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Discussion Starter #1
Figured this belongs in advanced tech since most general techies have not run into the following issue.

Purchased (many months ago) Wiseco pistons to install in a junkyard 6 bolt engine. Got the 7.8:1 pistons.
Cleaned up the block per usual. Had block match bored & honed to each piston. Reinstalled oil squirters and crank.

Tried installing the pistons but noticed the oil squirter makes contact with the bottom of the piston!

Fairly sure the piston is installed correctly because i used the stock pistons to go off. When stock pistons are held with the arrow pointing towards the front/timing belt end of the engine the larger valve cutouts (intake valves) are at the left side (towards the rear of the vehicle if the engine were installed in the car). Installed the Wiseco piston in the same manner and piston hits the squirter and does not allow the crank to rotate.

Questions:

Did I install the piston correctly? Install the oil squirter correctly (don’t think its possible to screw that one up) or are they specific to each hole?

Has anone else who used Wiseco pistons experienced this problem and if so what did you do about it?

Are these pistons designed to be run without the squirters? or are the exhaust valve pockets bigger than the intake pockets for some reason. I assumed the new pistons would be like the stock ones which have the intake pockets larger than the exhaust pockets.

Guess i'll call the shop i bought them from tomorrow but wanted some input first from the (advanced) dsm crowd first.

Thanks in advance for any help.

Johnny
 

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Discussion Starter #3
update

Since nobody has been able to provide input on this I'll just add to this thread myself in case anyone else comes across this problem themselves.

Called the guys at Race Engineering (http://www.raceeng.com) where i bought the Wiseco pistons. According to them there were some year to year variations which will cause this problem. They recommend clearance'ing the piston but drilling a dimple. This sounds difficult to me and makes me wonder about balance.

I measured the depth of the piston in the bore when it contacts the squirter. Measured again with the squirter removed and piston at BDC (verified with a dial indicator). The difference between the two is approx 1.5 mm.

Looking at the squirter it looks like it can be safely bent about 2-3 mm (in the piston bore direction) to eliminate the interference. Actually, it is a little trickier than that because just bending it will cause the oil to be squirted out at a different angle than original so it will take a little tweaking. If it feels difficult to bend i might use an oxy torch to heat it and slowly cool it. That might be tricky too because the tube appears to be brazed onto the mounting boss.

Other option is to cut 2-3 mm off the tip. There is enough meat there. however, the orifice might be smaller than the tube ID so it would be smart to use a needle gauge or jet drill to measure the orifice ID before cutting. If the ID needs to be reduced after cutting you could braze the tube shut and drill a new orifice of the correct size.

Will post again after attempts to fix interference. Maybe someday someone will use the search button and this will help them.

Johnny
 

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uh oh

I'm very interested in hearing about this as I have a set of Wiseco's waiting to be put into my motor.

Please do keep us informed...

BTW, I would suggest calling Wiseco, they have been very helpful to me and would probably help you out as well.

Thanks again
 

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Discussion Starter #5
Didn't call Wiseco because i figured the shop Wiseco recommended i buy my pistons from probably has more experience with installation issues than Wiseco.

Bent the piston squirters and installed pistons tonight. Did not bend them in the bore direction because was not sure if they would then interfere with the crank weights. Instead bent them about 3/8" sideways to clear the wrist pin boss. clamped them in a vise at the tip end (short let of the 'L' is clamped) and just bent them by hand. appears to be a mild steel tube.

not much clearance but hopefully enough. now wish i'de bent them a little more to maybe 1/2". there's no way to easily measure the clearance. figured if i can see through the gap then should be ok. doesn't drag when rotating the crank. hopefully the bend won't 'relax' or crack. i'm sure running the engine for the first time will be nerve wrecking.

good luck with your engine rebuild. you using eagle rods too? what CR did you go with?
 

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bending the squirters is asking for trouble. clearancing the piston is the proper way to do this. you have to mock assemblt the piston and rod and mark on the piston were it wants to contact. then just grind a slot on the bottom of the piston.
keep in mind those squirters can vibrate. you need 4-5mm clearance.
 

