Piston Question

[smorris1]

I am putting a 11:1 piston in my 400ex. Do I need to drain the oil before I take the head and cylinder off? If I do have to drain the oil, is Klotz MX4 synthetic oil ok to use when I put it all back together?

[XXXRACER165]

No you don't have to drain the oil and Synthetics are a bad idea for break in.

[smorris1]

The reason I am asking this is because I have klotz mx4 in it right now and I dont want to drain it if i dont have to. If using a non synthetic oil is recomended for break in, then I guess I will have to drain it anyways.

[drew416ex]

Nope, cant use oil for break in but afterwards is fine. You can also run no base gasket for a little added compression. Unless you have a super big cam there should be no clearance issues and you can still run 93 octane.

[smorris1]

Exactly how should I break it in? What is the procedure?

[F-16Guy]

I wouldn't advise using no base gasket. The oil passage for the top end runs from the case to the cylinder and up to the head, and the base gasket normally seals the faying surface between the case and cylinder so that the pressurized oil stays in the passage. If you eliminate the base gasket and just use a sealant like Yamabond, you run the risk of having sealant squeeze out into the passage when you torque down the cylinder. That squeeze-out may block the passage at the cylinder or chunks may break loose and find their way to one or more of the cam journals. Either way, not good. The one safe way to do it is to run an FST style external cooler that routes the oil away from the cylinder oil passage all together.

To answer the question: Why risk a new build for $15 worth of oil?? Just drain it and run a quality standard oil for the first several tanks.

[F-16Guy]

Originally posted by smorris1
Exactly how should I break it in? What is the procedure?
It depends on what you're doing. If you're installing a new cam, you need to make sure everything is ready before start-up (oil is full, carb is jetted for the new mods, etc.). When breaking in a new cam, you want to start the quad and immediately run it at a very high idle (approx. 2000-2500 RPM). Once you verify that there are no leaks or major problems, you can ride it around lightly, keeping the RPMs above 2000 for at least 20 minutes. After that, the cam should be properly run in and you can then let it idle. From that point, I usually just start out easy with no lugging or hard revving, and ride progressively harder through a few tanks of gas.

If you're just doing the piston, just ride easy at first and then ride progressively harder throughout the first several hours or couple tanks of gas.

[smorris1]

Alright thanks. I am just breaking in a new piston. It already has a hot cams stage 2 cam but thats already broken in.

One last question, what oil do u recommend for the break in?

[Ry007]

I'd just use something like Honda GN4 for break in. Then run what you like. Hope that helps.

[drew416ex]

Originally posted by F-16Guy
I wouldn't advise using no base gasket. The oil passage for the top end runs from the case to the cylinder and up to the head, and the base gasket normally seals the faying surface between the case and cylinder so that the pressurized oil stays in the passage. If you eliminate the base gasket and just use a sealant like Yamabond, you run the risk of having sealant squeeze out into the passage when you torque down the cylinder. That squeeze-out may block the passage at the cylinder or chunks may break loose and find their way to one or more of the cam journals. Either way, not good. The one safe way to do it is to run an FST style external cooler that routes the oil away from the cylinder oil passage all together.

To answer the question: Why risk a new build for $15 worth of oil?? Just drain it and run a quality standard oil for the first several tanks.

I have never had a problem running no base gasket. And also, powerroll has a special sealant that will not block oil passages like silicone would.

[smorris1]

Yeah thanks again for all the info guys. I am definitly going to use a base gasket tho. There is a reason why its there in the first place.

[drew416ex]

Originally posted by smorris1
Yeah thanks again for all the info guys. I am definitly going to use a base gasket tho. There is a reason why its there in the first place.

Thats understandable. I just didnt use one becuase most 11:1 pistons arnt a true 11:1. Removing the gasket gets it a lot closer to this.

[smorris1]

Yeah thats what I heard too. I heard its the wiseco 440 pistons that arnt true to their compression ratio.

[F-16Guy]

There is a big misconception about Wiseco compression ratios. If you use the thinner XR400 gaskets, the CR is almost dead on. The only piston that had issues was the flat-top 89mm (440) piston. Getting rid of the base gasket doesn't do as much for compression ratio as it does for getting the deck height correct for the flat top piston. Long story short, most people are just repeating what they've heard about Wiseco pistons without really knowing what they're talking about. If you have anything but the flat top 89mm piston and you used XR gaskets, the CR is correct. Incidently, the flat-top piston is actually better for making cooler, more efficient horsepower as long as you take the time to build the engine correctly (set deck height, compression ratio, etc.).

whats the stock compression ratio? my brother got a 10:1 wiesco and i think thats higher compression than stock

[drew416ex]

Originally posted by F-16Guy
There is a big misconception about Wiseco compression ratios. If you use the thinner XR400 gaskets, the CR is almost dead on. The only piston that had issues was the flat-top 89mm (440) piston. Getting rid of the base gasket doesn't do as much for compression ratio as it does for getting the deck height correct for the flat top piston. Long story short, most people are just repeating what they've heard about Wiseco pistons without really knowing what they're talking about. If you have anything but the flat top 89mm piston and you used XR gaskets, the CR is correct. Incidently, the flat-top piston is actually better for making cooler, more efficient horsepower as long as you take the time to build the engine correctly (set deck height, compression ratio, etc.).

