Topic: cruzinimage pistons for racing applications

[gschuld]

PEWE,

I picked up those pistons out of curiousity more than anything.  A number of forum members commented about the main disadvantage of these pistons for modest performance engines was the rather modest valve pockets depth limiting the use of higher lift cams.

Raising compression wasn’t much of an interest or concern at the time.  The only way to do it is to reduce effective chamber volume. The head shown is a severely decked head, down to the fins(Came to me that way from an old race engine I bought complete).  This would again reduce valve to piston clearance though.

No point in shooting for more than 10:1 static on a pump gas engine for the street, and for that a bit of head decking should make that possible. 

A friend has the pistons currently but hasn’t made a plan to use them yet.

George

[bwaller]

George, any idea what those chamber volumes are now?

[kmb69]

.....
I bought some pistons from CycleX last month, and while they look OK, I wasn't happy with the way they packed them, throwing everything into a plastic bag, then throwing that into a box and sending it off is about as bad as a Customer Service can get. It might have been a one off, but I thought it was pretty pathetic.
.....

I buy stuff from Cycle-X fair frequently and have never received anything poorly packaged.
That would be quite out of character for those guys based on my experience.
Their Customer Service is pretty damn good IMHO. Did you address this with anybody at Cycle-X?
Possible that Customs opened for inspection and just threw it back in the box?

Yeah....I have hundreds of transactions as I buy a lot of my valve-train parts from Kenny. I have always experienced well packaged boxes. If anything they are a bit overboard on the wrapping of parts. I'd say Customs as they don't give a $hit.

Nope, the box hadn't been opened, anything I receive that gets opened has a customs label attached that says it's been opened, and is re-sealed with special tape. I left them neutral feedback, as the pistons are still usable, just poorly packed. They've never attempted to contact me, so obviously they don't give a sh1t.   

Guarantee you Kenny gives a sh1t. Somebody(s) at Cycle-X is/are probably getting an a$$ reaming this morning. Out of curiosity, I looked that transaction up on eBay. "unclebill1313" is not their official Cycle-X store/seller. "unclebill1313" is where they sell obsolete, discontinued, scratch & dent, and/or open box stuff and it is managed/mismanaged by a couple of young guys at Cycle-X that are probably getting a tune-up this morning.

Hell of a price for that big bore piston set for $188, they arrived undamaged - all good? 

[gschuld]

George, any idea what those chamber volumes are now?

No idea yet.  Actually I haven’t had my hands on them as of yet.  Frankie has a gathering collection of my parts.  This head came on a 73mm motor (RC pistons, golden rods, RC 454 cam, CR33 carbs, etc). It came from Florida and made it as far as SC with Frankie so far.  He is going to send me up the head, cylinder, and pistons shortly for a closer look.

I’ll let you know when I CC the chambers when it gets in.  High teens I’d think compare to the +/- 22.5cc for unmodified factory k head.

I’ve never seen a head milled down to the fins before....😳

[PeWe]

George, the CR might not to be frightened up that much.
I had 836 where head chambers were opened up to 24.4cc and pistons for it. CR around 10 + something.
Pistons later replaced by others that should give CR 10.25 with stock chambers. 22,5cc
The result was less compression (difference noticed when using kick start) but it worked really well for street and touring. I would say a much better touring bike running cooler and almost same power as before. Cam was Action Fours SS-1 with not that high overlap.

My 849cc pistons arrived with no bad surprises and I have not found any issues. Perfect price US $185.00 with low shipping and customs made it to a must. My old 836 cylinder I mentioned earlier need them since bore/836 piston total clearance is 0.2mm without smoking.

//Per

[754]

Terry , did the pistons come fitted to a barrel ? Even then..easiest to put them back in the box.

Btw NitroHunter  did a 10.0 in the 1/4 mile with stock pistons and a turbo..  I would think quite similar in quality to CruzinImage slugs..

[Terry in Australia]

Guarantee you Kenny gives a sh1t. Somebody(s) at Cycle-X is/are probably getting an a$$ reaming this morning. Out of curiosity, I looked that transaction up on eBay. "unclebill1313" is not their official Cycle-X store/seller. "unclebill1313" is where they sell obsolete, discontinued, scratch & dent, and/or open box stuff and it is managed/mismanaged by a couple of young guys at Cycle-X that are probably getting a tune-up this morning.

Hell of a price for that big bore piston set for $188, they arrived undamaged - all good? 

