CruzinImage GT750 Piston Question

[jaycee69]

Hi all! i was recently looking at the cruzin image pistons on ebay for a set of 3 and noticed that the circlips in the picture are a snap ring. i was wondering if when people use these kits to they use genuine suzuki Wire circlips? or do you just use the snap rings they give you?

[oldjapanesebikes]

I toss the supplied gudgeon pin clips and use Suzuki ones - other than that, I like the product and have now installed several sets (GT750, GT550 and T500's).

[Vintageman]

oldjapanesebikes,

Did you do any comparisions? I heard they are a little heavier (stronger skirts?). Lengths the same? Modern (thin) rings?

What did you use for clearance if you bored OS?

[Coyote]

What did you use for clearance if you bored OS?

Say what? Clearance for what?

I personally hate the OEM clips. Getting them out is fairly easy, but putting them back in is nearly impossible without bending and deforming the clip. A snap ring sounds like a much better idea, BUT, you cant use a snap ring on a stock piston. The groove is not deep enough nor is it square cut like a normal snap ring groove. Just my opinion,

[jaycee69]

Are the cruzin image square cut for the snapring? or are they round for the suzuki ring?

[oldjapanesebikes]

Did you do any comparisions? I heard they are a little heavier (stronger skirts?). Lengths the same? Modern (thin) rings? What did you use for clearance if you bored OS?

If you did a search of this board for Cruzinimage you'd find the answers eh ? This is a pretty old topic and lots of folks have commented on it both pro and con. To your questions, and keeping in mind it's free advice and so worth every cent you've paid: yes, no, yes, yes (or at least more modern than the tractor rings in the first T500's - they are pretty much the same as period Suzuki ones) and standard (about 2 thou if I recall - check the shop manual - its available all over the place, but I have the Suzuki one on line at this link).

[JoostGT]

I have a set of those pistons waiting installation, if you want detailed measurements, comparions or pictures just ask

In my opinion they are pretty good, especially considering the price. They are almost exact replicas of the original pistons bar the Suzuki logos. The gudgeon pins are thicker walled so they are heavier than the stockers. Also, there is more room for the small-end to move laterally. Early 750s were located with shims at the big-ends, later 750s located at the small end, but on the cruzinimage pistons this is almost 1mm too wide. I was thinking about installing extra shims to solve this, but haven't really went and bought some.

[Vintageman]

My recall I don't think it was was said "why" they were heavier (I'll search again).

Thicker skirts not a bad idea given what has been said about OEM failing. But, that may only have been old style T500 pistons.

Would be nice to have taken some measurements (send me if you have). If no physical diff. then it can also be Al properties.

Touchy old post... touchy topic still!

Clearance. Piston to cylinder. I know what is published. And, know that is for Suz piston only. Aftermarket supplier's may and have used different aluminum compositions be it cast or forged. I know "Art" supplier was one of Suz oem for example and no worries here

But, people have used aftermarkets and tried to hold to OEM and they have seized. I don't mine saving money but, I have a lot invested so far. A little more clearance is OK as long as you know it is needed. So, was hoping someone would have said what they used if over size (OS) application only. That's what I plan to do. If one just honed out STD size that really doesn't count.

Hope that clarifies my sincere questions

[tz375]

Quality seems to be comparable to OEM but I have no way of testing the metallurgical composition, so that's a little subjective.

We do know that stock Suzuki pistons crack and they also seize. I have just removed a set of badly smeared OM pistons (outers - center was fine) and the prior engine had a couple of cracks, as did several others I have worked on.

Are CruizinImage any better, I have no idea but for average street use, I would expect them to be OK.

A more pertinent question is about circlips. If the pistons are machined for flat clips, it would normally be better to use those clips.

[oldjapanesebikes]

Touchy old post... touchy topic still!

It isn't touchy at all really - being a old guy, and well into my dotage I just sometimes get a bit disappointed when people don't appear to do their homework. This board has been running for many years now and there literally is a gold mine of data available if people would search first, and ask questions later eh ?

I've used stock clearances and so far at least had no issues at all. And the supplied circlips on the last few sets I've put in were not squared off - they were round. It is possible the latest ones are different - perhaps someone can confirm that. As well, I tried them but the material seemed to loose its tension (seemed to be mild steel) which made me unsure of how well they would last when in service, so I went with the Suzuki standard ones. And the gudgeon pins are actually very close to being the same wall thickness as the new replacement Suzuki gudgeon pins under part number 12151-13A00-0A0.

[Rhencullen]

This board has been running for many years now and there literally is a gold mine of data available if people would search first, and ask questions later eh ?

Good point Ian - but then, on the other hand, it's nice to occasionally have a few posts on the board

I do appreciate your input however, and it is very often the same few regular contributors answering the questions. This is the case on every forum that I'm a member of - but on the UK boards there is often more 'real life' interaction to compensate for that, with it being a smaller Isle.

[Vintageman]

This is an interesting difference ->

Also, there is more room for the small-end to move laterally. Early 750s were located with shims at the big-ends, later 750s located at the small end, but on the cruzinimage pistons this is almost 1mm too wide. I was thinking about installing extra shims to solve this, but haven't really went and bought

.

Pistons coming out of Australia now ala eBay

Wossner (fairly recent not much physical data I can find)

P. Miler had some Wiseco's recently (try and find numbers and see if offered direct or special order quantities)

Would be nice as we use these various suppliers overtime we gather just physical quantitative facts about them and compile data in a common format for each for future query,

Separate matter, but agree actual miles run in engines is great qualitative fact

[Coyote]

I can only touch on 2 things here. The wrist pin wall was increased by the mother ship. The reason for this was that in rare instances, there was some problems with the wrist pins shearing off.
I had a set of Wiseco pistons for the GT550. The paperwork included in each box recommended .002 clearance.

[Suzukidave]

I remember the Wiseco's had to set a bit loose for expansion compared to the stock pistons , i think i would use the stock clearance http://www.oldjapanesebikes.com/mraxl_G ... /sr26.html" onclick="window.open(this.href);return false; .

[Vintageman]

0.002" is unusually tight for a forged piston at 61mm. more like 0.003" - 0.0035" I would have expected from wiseco

Wiseco at times included that little paper giving recommended clearance but, included a few ranges based on Piston diameter: not just the one they stuffed in the box. Are you sure?

I don't understand the idea with GT750 small end tightened up side to side and big end moves much. They had their reasons 1mm larger spacing in Cruzer's piston may not be an issue right off, but over run time? Maybe not either if concept was not critical.

Each washer has a small step as we have seen that is to go over needle bearing. That is very shallow

I did note on my bike the wrist pin had slight groove where the washers are setting over pin. And you can also tell by the thinness of the line things did not move side to side much at all. And, at that wear rate it would be >200K mile before it was 1/4 way through. So thicker wrist pin no added value I can see, Nor would it really hurt either.