Engine parts

[thebig450es]

This winter I think its time for a rebuild on the ol 400, I would like to make it 416/ 11:1, and what manufacture do you recommend? And Gasket kit? I would like it to have true compression and reliable. I’m planning on installing a stage two cam at the same time. And Gt thunder head studs. im working on cooling issues now before the rebuild. Thanks

[aDviSol2y]

Originally posted by thebig450es
im working on cooling issues now before the rebuild. Thanks

Is your bike getting Hot? If so, you should not use the sparks key with the 416. Sparks recomends not to use the key on any bore kits, due to heat issues. Just an FYI. As for what kit to buy, I swear by wiseco, but there are other very good quality kits out there.

[thebig450es]

I don't have heating issues currently, but im planning on adding air scoops,and a spal fan before i get into the engine and hopefully i don't need to add a second oil cooler. What are good quality parts for the engine?

[aDviSol2y]

Like I said I prefer Wiseco, and I can't remember what gasket kit I used, it was years ago. But my rule of thumb is you get what you pay for. If the parts are cheap in price, they are proabably cheap in quality.

[thebig450es]

Is JE or anyothers better quailty?

[aDviSol2y]

Originally posted by thebig450es
Is JE or anyothers better quailty?

I have heard some good things about JE but I have never used them before. I have had my Wiseco in since '02, reved the $#!^ out of it on many occasions and its still running as strong as when I put it in. Does not smoke, does not burn excess oil. I am very happy with the quality.

[matt14c]

In my opinion JE makes a better piston for the fourstrokes. Wiseco is king in two strokes. But you couldnt go wrong with either. Cometic is the gakets you will want. There are a couple other piston companies but as stated previously you get what you pay for. You will want to replace your timing chain and tensioner also if your going this far. Then you will need an side cover gasket also. I have heard mixed reviews about using the sparks key with the 416. To be safe someone is making 3 degree keys instead.

[bbender85]

use a cometic gasket kit. when i did my top end last year i found a wiseco piston with namura gasket set kit; the namura base gasket and valve cover gasket are the cheap style, whereas the cometic kit i replaced it with this summer has the nice steel ones like the head gasket. my namura base gasket was leaking, and i blew the head gasket at 11:1 with 110/93 mix and good jetting.

[F-16Guy]

Wiseco, JE, Ross. All good names and reliable. My Wiseco has been running strong for years. I like either OEM XR gaskets if the bore is small enough (85-87mm) or Cometic with the MLS head gasket.

Something to ponder for both cooling and the build:

If you go with a FST style cooler (search Perma-Cool p/n 1008), you can eliminate the base gasket and use a sealant like Yamabond. The FST cooler re-routes the oil away from the passage where the cylinder and case meet, so you can use the Yamabond without worrying about blocking the original passage and causing oil starvation issues. By doing this, you'll solve a common problem: You'll effectively raise the deck height, which is too low with any piston that has an oem writpin location (which is most of them). By effectively raising the piston up in the bore at TDC by moving the cylinder down, the squish band (gap) around the top edge of the piston and the corresponding area on the head will be smaller. As the piston nears TDC during the compression stroke, the air/fuel mixture lingering around the outside edges of the bore will be violently forced to the middle, which agitates and concentrates the mixture for better, more powerful burning. This, along with cooled oil being dumped directly into the valvetrain, with make the engine run much cooler and allow you to run lower octane fuel more safely. I run 91 octane in my 400ex all day with no pinging or knocking.

[thebig450es]

Id like to do the OEM XR gasket to get the compression closer to 11:1. Also the FST style cooler, so keep the head cooler.

What would be a complete parts list

Wiseco 416/11:1
XR top end gasket kit
450r timing chain/ tensioner
GT thunder Head studs

Anything else to order , id like to do it right the first time?
Thanks

[F-16Guy]

Who's going to install the studs? Make sure it's done to GT Thunder's specs listed on their site with a good quality roll form tap.

If you're going to skip the cooler, my only other suggestions would be a HotCams Stage 1 cam, some assembly lube, a cheap ring compressor from your local parts store, and a decent torque wrench in an pounds/inch scale.

If you do the cooler, you may want to get some help on the install. There isn't much margin for error on the install, so you don't want to mess it up. You'll also need a right side (clutch) cover gasket when installing the cooler.