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call wiseco
they are good people and deal alot with racers

ps my dad works there
they dont care were u bought them just that u bought theres and not some ones eles pistons

tim
 

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You have forged pistons, you really should just remove/block off the oil squirters.

I see another engine swap in your very neer future. Be sure you have an oil pressure gauge.
 

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Yeah, I would call Brian over at Wiseco in the automotive division, he is VERY knowledgable and really ood to deal with.......
 

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firepower said:
You have forged pistons, you really should just remove/block off the oil squirters.

I see another engine swap in your very neer future. Be sure you have an oil pressure gauge.
What do you mean by that? I'm going to install a set of Ross 8.5:1's in my motor and I've never heard of anyone removing the oil squirters just because you're using forged pistons.
 

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oiler option

Hi there, sorry your having a problem w/ you pin oiler notch. We've usually had good results w/ nearly anyone's engine, but there are always flyers. It's pretty hard to know how they go in w/ the pockets looking more or less symetrical. If it helps, our parts have a .040 pin offset to keep piston slap to a minimum. Make sure this offset is in the same direction as the factory piece. On the Wiseco "stocking" piston (k548/549 series), the skirt profile is cut higher in such a way that the notch isn't necessary (usually). I've tweaked the squirters on other engines by putting a piece of wire inside before the tweak-then pulled it out keeping the tube from caving in. The best way to do it though would be to dremel the skirts of the piston. It's a little scary for the novice, but you won't hurt anything. We're looking for .060 clearance min. which is 1.5mm. That covers the rod stretch and issues w/ stroke. After placing the notch in the skirt, debur the skirt to keep from scratching cylinders. The difference in gram weight will be at most a few grams and as long as you're half-way good with a grinder-they'll be matched from piston to piston. I won't give you a range to hit, because you'll still be doing excellent compared to the factory pistons which are all over the map. The 4 cylinder engine configuration makes this very forgiving. Thanks, email me at [email protected] for further assistance.
 

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Back to this blocking off the oil squirters because of using forged pistons. What makes you sure that you can do this . . would it have other side effects? The reason I ask is because i have a 6bolt NT block sitting around that I was thinking of using but decided against because its missing the squirters. . . . . Please provide us with more info :):)
 

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Discussion Starter #13
Brian: what is your opinion on removing the oil squirters when using the Wiseco pistons? My car is not a drag car, its a daily driver with some autox use. My shifter kart is for racing (and has a Wiseco piston too :)

The interference is not with the skirt but the tip (of the oil squirter mounted on the block) interferes with the boss around the wrist pin area on the pistons. In my case i would have to make a hole/slot slightly larger in diameter than the squirter tube because there is not much interference. that is why i just bent them, seems easier and doubt vibration will be a problem with a couple millimeters clearance. I'll probably use a piece of wire if i bend them more to prevent the tube from collapsing. Any input on this Brian?

The cleanest solution would be to remove the squirter assemblies, remove the squirter tubes from their mounts, shorten the tubes and then braze them back onto their mounts.
 

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oil squirters

good luck with your engine rebuild. you using eagle rods too? what CR did you go with?
Yeah I'm using eagle rods too, did you notice that the eagle rods don't have the small hole branching off from the journal? On the stock rods this sprays oil onto the cylinder walls. I guess that it is not needed...... I hope

My Wiseco's were a custom order for Voodoo racing, with the Mitsu 4-layer headgasket the CR is ~8.4:1 (assuming zero deck height)

I would not remove the oil squirters, Forged pistons or not the piston is still subjected to the same amount of heat and in the forged case you'll have more expansion. Keep the squirters, they are added insurance.....IMHO as always
 

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From what I gather, since forged pistons withstand heat much better, the underside no longer needs the cooling of the squirters - it almost becomes redundant... not to mention the 2g squirters suck anyway.