Ok yeah, im a dumb *****. I dont know what im talking about. I mean, only 8 out of the 10 400ex engines i have built didnt have the right CP when it came to the 11:1 wiseco. But i guess im one of those people that dont know what they are talking about.

[drew416ex]

Originally posted by FoxHondaRider
whats the stock compression ratio? my brother got a 10:1 wiesco and i think thats higher compression than stock

Its either 9:1 or 9.1:1, cant remember.

so even 10:1 is a higher compression even if people are saying "its not exact" or "its not right its less than it says". in reality the carbon build up on pistons raises compression even in cars.

[smorris1]

Yeah I think stock is 9.1:1

[GPracer2500]

Originally posted by drew416ex
....8 out of the 10 400ex engines i have built didnt have the right CP when it came to the 11:1 wiseco....

What compression ratio where you getting? Why was it 8 out of 10 instead of 10 out of 10?

the way i look at it even if theres a greater amount than stock theres HP being gained. Not only do the Wiseco raise compression (maybe not as much as it says) but they are a hell of a lot lighter than a stock piston which means quicker revs. Take a Wiseco and take a stock piston and weigh them or simple just pick the 2 up and you will easliy notice the Wiseco is lighter

[drew416ex]

Originally posted by GPracer2500
What compression ratio where you getting? Why was it 8 out of 10 instead of 10 out of 10?

The 10 that were built were within 4 years of each other, so the pistons were made at different times. Im assuming thats why they werent all the same. Only two of them had an 11:1 compression. The others were around 10.5:1 to 10.8:1. Not a big difference, but a difference.

[smorris1]

Even if they are off by a .3 of a compression, I dont think your going to notice it. Like FoxHondaRider said, its still going to make noticably more power than stock.

exactly, they are lighter so thats a gain right there with quicker revs. then even a little bit more compression its still going to make more HP than stock and you will feel it

[F-16Guy]

Originally posted by drew416ex
The 10 that were built were within 4 years of each other, so the pistons were made at different times. Im assuming thats why they werent all the same. Only two of them had an 11:1 compression. The others were around 10.5:1 to 10.8:1. Not a big difference, but a difference.
You cc'd every engine you built? My build was very close to 11:1 both times I've rebuilt it, and so was a 406 that I built for a friend a couple years later. It seems strange to me that Wiseco would keep messing around with a piston that has been around for quite a while. If you thought there were problems with them, why would you keep using them?? I still think that a lot of the claims about Wiseco pistons being way off are from people not qualified to make that assertion. Let's face it, most of the people on this site couldn't tell you how to get an accurate compression ratio in the first place.

yeah it seems odd that so many that you are claiming are off what they say. maybe you had a leak somewhere or something idk

[F-16Guy]

Originally posted by drew416ex
I have never had a problem running no base gasket. And also, powerroll has a special sealant that will not block oil passages like silicone would.
I've personally never heard of anyone having a problem, but the potential exists. All it would take is someone to goop a bunch of make-a-gasket on there "just to make sure it doesn't leak", and you'd have a ton of squeeze-out pouring into every void. I've never heard or read anything about the Powroll sealant, but it sounds like a good idea if you're going to go that route. Like I said, you can also bypass the passage completely with the external cooler, which was an awesome addition to my 416.

[drew416ex]

The 8 that didnt quit measure up were made before the last two i built. I dunno, maybe they figured it out and made some adjustments. The last two i built didnt have to have the base gasket removed to get 11:1. I do know that 99% of the engine builders (car or motorcycle), say that wiseco has much greater tolerances than others like JE. Not sure why though. And nothing is wrong with wiseco, i used it in mine for several years.

[drew416ex]

Here is the stuff from powerroll. ITs made by Hylomar.

http://www.powroll.com/tech_specs_tools.htm

[smorris1]

If I were to run no base gasket, the Powroll sealent is the only thing I would consider using. Still tho, I dont know if I trust running no base gasket.

[m36indiana]

hylomar is some good stuff, we use it on building airplane engine as a sealant, so im sure it will hold up to the heat of an ATV engine

[smorris1]

I just checked out that link for the sealent. Its not quite as expensive as I thought. Which one would u buy?

