reliability of a 16mm stroker?

[wsuwrhr]

I don't remember exactly, maybe $7 a bolt. I believe the head was too big and had to be trimmed down a bit. It would have worked for the cylinder, but not for the cases.

Doesn't matter anyways, we have already solved the problem.

Brian

Brian, since you are building the top of the line stuff why not use ARP 300 stainless studs and bolts. Seems to me if someone is paying that much for an engine they should pay for the best parts to hold it together? I haven't bought ARP in awhile and I know they are not cheap. What was the price difference?

 

[Waternut]

Unfortunately.....

That has been a problem, in our opinion, stainless is not the answer and we don't recommend using them either.

Unless it is a high-end bolt like ARP, stainless as a critical fastener is just not worth a damn, either in elasticity or in it's service life by galling. That is exactly why you won't find any stainless hardware on our motors except for the PV attachment hardware.

We have tried to find a suitable, cost-effective alternative, as sh itty as it sounds, we decided having a rusted bolt is better than having a stainless bolt failure.

We weren't able to find anything, so now we are having the steel bolts stripped and zinc plated.

Brian

I'm sorry to call you out but that just sounds like unsubstantiated talk to me. Pretty much every person on this board runs stainless bolts in their engines and if the hardware was a problem why aren't we hearing about bolt failures every other day? The only stainless hardware I've broken were the little 6mm bolts that I twisted the heads off and I've over torqued the piss out of some head pipe bolts without problems.

In addition, every plane I've worked with uses some form or stainless or titanium fastener in critical locations. This includes the F-15 which uses stainless hardware on the wing attach points. I understand titanium is too expensive for jetski applications but how is stainless not the answer? Sure steel and aluminum don't react well together because they'll induce corrosion but "chance of corrosion" sure beats "guaranteed corrosion" in my book.

 

[DAG]

Almost laughable threads sometimes, the people with bad "experience" ruin it for the other guys looking to step up to a bigger motor, or worse, get talked into the stock stroke/90MM big-bore deal thinking it is a good idea.

Whys the stock stroke/90MM big bore a bad idea?

 

[egbrig]

I've been amazed at listening to people give expert advice on what works and what breaks only to see them work on their own boats and realize that they don't have a mechanical clue. There's a group that claims to strip driveshafts all the time with basically stock engine's, found out they don't know how to align a driveshaft. But they kept swearing its the parts fault.

 

[wsuwrhr]

Unsubstantiated talk? Unbelieveable.

If you put a stainless bolt anywhere on your jetski and it breaks, you can bitch at yourself and your friends about the "cheap stainless bolt" all you want. The simple fact is, any stainless bolt, other than a top grade stainless, isn't worth a sh it. You can take that to the bank.

DASA and SB Products, for the most part, in good faith, have to carry our products for it's lifespan. Any possible foreseable failure or damage needs to be considered no matter how slight.

You break or gall up a stainless bolt on your jetski THAT WE SUPPLIED YOU, I WILL GUARANTEE you will come on here and talk bad about it and will likely tell everyone you know about the failure.

I don't mind hearing about rusted bolts, although everytime it has turned into the same conversation over again. Even in a thread about "broken" stroker cranks.....There has yet to be a thread on here about a fastener failure from DASA or SB Products supplied hardware and there likely won't be.

Your F-16 is paid for by the government(taxpayers) which is you and me, so no doubt they will use the best of the best, sir.

I am sure you have seen the price tag that is attached to them as well.....

AGAIN.....

Doesn't matter anyway, as I have stated TWICE, in this very thread, that the problem has been since resolved.

Brian

I'm sorry to call you out but that just sounds like unsubstantiated talk to me. Pretty much every person on this board runs stainless bolts in their engines and if the hardware was a problem why aren't we hearing about bolt failures every other day? The only stainless hardware I've broken were the little 6mm bolts that I twisted the heads off and I've over torqued the piss out of some head pipe bolts without problems.

In addition, every plane I've worked with uses some form or stainless or titanium fastener in critical locations. This includes the F-15 which uses stainless hardware on the wing attach points. I understand titanium is too expensive for jetski applications but how is stainless not the answer? Sure steel and aluminum don't react well together because they'll induce corrosion but "chance of corrosion" sure beats "guaranteed corrosion" in my book.

 

[wsuwrhr]

Whys the stock stroke/90MM big bore a bad idea?

I have covered this subject 20 times already in the other threads.

Buy one for yourself and compare it to an EQUIVALENT DISPLACEMENT 800-900cc engine correctly done with a stroker crank and big bore, with "only" 85 MM style pistons and please report back with your results.