-Craig
 

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squirters part 2

As for necessity, squirters are needed mostly for endurance racing such as our IRL or Winston Cup pistons. Prolonged lean conditions is what takes the hardness out and eventually cracks a piston or lifts a ring land. A piston leaves Wiseco w/ a certain hardness based on our forging and heat treating process. Most U.S. based piston companies do not do their own forgings and don't have control over this process. As long as the mixture is correct though, many other turbo engines go for a long time at high power without needing them. The conventional wisdom of removing them altogether has not proven to be a detriment in your application, but squirters are a nice touch when they're there. I believe your decision to keep them with as little tweaking as you've done is a good one. As you've described it, your 2mm clearance from "tweaking" is more than enough and vibration won't be an issue. I think you're done.

For future issues, if the angle of the oil passage in the squirter assembly makes it possible, I'd take them off-run a piece of proper gauge welding wire in them and clip or grind the tips a bit, running the wire out the tip and cleaning them to keep them free of debris and collapse.

If ever necessary though, our pistons are strong and the area the tip contacts the inner part of the pin boss is left w/ more material than is necessary. As long as 5mm of material is left around the pin bore in any one spot, the piston will be fine. Proper cartridge roll work to prevent stress risers is always a nice touch.

Thanks, Brian Nutter-Wiseco pistons
 

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When balance shafts are eliminated these moters pick up a high frequency vibration. Just put your hand on the valve cover at idle and you will see what i am talking about. Things that you know you tightened misteriously come loose. This is just words of wisdom from experience. I ran a stroker with 2mm clearance of the squirter. and it hit the piston. i can only attribute this to vibration.
As far as eliminating them. I personally wouldn't dream of it. Aluminum is the best absorber of heat. Oil squirters are there to remove some of the heat. Mitsu didn't put TWO squirters in there just for fun. And keep in mind we're running two and three times the original HP output of these motors. Dont you think that puts more heat in the piston?
just my 02.
 

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SQUIRTERS part 3

Thanks for bringing that up. I believe his decison to tweak the squirters was a good one, but there are some additional points I should bring up. I didn't mention before, but for you guys considering stroker's, We're coming out with some new pistons for the stroker 4g63 and a bigger volume 4g64 w/ 63 head combination. When the piston goes up another 6mm it will come down another 6mm making the problem w/ squirter clearance problem worse. Luckily when we make a compression height shorter (not to be confused with compression ratio), we subtract a certain ratio from the bottom of the skirts as well as shorten the top. I hope this compensates a bit. It may be impossible for some to tweak the squirters enough and some may HAVE to get rid of the offending squirter entirely. The important thing to consider is the volume of the oil slung off the crank is many times more what the volume of a .040 orifice at 35 psi. Especially the relative closeness at bdc to the main and rod bearings.

I'll try to address the interference issue you had. As for your particular engine, piston rock was most likely caused the problem. A piston has a taper built into the skirts from top to bottom. When a piston is bdc, the bottom of the skirt can drop out of the cylinder to the point where your cold .003" lateral clearance becomes .005 or .006 very quickly. This could be the root of your problem rather than a vibration. If you still have the piston, you may notice a Halo shaped wear pattern at the bottom of the skirt to verify this. If you'd like to help me a bit, give me the measurement the piston drops out of the bottom of the cylinder and I'll make sure we raise the break point of our taper to the point where rock won't be an issue with our new stroker part #..... On to your last point about heat- Heat is horsepower, but a piston crown can be cooler at 600 horsepower than it is at 200 horsepower. Some of our customers are making upwards to 266hp per cylinder without squirters. It's mostly a function of mixture as the cooling effect of fuel on the intake stroke takes out what is built up during the power stroke. Also, we try to make a piston w/ proper taper and cam to come as close to the cylinder under running conditions. Most of the heat is bled out of the crown through the rings and quite a bit comes out through the skirt to oil to cylinderwall relationship when the fit is good. Please email me at [email protected] if I can be of further assistance. Thanks, Brian
 
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