Bests & Worsts Reviews from Amazon

Overview: This is an excellent model kit for the intermediate to advanced modeler that is interested in how an internal combustion engine works. The major mechanical components assembled into the engine block by the builder include the crankshaft, crank pulley, connecting rods, pistons, wrist pins, cam shafts, timing sprockets, timing belt, cooling fan, fan belt, rocker arms, valves, and valve springs. These are the solid parts of an engine that move around a lot and are the most interesting to watch. Ancillary components that are assembled by the builder but not as detailed are the water pump and throttle body. Not included in the model design are the radiator, oil pump, fuel rail, fuel injectors, alternator, and oil filter. These components are not necessary to understanding the combustion cycle of a gasoline engine, and there isn't anything interesting to be seen inside of them. The kit includes an ignition system composed of a battery (3 AA cells installed in the motor stand), two distributors, and eight LED spark plugs that glow red during the power stroke. Modern passenger car engines don't have distributors mechanically connected to the cam shafts, but it is easy to just think of them as coil packs fired by the timing sensors of the engine control module (ECM). The flywheel and torque converter (or clutch) are replaced with an electric gear motor that turns the crank shaft and thus all the mechanical components of the engine. The model is started by pressing a button on the motor stand which also contains a speaker that produces engine start/run sounds while the model is operating. When assembled the Haynes V8 engine model does an excellent job illustrating the concepts and core components still in use by virtually every gasoline engine in production today. The component colors chosen by Haynes are excellent and the finished model is very impressive and professional in appearance. Although it is possible for younger children to assemble the model with adult assistance, it is best to stick with the 14+ recommendation to ensure the best results due to the number of parts in the kit and the complexity of the assembly process. Recent Changes to the kit: 1. A number of kit builders have reported problems with the timing belt slipping off the camshaft or crankshaft sprockets. The engine block mold was changed to include two posts on each side of the crankshaft sprocket. These posts cause the timing belt to wrap more fully around the crankshaft sprocket and increases belt tension sufficiently to prevent slipping. 2. A number of kit builders have reported problems with the electric motor gear not mating correctly with the flywheel resulting in slipping once per rotation. This has been corrected in current kits with a motor gear set further out from the motor body. Recent Issues with the kit: When the kit is completed according to the directions, the mechanical timing of the pistons and valves is correct for the 1-5-3-7-4-8-2-6 firing order indicated in the assembly manual. However, the ignition timing of the LED spark plugs is NOT CORRECT and cannot be adjusted within the range of movement allowed by the distributors. To correct this problem, remove and re-install the distributors so that the distributor marked "1-4" is attached to the camshaft for cylinders 5-8 (rear left side), and the distributor marked "5-8" is attached to the camshaft for cylinders 1-4 (rear right side). Then adjust timing as instructed in assembly Step 27. This issue may also affect older versions of the kit. General Assembly Notes: Assembly does not require glue, lubricants, or paint. All plastic parts are molded in grey, blue-grey, black, chrome, or clear. Some parts are snap-fit while others are screwed together using metal self-taping screws. The screws are all the same size and the kit includes more than enough to complete the model in case some get lost during assembly (I had 17 left over). Starting the screws is easy thanks to the magnetic screwdriver included in the kit. However, driving the screws requires the strength of a mature hand. Young children will not be able to assemble the kit without adult assistance. Most parts are large, sturdy, and easy to handle. The smallest plastic parts in the kit are approximately 1/4" in diameter and there are only 8 of those. The smallest metal parts are the screws which appear to be #1-1/4 which is quite small and 105 of them are required to complete the kit (my kit included 122). The valves and valve spring parts are the most sensitive to stress and the manual recommends using care when installing them. I was able to assemble the entire kit without breaking anything by using only reasonable force, testing for a good fit before tightening, and working on a flat and well lit table surface. All parts are contained in plastic bags divided roughly in harmony with the assembly steps so that you only have 2-3 bags open at any one time. Some parts are loose and ready-to-assemble but most have to be cut away from a carrier frame before assembly. A sharp knife (not included) is required to easily remove parts from the carrier frame which is another reason this V8 kit is recommended for ages 14+. Most assemblies are designed with symmetrical parts that can be installed without concern for left/right orientation. Where that is not possible, the model design aids the builder with asymmetric shapes, screw patterns, and alignment pins to ensure parts can only be installed one way. The Assembly Manual: Haynes is a world-class Technical Manual company and their expertise really shows in the assembly manual for the V8 kit. It's printed in heavy gloss paper and provides excellent illustrations for each step. This is a manual you will want to keep after the model is finished. The Introduction does a good job of explaining the design choices made for the model so that the assembler knows why certain parts are built the way they are. I am very familiar with engines built for passenger cars and trucks but not very familiar with engines used for exotic performance cars. The design of the Haynes V8 is more closely aligned with the engine used in a Farrari than my Yukon and the introduction did a good job of explaining the differences. The "How an Engine Works" in the back of the manual is an easy to understand tutorial on the 4-Stroke combustion cycle and a brief overview of each engine system including Ignition, Fuel, Emission, Management, Lubrication, and Cooling. There's a glossary of common engine terms for those wondering what their auto technician meant when she said, "your head gasket is leaking which is why your compression is off and there's oil in your coolant". There are only two minor weaknesses in the manual: 1. In two places the manual uses the unfortunate shortcut paraphrased as, "Now that you have done everything for Part A according to this beautiful illustration, go ahead and do the same thing for Part B without an illustration". Unfortunately, Part B is significantly different from Part A and it would have been better to illustrate Part B in a separate assembly step to avoid confusion. 