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Technical Forums => Milwaukee-Eight => Topic started by: pauly on November 04, 2023, 04:47:56 AM

Title: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 04, 2023, 04:47:56 AM
Hi all.
As with all subjects, the internet is awash with opinions on plastic in automotive applications. I had a bmw car that seemed to have more plastic than steel in the engine bay, and while it was young, everything was fine. As it aged though, the plastic components started falling apart.
So.... I have a lovely new 114 M8 with a plastic manifold, that we will be taking to some very warm (bastard hot) climates.
Is there any evidence of these plastic manifolds acting up in hot weather, or any other time for that matter?

Thanks
Pauly
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: Hossamania on November 04, 2023, 06:25:45 AM
Yes.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: Deye76 on November 04, 2023, 07:03:29 AM
Pauly, your car has water cooling.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: rigidthumper on November 04, 2023, 07:41:09 AM
Warpage of the plastic manifold can result in mild to severe intake leaks, causing issues. I'd recommend replacement after warranty period is over, or sooner if stage 2/3/4 is going to be done.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 04, 2023, 08:28:01 PM
My bike too 🤪

Quote from: Deye76 on November 04, 2023, 07:03:29 AMPauly, your car has water cooling.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 04, 2023, 08:29:11 PM
Man of many words 😂 Any details to share?

Thanks
Pauly

Quote from: Hossamania on November 04, 2023, 06:25:45 AMYes.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 04, 2023, 08:30:24 PM
Hi rigid thumper.
Thanks for that. Sounds like a plan, however I may struggle to wait that long.

Thanks
Pauly

Quote from: rigidthumper on November 04, 2023, 07:41:09 AMWarpage of the plastic manifold can result in mild to severe intake leaks, causing issues. I'd recommend replacement after warranty period is over, or sooner if stage 2/3/4 is going to be done.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: Hossamania on November 04, 2023, 09:55:27 PM
Quote from: pauly on November 04, 2023, 08:29:11 PMMan of many words 😂 Any details to share?

Thanks
Pauly

Quote from: Hossamania on November 04, 2023, 06:25:45 AMYes.

No.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: Hilly13 on November 04, 2023, 10:07:49 PM
Pauly, Lushy told me he has changed a heap of the manifolds on bikes sent to him for tuning as they were leaking, some much worse than others, owners didn't know, and that is the thing isn't it!
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 05, 2023, 02:19:10 AM
Hi Hilly,
Ok thanks. Think I will plan to replace it sooner rather than later as it can get pretty hot here in some areas of Australia. Would hate to have an issue in the middle of nowhere.

Thanks
Pauly

Quote from: Hilly13 on November 04, 2023, 10:07:49 PMPauly, Lushy told me he has changed a heap of the manifolds on bikes sent to him for tuning as they were leaking, some much worse than others, owners didn't know, and that is the thing isn't it!
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: Tail Ridr on November 05, 2023, 04:03:33 AM
Quote from: pauly on November 04, 2023, 08:28:01 PMMy bike too 🤪
Only on the exhaust side of your heads, still an air cooled engine

Quote from: Deye76 on November 04, 2023, 07:03:29 AMPauly, your car has water cooling.
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: FSG on November 05, 2023, 07:59:50 AM
Quote from: pauly on November 05, 2023, 02:19:10 AMWould hate to have an issue in the middle of nowhere.

which is where we are most of the time  :chop: 
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 05, 2023, 01:46:49 PM
Yes, I know.

Quote from: Tail Ridr on November 05, 2023, 04:03:33 AM
Quote from: pauly on November 04, 2023, 08:28:01 PMMy bike too 🤪
Only on the exhaust side of your heads, still an air cooled engine

Quote from: Deye76 on November 04, 2023, 07:03:29 AMPauly, your car has water cooling.

Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 08, 2023, 01:20:07 AM
I've ordered the se manifold, and associated seals and orings. Also got the dealer to confirm an ecm recalibration will not be required as its bone stock.
Thanks
Pauly

Quote from: Hilly13 on November 04, 2023, 10:07:49 PMPauly, Lushy told me he has changed a heap of the manifolds on bikes sent to him for tuning as they were leaking, some much worse than others, owners didn't know, and that is the thing isn't it!
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on November 26, 2023, 01:14:04 AM
Installed the se 55mm manifold today. Went without a hitch. No more worrying about high temps (common here in au) screwing with the plastic between my heads :-)

Quote from: pauly on November 08, 2023, 01:20:07 AMI've ordered the se manifold, and associated seals and orings. Also got the dealer to confirm an ecm recalibration will not be required as its bone stock.
Thanks
Pauly

Quote from: Hilly13 on November 04, 2023, 10:07:49 PMPauly, Lushy told me he has changed a heap of the manifolds on bikes sent to him for tuning as they were leaking, some much worse than others, owners didn't know, and that is the thing isn't it!
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: pauly on February 16, 2024, 03:28:30 PM
Update - I took the plastic manifold (which is perfect as it's only had a few weeks use) to the best Harley mechanic I know. I asked him to put it up on the wall, and when someone who comes in with a leaky M8, who is concerned about money ( we've all been there - hard times), he will give them the manifold no charge.

Thanks
Pauly
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: FSG on February 16, 2024, 04:23:51 PM
Quote from: pauly on November 26, 2023, 01:14:04 AMscrewing with the plastic between my heads :-)

maybee ears ???    :hyst:
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: roadkingdresser on February 19, 2024, 02:52:49 PM
So is it ok to use the harley o-rings on the S&S manifold?
Title: Re: M8 plastic intake manifolds. Any evidence of quality issues?
Post by: rigidthumper on February 19, 2024, 03:51:05 PM
Works fine