[thebig450es]

I was planning on having a shop install the head studs, i'd like to do most of it myself and the cooler, I was planning on a stage 2 cam

[F-16Guy]

Either cam is a great improvement over stock.
You can buy the cooler kit from Jegs.com for about $72 (Perma-Cool p/n 1008).

The cooler is a little tricky, but it can be done if you're decent with hand tools and a drill. My advice would be to buy a tap and plan to ruin it. Start with the rocker cover first, since it's a straight forward drill and tap job. Next, when doing the clutch cover, carefully drill the hole into the top of the passage. Then, when tapping, run the tap down into the hole until it hits the bottom of the passage. Now grind a little bit off the end of the tap and fix any burrs with a file. Run that down a little more and then check to see if the fitting will thread into the cover enough to fully engage the threads. Repeat tapping and shortening the tap until the threads are correct. The idea is for the bottom of the fitting to just barely protrude into the oil passage as it tightens up. Not far enough, and it will leak; too far, and it will sit at the bottom of the passage and block oil flow. Unfortunately, the tap will be too long to tap the threads to the correct size without either going through the bottom of the passage (you don't want that), or shortening the tap as you go. It's not as bad as it sounds, especially if you have a bench grinder or something to grind the tap down with.

[aDviSol2y]

F-16Guy, Can you come install the cooler for me? LOL! I have been thinking about doing this but am really nervous about drilling into my motor. All that I have read about the install say that the instructions are very lacking, but it is not as hard as it looks. I just don't know if it is worth the risk of fing up and destroying my motor. I will probably just put a secondary cooler on and a spal fan on. I know this is not as effective because the oil still has to pass through the cumbustion chamber to get to the head, but I think it will be enough. I have been running on stock cooling for years but I know when I have to let my bike cool, but sometimes i don't want to let it cool when it needs to. What do you think I should do? You seem to know your $#!^.

[thebig450es]

Thats great help F-16Guy, has anyone made detailed instructions with pics yet, ive been searching to no advail. Id like to do the perma cool and the spal fan before the engine work is done. Thanks

[F-16Guy]

These were posted in another cooler thread and look to be the best instructions out there:

http://webpages.charter.net/tandrus4700/400exCoolerMod.pdf
http://atv.off-road.com/atv/article/articleDetail.jsp?id=191530

You'll notice in the second picture of the Off Road article where they drilled through the bottom of the oil passage in the clutch cover. They fixed this by inserting a small brass plug. That's an option, but my method is much cleaner and you'll never have to worry about that plug coming loose and grenading your newly rebuilt engine. Just tap, check, grind; tap, check, grind, until the fitting screws in snugly and faces forward (important, because you won't have clearance to turn it once the cover is re-installed).

[F-16Guy]

Originally posted by aDviSol2y
F-16Guy, Can you come install the cooler for me? LOL!
Sorry, no plans to go to PDX until December at the earliest!

[F-16Guy]

Originally posted by thebig450es
Thats great help F-16Guy, has anyone made detailed instructions with pics yet, ive been searching to no advail. Id like to do the perma cool and the spal fan before the engine work is done. Thanks
If you do the SPAL fan, how about adding this?
http://www.jegs.com/p/Flex-a-lite/Flex-a-lite-Variable-Speed-Control-System/1017699/10002/-1
Just a suggestion, but I thought it would be a good addition to the cooler and make the fan more user friendly (not to mention be easier on the electrical system). You could plumb a "T" into the cooler inlet hose and install the bung for the sending unit. The rest is just basic wiring. If you've got money to burn, I guess. :cool:

[aDviSol2y]

Originally posted by F-16Guy
These were posted in another cooler thread and look to be the best instructions out there:

http://webpages.charter.net/tandrus4700/400exCoolerMod.pdf
http://atv.off-road.com/atv/article/articleDetail.jsp?id=191530

You'll notice in the second picture of the Off Road article where they drilled through the bottom of the oil passage in the clutch cover. They fixed this by inserting a small brass plug. That's an option, but my method is much cleaner and you'll never have to worry about that plug coming loose and grenading your newly rebuilt engine. Just tap, check, grind; tap, check, grind, until the fitting screws in snugly and faces forward (important, because you won't have clearance to turn it once the cover is re-installed).

The first pdf you posted is probably the best instructions I have seen. I am actually not feeling to worried about installing this now. It really does not seem that hard. Thanks for the help!