[drew416ex]

Well its up to you. I understand your concern. I havnt run it on mine for years and neither have my friends and we havnt had any trouble.

[m36indiana]

all of them are good, we use the aerograde

[F-16Guy]

Originally posted by drew416ex
The 8 that didnt quit measure up were made before the last two i built. I dunno, maybe they figured it out and made some adjustments. The last two i built didnt have to have the base gasket removed to get 11:1. I do know that 99% of the engine builders (car or motorcycle), say that wiseco has much greater tolerances than others like JE. Not sure why though. And nothing is wrong with wiseco, i used it in mine for several years.
Wiseco and JE are owned by the same parent corporation, so you'd think that the quality control would be pretty uniform, but maybe not. From the reading I've done, the 440 piston was WAY off. It was advertised at 11:1, but with no machining or modification, it ended up under 10:1!!

[drew416ex]

Maybe its like craftzman and companion tools. Sears has both, but one is a little better quality. idk

[boosted3g]

I would trust hondabond ht more than hylomar. Never had any good experiences with the stuff. I seemed to blow more headgaskets on the racecar when i used it.

[smorris1]

I didnt know wiseco and je were owned by the same company. What company is it?

[GPracer2500]

Originally posted by smorris1
I didnt know wiseco and je were owned by the same company. What company is it?

Performance Motorsports Inc. (http://www.doverpmi.com/Index.html)

....and PMI has a parent company of it's own--Dover Corp. Sometimes it's surprising how many companies fall under the umbrella of the same huge corporate conglomerate.

[smorris1]

So when I get the 11:1 piston I am def running premium all the time. Is using a power additive like klotz nitro a good idea?

[project400ex19]

Originally posted by F-16Guy
I've personally never heard of anyone having a problem, but the potential exists. All it would take is someone to goop a bunch of make-a-gasket on there "just to make sure it doesn't leak", and you'd have a ton of squeeze-out pouring into every void. I've never heard or read anything about the Powroll sealant, but it sounds like a good idea if you're going to go that route. Like I said, you can also bypass the passage completely with the external cooler, which was an awesome addition to my 416.

did you notice a difference in oil temps with your oil cooler kit? also how much did it cost?

[smorris1]

Yeah what is the oil cooler kit? Is it a bigger oil cooler or a whole new internal engine mod?

[drew416ex]

Its a larger cooler kit that four stroke tech makes.

[F-16Guy]

It's actually a cooler made by Perma-Cool, P/N 1008 Universal ATV Oil Cooler Kit. It is nearly identical to the kit sold by FST except that you'd have to make your own grill. I made my grill from an $8 piece of expanded steel from Home Depot and then mounted the cooler to that with a $5 universal transmission cooler mount kit from Checker Auto Parts. This cooler is separate from the stock cooler and does not affect the function of the stock unit; it is supplimental. Although there is a little more work involved with installing this cooler, the advantage is that it picks up the oil right after it goes through the filter, routes it to the cooler, and then feeds cooled oil directly to the cam, bypassing the extremely hot passage that runs up the inside of the cylinder wall. To install it, you will have to plug the original oil passage with a check ball that is provided and then have fittings installed in the right side crankcase cover and in the rocker cover. If you're good at drilling and tapping you can do the fittings yourself, but I would probably have it professionally done if you have any doubt. I never took oil temps before or after, but I think Mickey Dunlap claims an average drop of about 50 degrees, with the added benefit of cool oil going to the high friction, high heat Radial Four Valve valvetrain of the 400ex. Mine has been trouble-free since installed, and anything that will drop the temps by 50 degrees is money well spent.
http://www.imagestation.com/picture/sraid212/p43392a2bbe0e012056ff5f68addee751/ed623142.jpg http://www.imagestation.com/picture/sraid196/p2931137c0a8e27111cf9c1604cae15bd/f11a05e6.jpg http://www.imagestation.com/picture/sraid212/p8ddfc26f9f6198db3e1f494568d7f6d0/ed6231c0.jpg

[smorris1]

That cooler looks sweet. A drop in 50 degrees is huge! How much does it cost?

[F-16Guy]

You can buy the kit at Summit Racing (summitracing.com) for $69.99, and like I said, another roughly $15 for the grill material and the mount kit to mount the cooler to the grill. There are threads with pictures on here about installing the fittings if you search for them. You can also search the web, I believe there are some detailed instructions floating around out there somewhere. The cooler is nice because it bypasses that oil passage in the cylinder, so if you add the cooler when you rebuild, you can leave out the base gasket and get the squish band tighter without worrying about starving the top end of oil.

[smorris1]

Wow thats no where near as much as I thought it was going to cost! I might do that sometime down the road.