Thanks mate, well even though CycleX ignored my Ebay feedback for the last two weeks, coincidentally this morning they messaged me as follows: 

"Good Morning Terry,
We heard/read about the quality that your package arrived to you in. We care about protecting the product through out the shipment and apperance. So reading your comments on the poor shipment, we wanted to reach out to you. We do everything we can to make our customers happy and to fix potential problems from happening again. Please let us know if we can do anything to fix your thoughts on this company.
Thank You Again
Cycle X"

I replied:

"Thanks for your concern, after reading your message and some of the posts on the SOHC4 forum regarding this issue, I inspected the pistons a little closer today, and discovered that 3 of the 4 have some damage caused by them knocking together in transit (I presume) and of some concern is one with what looks like a casting flaw (circled) on the thrust face of the piston? All 4 have various minor scratches and rub marks, which I wasn't really worried about.

The last picture is how the pistons arrived, I really can't understand how CycleX could let something like this happen, knowing that there would have to be some damage on arrival almost 10,000 miles later? While the damage is only minor, that casting flaw worries me, so right now I don't really feel confidant to install them in my bike in case one lets go? Have you got another set you can send me? Cheers, Terry."

Damaged CYCLEX piston by terry prendergast, on Flickr

Damaged CYCLEX piston 2 by terry prendergast, on Flickr

Damaged CYCLEX piston 1 by terry prendergast, on Flickr

Damaged CYCLEX piston 3 by terry prendergast, on Flickr

CycleX pistons 1 by terry prendergast, on Flickr

Thanks to your post I took a closer look at them tonight, and while the damage isn't all that bad, that one with what looks like a casting flaw is a bit of a concern, I guess I'll wait and see what CycleX do to fix this for me, I'm not really too keen to install that piston? Cheers, Terry.  

[TurboD]

None of those small "flaws" or "damage" will have any effect on performance or reliability, I should know I have used or reused my share of damaged or less than perfect pistons over the years and never had in problem. Many of the things I see in the pictures are not completely out of the ordinary to see from time to time.

As others have commented, at the price you got a pretty good buy, yes they could have been packaged better. Install them and go.

[TurboD]

Back to the OP's question. I have used a number of the cruzinimage pistons (as well as other parts). I have no concerns using them, I have installed them in mild street engines to wild turbo engines running more boost and making for power than many will see with these old SOHC engines, I have them in my automatic that has been hammered on pass after pass shifting and crossing the traps at 11,000 rpm without any issues. For a lot of people and applications they are a very good value.

[livefast_dieold]

Back to the OP's question. I have used a number of the cruzinimage pistons (as well as other parts). I have no concerns using them, I have installed them in mild street engines to wild turbo engines running more boost and making for power than many will see with these old SOHC engines, I have them in my automatic that has been hammered on pass after pass shifting and crossing the traps at 11,000 rpm without any issues. For a lot of people and applications they are a very good value.

Thanks! These are great insights

[slikwilli420]

You going to give them a try Riccardo?

[PeWe]

TurboD,
Nice 4-1 on the red! Which model of Vance & Hines fits the CB750? They never sold 4-1 to the SOHC as I am aware of.

[TurboD]

Its for a CB1100F #14001-P . With a slight tweaking on the head tube spacing they go right on.

[gschuld]

PEWE,

That 1100f pro pipe has also been Dragracer(Frankie’s) exhaust of choice for years on his red F model drag bike and his new bike in progress.

George

[MRieck]

George, any idea what those chamber volumes are now?

Probably around 21cc as that chamber looks like a late K.

[livefast_dieold]

You going to give them a try Riccardo?

Not anytime soon... maybe if the ones I've now failed

[Terry in Australia]

None of those small "flaws" or "damage" will have any effect on performance or reliability, I should know I have used or reused my share of damaged or less than perfect pistons over the years and never had in problem. Many of the things I see in the pictures are not completely out of the ordinary to see from time to time.

As others have commented, at the price you got a pretty good buy, yes they could have been packaged better. Install them and go.

Thanks mate, I think I said earlier that I wasn't worried about the little dings that happened in transit due to the poor packing, but the "flaw" looks like a tiny air bubble in the casting that's been cut thru when the rough cast Pistons were machined.

The good news is that CycleX responded to my reply, saying that they'll send me another set today. Cheers, Terry.

[markreimer]

I had CI pistons in my 350F. Utter crap in every way. I have cycle-x pistons in my cb750. Going on four years since I installed them, zero issues in any way.