I doubt you will think "stock stroke 90MM big bore engine" is still a good idea.

Brian

 

[#ZERO]

What do you think happened here?

I'd place my bets on the crank not being trued properly causing a stress fracture on the center rod pin.

 

[DAG]

Buy one for yourself and compare it to an EQUIVALENT DISPLACEMENT 800-900cc engine correctly done with a stroker crank and big bore, with "only" 85 MM style pistons and please report back with your results.

I doubt you will think "stock stroke 90MM big bore engine" is still a good idea.

Brian

Should performance/dollar also be a factor when considering Reliability and Upkeep vs Stoker

 

[kevbo]

Why dont you just seal off the bolts? A stainless or titanium bolt in an aluminum part will corrode faster than anything if it gets wet.

 

[wsuwrhr]

Should performance/dollar also be a factor when considering Reliability and Upkeep vs Stoker

What dude?

Whatever man, buy whatever you want.

I'm not bothering with silly comments or questions. Sorry man. I have covered my opinion on the deal plenty enough, everyone is entitled to their own ideas.

My .02, if you want cheap, stick with stock. Everything else costs money in the long run.

 

[wsuwrhr]

Why dont you just seal off the bolts? A stainless or titanium bolt in an aluminum part will corrode faster than anything if it gets wet.

Thought about that for the case, since that would be easy, the cylinder just wouldn't look that good though.

The bolts are zinc plated now, so minor problem solved.

Brian

 

[wsuwrhr]

How about we get back on track and talk about crankshafts and fire up as many other threads about things unrelated to cranks?

I'll be happy to debate those subjects if it is welcome.

Brian

 

[luker]

once again shouldnt have brought it up, if the problem has been resolved its been resolved , like i said the engine is top notch and no complaints what so ever about performance and workmanship!

 

[wsuwrhr]

once again shouldnt have brought it up, if the problem has been resolved its been resolved , like i said the engine is top notch and no complaints what so ever about performance and workmanship!

Thank you sir. From both of us.

Neither DASA or SB Products has anything to hide, we are both proud of and take great pride in what we do, and I don't mind answering questions or addressing concerns of custumers or future custumers or even neither of those.

This thread just wasn't the place, it is about cranks and stroker crank "reliabilty" and maintainance of said cranks to be exact.

Brian

 

[norcal ex]

I love how a large majority of people here "debating" against engine builders such as dasa and brian have no clue about high performance motors, never has built a high performance motor, will never be able to afford a high performance motor, will never have the skills to use a high performance motor.

Have a merry christmas everyone :newangel:

 

[McDog]

how ofter do you have to pull the 16mm Dasa stokers apart for inspections/rebuilds if you had the dasa cases and cylinders and their crank?

This is the original post. I think the answer is ask the person who built your motor what they recommend and that stroker motors wear out faster than standard stroke motors because the pistons move faster in the cylinder.

This is how it was explained to me by an engine builder. Would you agree?

 

[WaveDemon]

This is the original post. I think the answer is ask the person who built your motor what they recommend and that stroker motors wear out faster than standard stroke motors because the pistons move faster in the cylinder.

This is how it was explained to me by an engine builder. Would you agree?

depending on the set up, they also have sharper connecting rod angles and shorter piston skirts. all of that adds up to shorter piston life.

 

[norcal ex]

depending on the set up, they also have sharper connecting rod angles and shorter piston skirts. all of that adds up to shorter piston life.

both of those issues are resolved by using longer rods

 

[wsuwrhr]

Original post got deleted....crap

This is true on the surface and you are correct.

But PTS is affected by other things as well, stroke and rod length also play a part in dwell(which is also very important) which also effects PTS, or namely piston acceleration. Which in my opinion, is what really kills pistons.

Imagine an object slinging into space at a high velocity and IMMEDIATELY having to change direction and go back the other direction only to repeat this a million times over. Not a very happy existence.

Rod length is a debatable engine characteristic and it does change engine behavior.

...and again, idealy a larger more-powerful motor will spend less time at or near WOT than a smaller less-powerful motor. The "work" done will generally be done at a lower RPM for a smaller period of time.

This also equates to better fuel economy too, try convincing someone of this until they see it with their own eyes.

Hey give me a break today, it is Xmas eve and I am working and trying to answer questions here and Dan isn't even here, which in itself is a rarity.

Brian

....and that stroker motors wear out faster than standard stroke motors because the pistons move faster in the cylinder.

This is how it was explained to me by an engine builder. Would you agree?

 

[wsuwrhr]

both of those issues are resolved by using longer rods

exactly