Tip of the Month
At the risk of causing a firestorm here at Resto Tech, a recent attempt to help a friend solve a cooling problem on his ’36 Ford does draw a parallel for all our Chevy owners. It’s a Ford, but it does have a Chevy drivetrain. What does that tell you? Let me explain. Doug just got his ’36 Ford out of a local shop after a two-year build. All systems were go, except for a pesky overheating problem, especially with the A/C on. We quickly determined the mechanical fan was too close to the radiator. No choice there since the engine was mounted so far forward a shroud wasn’t an option. It had a conventional brass radiator. Options included parking the car, putting in a thinner aluminum radiator with huge electric fans, or moving the drivetrain back into the firewall, thus making room for a larger mechanical fan. It was evident that like any Chevy, the advantage of a fan shroud can’t be ignored. A shroud that covers the entire radiator forces the air to be drawn through the entire surface of the radiator, enhancing cooling by a ton. Also, puller fans mounted behind the radiator on the engine side work 20- to 30-percent better than front-mounted fans. No matter what make or model, the proper radiator with proper airflow is the key to keeping any classic cool. Take a look at the accompanying picture and its plain to see this example gives the incoming cooling air no choice but to travel through the entire radiator surface. Although I’m a big fan (pun) of large mechanical clutch fans and their ability to pull huge amounts of air through the radiator, in this case that option just isn’t possible. This puller set-up was done right and is problem free.
Let It Bleed, Reprise
I was just reading your repair section questions in May’s Resto Tech column. You had a reader ask about a new disc brake system not working on his Impala. I have installed a dozen or so of these disc kits that come with new master cylinders and boosters. Your answer was real close, but not quite totally right. Almost none of the kits come with a new brake rod that goes between the pedal and the piston, and if you reuse the one from the car, it is not long enough to bleed off. What I have done is go to Chevy and buy the longest rod they have and just start grinding until you reach the proper length. If not done right, you may hit the brakes and send yourself through the windshield, or just the opposite and not have any brakes. As you know, they make a dozen different lengths of rods.
Thanks for the letter, Fred. We always welcome feedback from our readers. Two heads are always better than one. Although most disc brake conversions are model specific and should have the same depth master cylinder piston, you and I know that’s not always true. Measuring the depth of the old cylinder and the new kit is always a good idea. They even make a tool to measure the depth and length of the rod. Grinding a rod to fit is probably the most economical way to get the result you want, but if you’re in the business of installing brake conversions, it might pay to get yourself a depth measuring tool and a few adjustable push rods. Both can be had at MP Brakes at 877-841-3470 or www.mpbrakes.com
I have a ’67 Impala SS. The casting numbers on the back of the block are CM8970010, and the engine suffix code is V0427CKK. What can you tell me about the engine? What did the engine come out of? Thank you in advance for your time.
Let’s take the suffix code first, Trisha, and see what you have and verify it matches your block casting number:
V = Engine built at Flint engine plant
04=Built in April (year not included in this code)
27=Built the 27th day of April
C=Chevrolet Division of GM
KK=’72 Nova, 175 hp, 350 ci, mated to either a three-speed or four-speed manual trans
So far so good until we get to the casting number you provided. The first number is probably 3 instead of an 8. Common mistake reading casting numbers, so if the casting number is really 3970010, it would have come from a ’69-’72 vehicle and could be from a car or truck with a two- or four-bolt main. Since the suffix code indicates a ’72 Nova, it all makes sense. Hope this helps. Thanks for the letter.
Got a restoration question that’s been puzzling you? Send it to:
[ m ] Super Chevy, Resto Tech, 9036 Brittany Way, Tampa, FL 33619.
[ e ] email@example.com
[ f ] 813/675-3559