Engine repair and rebuild

[johnboybelfast]

Don't you just love getting old broken engines and makeing them shine agan got this hpi savage 3.5 on eBay in very bad shape slide carb locked the engine was completely seized and both bearings were completely seized thankfully iam a G and it's like new again 💪

Edited June 20, 2021 by johnboybelfast

[crazyfrog]

You’re not meant to take engines apart this far unless you’re buying new gaskets and o rings, HPI don’t supply engine o rings but use hard to get a hold of cheaply Japanese industrial standard (JIS) on the car itself so if you find the sizes please let the community know here.

[froggy8]

its fine, i have took it all apart and cleaned it then put it back together again with no problems.

 

the only thing i did was put engine sealant on the carb and backplate.

[johnboybelfast]

6 hours ago, crazyfrog said:

You’re not meant to take engines apart this far unless you’re buying new gaskets and o rings, HPI don’t supply engine o rings but use hard to get a hold of cheaply Japanese industrial standard (JIS) on the car itself so if you find the sizes please let the community know here.

IV been doing this for 20 years now never had to replace an o ring once luckily... And I believe it's a necessary part of maintenance after putting a fue gal of fuel through the block plus it's good to understand how things work and know how to replace engine internals 😁👌

[johnboybelfast]

IV been doing this for 20 years now never had to replace an o ring once luckily... And I believe it's a necessary part of maintenance after putting a fue gal of fuel through the block plus it's good to understand how things work and know how to replace engine internals 😁👌

[crazyfrog]

6 hours ago, froggy8 said:

its fine, i have took it all apart and cleaned it then put it back together again with no problems.

 

the only thing i did was put engine sealant on the carb and backplate.

Thats the thing you’re not meant to use sealant that’s what o rings are for and they do a better job.  Sealant can break down over time and get into spinning parts of the engine.

 

More so you’ve got a caked engine it’s more than likely you’ve had a leak.
 

5 minutes ago, johnboybelfast said:

IV been doing this for 20 years now never had to replace an o ring once luckily... And I believe it's a necessary part of maintenance after putting a fue gal of fuel through the block plus it's good to understand how things work and know how to replace engine internals 😁👌

You’ve not been using the internet as long double posting some forum moderators would give you a warning for that.

 

Nitro engines can usually still run with bad seals but they get difficult to keep running and users just assume nitros are like that or just state it’s fine for them. 

 

Most the time simply taking the carb off and putting it back it’s fine but when we’re talking about a full tear down on an old engine were every metal gasket and o ring is compromised it’s worth replacing the o rings and bearings for that matter.

[johnboybelfast]

A warning for posting the same thing twice??? It's a mistake IV never heard the like of it bro ...and people can do as they wish with there engines there's plenty of professional racers that post videos on YouTube of breaking down brand new reds engines etc there's no no rules around this so chill brother

[crazyfrog]

1 minute ago, johnboybelfast said:

A warning for posting the same thing twice??? It's a mistake IV never heard the like of it bro ...and people can do as they wish with there engines there's plenty of professional racers that post videos on YouTube of breaking down brand new reds engines etc there's no no rules around this so chill brother

Lol your attitudes so bad just bc you can’t use a forum.

I haven’t stated he can’t do it just that you’re not supposed to and the reason why.

 

You obviously don’t understand the difference between an old worn engine and a new one or you wouldn’t have brought up YouTube videos without a source or link.

[johnboybelfast]

What you mean I don't know how to use a forum ...yes iam new to this and don't know the DOS and don'ts but is it necessary to point out what I did. Is this forum not about posting stuff about RCs and sharing information and helping eachother? 

[Redback]

On 18/06/2021 at 23:41, johnboybelfast said:

Don't you just love getting old broken engines and makeing them shine agan got this hpi savage 3.5 on eBay in very bad shape slide carb locked the engine was completely seized and both bearings were completely seized thankfully iam a G and it's like new again 💪

Did a great job on the clean, smart move! Bet it will sound and run much better for it!

[johnboybelfast]

12 hours ago, Redback said:

Did a great job on the clean, smart move! Bet it will sound and run much better for it!

Bro its a beast no joke trying to upload a small vid but it's to big😅 thanks pal

[johnboybelfast]

12 hours ago, Redback said:

Did a great job on the clean, smart move! Bet it will sound and run much better for it!

Made it smaller it's sounds awesome can u tell me something there where 3 head shims on it so I just put them back on but iam running 20% nitro will it be better if a run no shims bro? 

[Stormbringer]

Seems to be running well 

[Nitroholic]

Your motor may or may not run better with the shims removed.

 

The shim removal will raise compression in the combustion chamber area, and reduce the squish clearance. Most likely you will get detonation. That can be quite damaging for an engine. Fewer shims will also make the 'sweet' area of tune narrower, and you may find it gets harder to hold a good tune. You might compensate a bit by using a cooler plug, but you may also find your motor just become very hard to find a stable tune with, and the motor spends most of its time choking on fuel, and not revving like it really ought. Fewer shims will give you more torque, but thats only a benefit if the motor runs cleanly.

 

If you do remove them...do it one at a time, not all 3 together. Remove one...run it, retune it, see how you go. Keep a close eye on temps, as while higher compression will give more grunt...it's also going to make things get hotter. It will give you the chance to assess how the changes are affecting it and whether its worth going any further, or whether you just want to put the shims back as they were.

 

If it was my engine, as it's not in the first flush of youth, I would leave the shims where they are. Run the motor and get used to it. If you haven;t fitted new piston, rod and liner, then the motor may not have wonderful pinch, and upping compression in the head will just bring more problems. And as it seems to run fine as it stands...... lt it be 🙂

 

That motor should run fine on 20% or 25% nitro,

[johnboybelfast]

That's some top notch advice thanks bro 👍