what other more available/less costly casting that will work next to the 487X so I don't have to change both heads as I am on a tight budget. Thanks for any help.

Lou Lopardi
Tolland, CT

A. The 3973487X heads were early castings that were produced from 1968-73. These were some of the first castings with the accessory boltholes in the end faces of the cylinder heads. They were especially sought for their slightly larger intake runners than the standard cores that casted the 487 cylinder heads. Both of these casting numbers were either equipped with 1.94/1.50 and 2.02/1.60 inch valve packages. They are within 0.1cc difference in combustion chamber volume coming in at 75.4cc. The standard 3973487 casting was used from 1968 through 1979.

If the "X" heads actually had slightly larger intake runners you wouldn't know it from the engines they were originally installed on. They were used on 350 cid displacement engines producing anemic power levels of 165, 175, 200, and 255 horsepower levels. I believe that all of these engine combinations came with the Rochester 2-barrel carburetor. As for the standard 487 castings, they were also used only on the 350 displacement engines, but with much higher power levels. They were also used on the pedestrian engine listed above, but were also on a 330 hp 350-cid small-block.

The bottom line is the 3973487 casting will work just fine next to your "X" head. Make sure that you run matching valve sizes and the very slight combustion chamber difference won't make a hill of beans. Check around your local area to see if you can pick up one of these castings. If you can't find one, give Cylinder Head Exchange a call in So. Cal. My brother-in-law Tony Knight has been there for over 30 years and their inventory of current model, and vintage cylinder heads will blow your mind. I'm sure that he could scrounge you up a 487 casting and prep it to whatever configuration you need.





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