Turbo and Supercharger discussion
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By BEARSOL
#355238 I recently did a Vitara build with H beam rods. I did a stock bore piston so 75mm bore and piston. I noticed I seem to have a chatter from the top of the motor. When I say chatter I mean it sounds like a Diesel. It quiets as it warms up (I'm thinking because of the pistons warming and expanding). I checked to see if maybe a bearing failed and there are no metal shavings in the oil and I have double checked the valve train for severe lashing and it seems right on. The only conclusion I can make is that I have piston slap from the Vitaras. Some of the research I have done says this is normal, some says it needs fixed. I am leaning toward needs fixed. My question is has anyone come across this in a vitara build on a D16z6? Do you have any advice on it if so? I also have an overheating issue but I am not sure if it is related or not. I only overheat when driving not at idle.
User avatar
By EconoBox
#355240 It is true that a lot of Vitara piston builds get 'piston slap' on warm up but the noise goes away completely once they reach operating temperature.

If the noise is not going away you have something wrong. More than likely it is piston to cylinder wall contact. I do know a lot of Vitara guys just let it run this way and the motors seem to last a little while but it does cause excess wear.

A lot of people do these piston/rod swaps without knowing how involved of a process it is to do correctly. Were the cylinders measured to make sure they are round? Were the cylinders measured to make sure the engine had never been bored over previously? Did you measure piston to wall clearance? Did you measure your rings? Did you use standard length H beam rods or modified ones for a Vitara build? What kind of locks are on the wrist pins and are they installed correctly? What weight oil are you running? What operating temperature is the motor at?

Honestly the best way to do Vitara's is to use the extended Rods and use 75.5mm Vitaras. You take the pistons to the machine shop with the block and they will mark the pistons 1,2,3, and 4 and match each cylinder exactly to each corresponding piston. I have done a few and put them together using Honda recommended tolerances and never had this issue.
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By BEARSOL
#355241 I had the bore checked and it was in good shape and it was a factory bore. I did not measure the piston to wall clearance but knew I had a 75mm piston for a factory bore. I modified the piston to fit the rod for the rod/piston fitment. I did not use a modified h-beam rod for the build. I did not check the ring measurement. locks are the c-clip style retainers; not sure exactly what they are called but I believe they were installed correctly. I am running the factory specified oil. at standard operation temp it does quiet down a lot. I was thinking about getting a hold of a camera to see if there was damage being done to the cylinder walls due to the slap.
User avatar
By EconoBox
#355242 The camera is your best bet at this point. The Vitara pistons aren't designed for Honda motors and I know the standard 75mm ones run a little loose on Honda engines. For future reference all of those tolerances to need to be measured.
User avatar
By BEARSOL
#355243 great thanks for the info.
User avatar
By teal_dx
#355250 Hey Paul, I have a camera that may work for you, if you want to borrow it.
Give me a call tonight.

Without hearing, I'd also bet piston slap. My old D15b7 had it and it sounded like an old compressor if I drove the car without letting it idle for a couple min.
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By BEARSOL
#355337 I have a few pics of my cylinder walls. They do not look good to me. looks like some front and back scaring. Upon further review from other research I have done I have found the same as you were saying. it seems as though the 75mm build from a factory bore will give a honda owner Piston slap in most cases. it seems as though the only way to not have this problem with the 75mm piston is to have it sleved and then bored to fit the 75mm piston. just an FYI so no one else wastes 3+ months of work. If you would like I can add the photos if you all want to have a look see.
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By BEARSOL
#355342 here are some pictures. let me know what you think. If you look you can see oil as well on the pistons. This was not coming from the turbo either. not good to me.Image
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User avatar
By EconoBox
#355400 Yep definitely an issue there... It's up to you whether or not to just run it until it breaks. You'll want to have it bored and honed for new pistons if you fix it. If I were building a boosted SOHC I'd go with something like these and have the machine shop use them to bore and finish hone each cylinder to spec (And size your rings correctly) Good luck!

http://www.ebay.com/itm/CP-Forged-Pistons-WITH-RINGS-Civic-D16Z6-10-5-1-75-5mm-/391067712814?hash=item5b0d73bd2e&vxp=mtr
User avatar
By BEARSOL
#355424 where did you get your SRP's? the most common I have found have been CP's but they are around 6-650. if I can save the scratch I would like to with this (at one point) being a budget build. lol
User avatar
By teal_dx
#355428 I bought them on ebay in the mid 2000's, some guy bought them new and never used them in his build, so I scored them for something like $350.

I found the 75mm SRP's for $430 shipped, but not seeing any results for 75.5mm. I wonder if they discontinued the 75.5mm ones :?
By jefferydclark
#355432 It's not an issue of they slap. Some of the highest hp cigars builds are running 75mm pistons with worn engine sleeves. I ran mine with piston slap and had no issues at all. My second cigars build is due to hit the streets this spring with 75km vitaras yet again. There is a noticeable difference in tone of piston slap vs rod knock so I don't see why there would be a reason to worry.
By jefferydclark
#355433 My sleeves had a little markings on them but you couldn't feel the grooves.