Mustang MonthlyHow To Tech Qa
1965 Ford Mustang Hi-Po Fastback & 1968 Ford Mustang - Beyond The Basics
Mustang Tech Questions
Single To DualI'm interested in converting my "single" reservoir hydraulic brakes to the "dual" reservoir system, but I want to retain drums throughout.
Your "How To:" sections are great, and have helped me immeasurably with several home shop rebuilds (power steering, windows, etc.)
Can you tell me which Mustang Monthly issue covers the brake conversion? I have many back issues to go through-eight years or so. I'd appreciate your help and understanding.Stirling ParkersonLaurel, MS
We appreciate the kind words and are glad we've been of help in the past. As time goes on, more and more items become available for our old Mustangs as the market demand and manufacturing techniques allow for development. This is quite evident when it pertains to brakes, as many people prefer to update their Mustang brake systems to modern standards.
I'd suggest you contact Master Power Brakes at (704) 664-8866, as they offer complete kits to convert early style brakes to their more modern counterparts. I prefer to use kits whenever possible to eliminate any last-minute surprises and the aggravation associated with finding an obscure piece of hardware. A dual master cylinder is easily installed on an early Mustang as the bolt pattern on the firewall is the same for both single and dual master cylinders. Pushrod lengths will vary depending on the brand of master cylinder used. The plumbing must be changed so the rear brake circuit is separate from the front brake circuit. The factory incorporated a pressure differential block that contained a switch to illuminate a dashboard warning light should a brake failure occur. Utilization of this block will create the separate plumbing necessary.
If you don't care to have the warning lamp and aren't concerned with a bit of fabrication, you can easily install a stock '67 Mustang master cylinder. The stock pushrod can be modified to fit the dual master, and the rear brake system can be connected directly to the dual master cylinder with a length of 31/416-inch brake tubing and a brass union. The port that would remain open in the stock fitting on the engine bay apron can simply be plugged.
Hi-Po AheadI hope you can provide me with some clear advice. I have a '65 Hi-Po fastback, a true "K." My ground-up restoration of this beautiful Rangoon Red beast started over a decade ago (I originally bought the car from my oldest brother for $300 in 1978. I think he's still pissed for ever selling me the car!). This summer I plan to finally assemble enough of it to drive around the block and I don't want to make a mistake now.
My question focuses on the heads, in particular the pushrods and rockers. After reading my manuals and periodicals then listening to several Mustangers, machine shop guys, and my brother, I replaced the rocker-arm studs during the reconditioning of the heads and installed guide plates for use with a set of hardened pushrods. I planned to install a set of Crane aluminum roller rockers.
Recently, I heard and then read some information which conflicts with my plan. Can I (or should I) install hardened pushrods, guide plates and roller rockers on a set of HP original heads? Will the Crane rocker assembly need additional machine shop work for proper alignment? (Translation: Will this cost me another trip to the machine shop?). Or should I go with stock pushrods and steel rocker arms and avoid the hassle?
The machinist who performed the work on the heads told me I need a set of rollers with a 1.6 ratio for 31/48-inch studs. If it is possible to install roller rockers could you suggest a make and model best suited for my engine? And finally, I am aware that the installation of roller rockers means I'll have to purchase valve covers with extra clearance height.Wesley EllenwoodSaint Paul, MN
Your engine should have HiPo heads that are factory equipped with close tolerance slots in the head to guide the pushrods and maintain rocker arm alignment. These close tolerance heads do require hardened pushrods as they contact the slot continuously during operation. Guide plates are not necessary as the narrow slot does essentially the same job. Your machinist is correct in that a 1.6 ratio roller rocker for 31/48-inch studs will fit, however, they simply bolt in using stock hardened pushrods without guide plates.
