THE SLEEPING BEAST - A STROKER
311 Stroker Engine Tech Section
To stroke or not to stock-that is the question. There are two pretty basic options and a third one I have heard about but never seen for the lower end. Either of the first two options requires a later 5 main R16 block. I believe engines 40001 and above were 5 main.
Next you have to make a choice as to what crank, rods, and pistons to use. I used the H20 crank and pistons which is a direct drop-in for the R16 with no modifications. The H20 pistons are dished which will reduce your compression ratio with an uncut head. They are perfect for an aluminum head that has been cut too much. The part number for the H20 crank is the same one NISMO uses as a stroker crank. It is 12200-E0700. I priced an H20 crank new at $516.00 which is more than a bit pricy. Several have picked the NISMO stroker crank up for around $325.00. Shop around. The 1600 fly wheel and crank pulley bolt right up. Some have reportedly used the U20 dampened front pulley. I really find no need to do this.
The U20 crank with the U20 flat top pistons is your other choice. The problem with the U20 crank is that you must have the front end of it machined. What do I mean by machined? You have to have exactly 1" removed, the crank pulley hole re-bored and tapped and a key-way put back in. I did not go that route so I have no idea what the costs may be. A lot depends on where you are located. Not cutting the crank will cause you all kinds of grief as the water pump and alternator pulleys will not line up with out mickey mousing something together. Another way you could go about this is to take the machine shop a 1600 crank and have them match the U20 crank up to it exactly.
The third option for the lower end would be to use a G-15(1500) crank in the R16 3 main block. I am told the displacement would be right around 1900- but will not be quoted on that one.
I am biased but I like the H20 modification on my car. My compression ratio is right around 9.2 to 1. Not too high with plenty of power. Here is a list of H20 parts that can be used in your R16. There is alot of skepticisim concerning the use of H20 parts but what many fail to realize is that the H20 is used in cars in many overseas markets. I have driven the snot out of mine and it is holding up very well.
The cam I used is an ISKY DR66 with an L/C of 109. Here is a link to Joe of American Cam Grinding who can make you up a stroker cam. It is not ISKY but Joe is very familiar with our roadsters and stroking. Click here to check it out. Stock timing components as well as H20 bolt right up i.e. sprockets, tensioner and chain. I used a 2 liter oil pump but there is currently a debate on the 311s.org forum concerning the differences. More to come on this as it evolves. If you do use the U20 oil pump you will have to replace one of the bolts with a stud as there is not enough room for the bolt. You will see what I mean if you do it.
Carburation choices vary as well. I used the 2 liter carburators, velocity stacks, a hogged out R16 intake and a ITG air filter. You can read about my intake and linkage modifications by clicking here. It took me a bit to get the carbs dialed in but I am happy with the set-up. I ended up replacing the stock 2 liter needles N17s with some RB needles from Joe Curto. Either the RBs or RHs from Joe are a good choice. Joe has a web site you can vist by clicking here! Plenty of low end pickup and top end speed with 29 MPG on the freeway and 22 MPG in the City. Your other options include but are not limited to Mikunis/Solexes, Webers or 240Z SUs. My brother Dave used the smaller R16 carbs with great success using some British SU needles (M7) compliments of Joe Curto. I am sure there are others but that is all I can think of at the moment.
The head work is not as key of a component in the stroker as I first thought. Several have used the aluminum R head with stock valves and still have a screaming motor like my brother Dave. I prefer the cast iron head over the aluminum for its durability and ease of machining. I had my head ported polished and refitted with "small block" Chevy intake and exhaust valves. You might say they are over sized and quite possibly overkill.
Stroker motors with a cast iron head tend to run a we bit hotter than a stock R16 with an aluminum head. At least that has been my experience. Not overheating hot but around 195 to 200 degrees. It must be the nature of the beast. I had a custom aluminum radiator fabricated by Griffin complete with an electric cooling fan. This is all thermostatically controlled by water temprature for added protection. I was able to remove the stock fan from the water pump picking up an additonal HP or two. Your other option is to use a 2 liter radiator for increased cooling capacity.
People usually do not take a second look at my motor because it looks like a stock R16 on the outside except for the bigger SUs - But it sure does not run like a 1600. I believe there might be one or two running the racing circuit as 1600's but I could be wrong. Any one heard of the term "Sleeper"?
Last but not least, I am sold on using Gary Boone's EI Dizzy. I have purchased four of Gary's units including one for my Z car. The performance gains are quite noticeable and the installation is a breeze. Why stick with points when you can go true Nissan EI? The points we get today are very low quality and do not seem to last long in my opinion. If you are interested you can read about Gary's EI dizzy by clicking here?!
Going the stroker route is not for everyone but it does provide an attractive alternative to a U20 rebuild. Parts are readily available and depending on where you get the work done or how much you do yourself cost savings will vary. Any way, good luck at what ever choice you make.
Here is a site that sells after market H20 components. They are in Kentucky, USA. These people do not sell cranks. Component prices only! I have purchased parts from these guys and the price is right and I received the parts right away. Just tell 'em you are working on your fork lift.
Click here to visit their site!
Another option is to locate the nearest Nissan forklift dealership and purchase parts from them.