Just my opinion, but I’ll never use CI stuff again. He blocked me on eBay from two different accounts. The reason? First I asked him why a carb kit I bought was missing a piece. The second time he blocked me, I asked if I could ship a head gasket to Canada.

The guy is a joke.


Sent from my iPhone using Tapatalk

[madmtnmotors]

Just my opinion, but I’ll never use CI stuff again. He blocked me on eBay from two different accounts. The reason? First I asked him why a carb kit I bought was missing a piece. The second time he blocked me, I asked if I could ship a head gasket to Canada.

Although I never had any issue with the pistons I received, based on your experience, and similar experiences of others, I would probably not use them again. I did try the C.I. carb float needles and bowl rubber seals (rubber tipped float needles) in my PD carbs. The rubber tips on the float needles and the rubber bowl gaskets turned to goo and started leaking within one week of exposure to ethanol laced pump gas. I sent C.I. an e-mail notifying them of the issue, not requesting any kind of refund mind you, just to make them aware of the substandard parts they were selling. Never received any kind of response. 

[kmb69]

.....
The good news is that CycleX responded to my reply, saying that they'll send me another set today. Cheers, Terry.

That is good news! I'm not surprised. My experience has been they are pretty stand-up kind of people. Typical small business - they have to bust their a$$ to eat!

[Ilja]

I have a cruzinimage 836cc piston set in my turbo bike.
Ran it for a few 1000km's, 12ish psi 120-130hp and Nm torque.
Still fine... they look absolutely spotless. I had them bored at 0.05mm clearance... so a little larger than normally.

BUT I have the RPM limiter at 9200rpm.... the turbo bike runs like a diesel car... strong from 5000-7500rpm.
If you are racing and you are constantly pushing 10.000rpm, you want to have forged pistons because they are more resistant against hairline crackings.

Only thing that suckes was that the cylinder bores were distorted at the bottom after boring, since they become so thin that they become hotter during machining and later contract more.
Offcourse I found out at home when measuring and had to go back to the machine shop, like always. 

[754]

That is strange, as they should hone the last few thou, and (hopefully) use a bore guage.
 Last summer I had a stock cylinder ball honed at the 11th hour trying to get to the reunion..
 And somewhere, before or after the honing, it appears the cylinder fell or something hit the sleeve,  and made a tight spot.
 About 1.5 by 1 inch.. of course couldn't find my diegrinder so I worked off the tight spot with sandpaper  took over an hour..
Check, check, and recheck... gets you an engine that works..

[Ilja]

Well, the OEM sleeves do become very thin with 836cc and they will be more prone to distorting and also distortion during running.
Especially when pushed hard or turbocharged. I have seen this after I removed the first set of Cruzini's of which I popped the ring-lands with pinging... strange glazed polished spots in the cylinder.

Re-sleeving to get some additional sleeve thickness would be best, you will see less blow-by.

But for a cafe-racer... meh don't bother.

On the 750 kawasaki turbo's the kit everyone gets is wiseco 810cc.. same issue with thin sleeves.
A lot of people now resleeve but then again a lot of people run 15-20psi boost with them which is a bit extreme.

[RottenRalph]

Ric, with these being street pistons with surely low crowns, my concern would be if you will be able to get the desired compression ratio and squish area with them.... not so sure

I will be using the kawa kz650 pistons kit, they are not flat but have a nice dome, so CR should be 11:1.
I have already installed them in the past, and I've known another couple of guys that did this modification, one here and one in the vintage racing community in Italy.
They match the standard cb750 pistons in the 2 dimensions that matter the most: pin diameter and height (compared to pin position): you just need some minor work on the valve pockets and they are good to go :-)

What make pistons did you go with in the end? Ive got a set of 65mm wiseco '4016' forged kz650 pistons and was hoping to use them! What mods did you make to yours to get them to clear the valves?

[MRieck]

I don't know of any issues with the Cruzinimage pistons. I installed a set of their 836cc pistons in my K1 4 or 5 years ago without any problems, I thought the quality was good, and I hammered that bike right up to when I swapped it for my RC51 last year, and I've stayed in contact with the the new owner, and he's loving it too. 

I bought some pistons from CycleX last month, and while they look OK, I wasn't happy with the way they packed them, throwing everything into a plastic bag, then throwing that into a box and sending it off is about as bad as a Customer Service can get. It might have been a one off, but I thought it was pretty pathetic.

CycleX piss poor packing by terry prendergast, on F

Must have missed this years ago.......I guess a couple of pieces of toilet paper between the pistons would have been appropriate.