2. Occasionally the manual uses words to describe an assembly step when an illustration would have been better. For example, an instruction to assemble the upper and lower cylinder head is accompanied with a very good illustration of the upper and lower assemblies coming together. But then the instruction says, "Secure the head assembly with four screws" without showing where those screws should go. It can be determined where the screws should go by looking at the assembly, but it would have been helpful to illustrate it. Assembly Tips for best results: 1. A sharp knife is essential for easily removing parts from the carrier frame and trimming flash from the parts. I used an Xacto #2 handle and new #2 blade. 2. It is absolutely essential that all flash be removed from all rotating parts and the bearing surfaces of the engine block and upper/lower cylinder heads. The more time spent here, the better the model will be. 3. Use plastic sanding paper or an Xacto knife edge to smooth the plastic surfaces where flash has been trimmed. 4. Don't use lubricant. Lubricants take time to apply and make the model look messy, and their viscosity can increase the motor torque needed to rotate the crankshaft resulting in noisy and rough operation. The V8 model kit will not be operating under load or rotating at high speed or operating for long periods of time. The V8 model was designed with loose fitting moving parts that require minimal forces to operate. This makes the model easier to manufacture and much easier to assemble, but it also defeats any benefit a lubricant can provide. A better use of time is making sure that all flash has been trimmed and smoothed out so that sharp edges don't hang moving parts. 5. Check each rotating assembly after every step to make sure everything continues to move smoothly after new parts are added. 6. Use lint-free cloth and a can of dust spray to remove dust, fibers, hair, and plastic bits from rotating parts and the inside of clear plastic surfaces. 7. Double-check assembly instructions and test fit parts to make sure everything fits properly and slides/rotates smoothly. Don't be afraid to glue or trim something. Just make sure you know why the adjustment needs to be made and have verified that the adjustment will not interfere with later assembly steps. My Assembly Issues: 1. Special attention should be paid to mold lines on the crankshaft journals and flash on the outside edges of the connecting rod end caps. If not removed, these imperfections can cause the crankshaft to bind resulting in uneven engine rotation, popping noises, and occasional engine lockup. 2. Special attention should be paid to the engine block bearing surfaces after the crankshaft has been installed in assembly Step 5 to remove any bumps, flash, or mold lines that interfere with smooth rotation. 3. Check and double-check the assembly instructions to make sure the crankshaft and cylinder block are installed correctly in assembly Step 5 and Step 6. The new timing belt pins on the cylinder block are not shown in the assembly illustrations and it is easy to get the orientation confused. 4. Check that the narrow plates containing the valve guides in assembly Step 7 for both the A and B cylinder heads fits all the way down and flush against the exhaust channels. The clips on the right and left side of the cylinder head may not hold the plate down tightly which will cause the exhaust valves to hang when they are pushed down by the rocker arms. I used plastic model glue and hand pressure for 15 minutes to ensure the narrow plate stayed all the way down against the exhaust channels. 5. It is essential that all flash be removed from the intake and exhaust valves before they are installed or the assembled valves will neither look right or operate right. This is the most challenging part as the small valves require a steady hand with the Xacto knife. Yow! 6. When pressing the valve onto the valve stem, avoid compressing the valve spring completely against the cylinder head. This deforms the spring and reduces its strength. I used my thumb and index finger to push the valve and valve stem together while keeping the valve stem from being forced toward the cylinder head. 7. Check and double-check your work in assembly Step 7 through Step 14. The manual uses a few "and now do the same thing for the other side" shortcuts without illustrations that might be confusing. Watch closely for differences in the orientation of the rocker arms between cylinder head A and B. Check and double-check that the assembled camshafts are installed on the correct cylinder head. 8. If the ignition timing doesn't look right in assembly Step 27, swap the A and B distributors and try again (see Recent Issues above). Final Comments: The Haynes V8 kit is the best model gasoline engine available today in my opinion. It uses a modern design which is more representative of that found in a modern performance car. The Haynes 4 Cylinder (aka Smithsonian Motor Works) model is based on an obsolete design with a carburetor. The Revell Visible V8 is based on an obsolete design (carburetor and generator), does not demonstrate the electrical ignition system, and is hand-cranked (boring). The only comparable kit, the Testors V8 Hemi, has been discontinued. When completed, the Haynes V8 kit looks very professional, is technically current, reasonably accurate, and is closest to the V8 kits we always wanted to build when we were kids: Working mechanical parts and blinking lights.