The confusion stems from the fact that Ford stopped utilizing the narrow slot design in mid 1966 and switched to a "loose fit" hole that required "rail" style rocker arms. The loose fit hole did not support the pushrod and relied on U-shaped rocker-arm tips that drop over the valve stem to maintain pushrod/rocker arm alignment. This design does not allow for a roller-rocker arm unless guide plates are installed to hold the pushrod aligned. A copy of Ford's Motorsport Performance equipment catalog illustrates this quite clearly and is available from your parts vendor or Ford at (586) 468-1356.
I question your need for roller-rocker arms, as the stock HiPo setup is quite trouble free and can handle any camshaft style, both mechanical and hydraulic. California-area vintage racers are limited to stock rockers by the rules and are running to higher rpm than a normal street driven vehicle will ever obtain.
SpeedySome time ago, I brought my '68 Mustang to a speedometer repair shop as my mileage indicator and speedometer did not work. The shop said I needed a new drive gear in the transmission. I then brought the car to the transmission shop where they installed a new drive gear and a new driven gear. However, they could not locate the seven-tooth gear I needed so instead installed an eight-tooth gear. When I got the car back, the speedometer still did not work but the mileage indicator was going backward. I then took the car back to the speedometer shop and they checked everything out and said that the drive gear was installed backward and that was why the speedometer did not work.
I then went back to the transmission shop with my invoice from the speedometer shop and told them that the drive gear was installed backward. The transmission shop says that it is impossible to install the drive gear backward, as there is a slot on the gear so it can only be installed one way.
Please let me know how I can get this fixed before I get a speeding ticket!Douglas SvenkerudWest Chester, OH
Unfortunately, the transmission shop has installed a drive gear for a unit that has the speedometer cable entrance on the opposite side of the transmission. The angle of the teeth on the drive gear differs depending upon which side of the output shaft the driven gear is. If the incorrectly angled gear is installed, the effect is to rotate the speedo cable backward. Generally, automatic transmissions have the cable entering from the driver side whereas four-speed units enter from the passenger side.
You will have to locate the correct parts from a good parts vendor as the local shops will have difficulty from their suppliers. Most vendors who specialize in engine/transmission conversions are quite familiar with this situation and will have the gears you need. Don't forget to obtain the correct driven gear, as the angle of the driven gears are also opposite each other and must correspond with the drive gear.
No Pressure SixI have a '66 Mustang with a six-cylinder 200 engine, automatic transmission that I am working to make a daily driver. I drove it for a couple of years until I noticed rust appearing in the floor pans and over one quarter panel. It has been in the garage for about a year. When I parked it, the oil pressure was fine and I start and run it for 5 to 10 minutes every week. Recently, I noticed the oil pressure was 0, the gauge did not move. I flushed out the oil system using Gunk Flush and replaced the oil-sending unit. Now the gauge moves, but just barely into the safe range. Any suggestions about ways to check the oil gauge or wiring from the sending unit? Is there a way to check the oil pump without pulling the pan?
I read Mustang Monthly and your article concerning quarter-panel replacement was right on target. I am using the information to replace my right quarter panel. Thanks for your help.Donnie NorwoodOdessa, TX
Such low pressure is indeed a concern and should be checked before using the vehicle. I'd suggest you substitute a mechanical oil pressure gauge for the stock electrical gauge in order to read the pressure directly. This will tell you if the problem is with gauge or actually low oil pressure in the engine.
I'd suggest you purchase an inexpensive oil-pressure gauge at your local parts store. I found one for under $15 and use it just for testing purposes. Remove the stock sending unit from the engine and temporarily install the mechanical gauge under the hood, using the fittings included with the new gauge. Run the engine and observe the oil pressure. Hot oil pressure of at least 10 pounds at idle and 25-30 pounds at approximately 2,000 rpm is enough for an everyday street-driven vehicle.
If your pressure is below the accepted level then I'd suggest you consider an engine rebuild. Low oil pressure is usually a product of bearing wear and rarely the oil pump itself. Sometimes when an engine sits for long periods, acids in the oil attack engine bearings, so it's important to keep fresh oil in the engine during storage.