New/Used HPI RS4 3 And Lots of Qs

Looks like a pretty good deal. You may have to loosen the top plate to get the pack out. But if it's good, I'd just leave it be. The connector on the switch is probably were the battery plugs in. The little circuit board with the red light is probably a fail safe. As far as cleaning the rust up, use a bit of wd40 on a rag and wipe the metal parts off. Check all the bearings to make sure they spin smoothly. If the car rolls smooth, your probably alright there. As far as the engines go, run whatever one has the most compression. Don't be fooled into thinking one has more compression than the other because one is harder to spin. Used engines could always be gummed up with old fuel. I'd strip both of them one at a time, clean them thoroughly with fresh fuel and seal them up. Then check for compression. They may both be fine. You have a lot to work with there. If one of those engines run well, you got a stealin' deal. Get your electronics up and working properly first, then move on to the engine. I look forward to seeing your progress. Keep the questions coming and good luck.

the battery pack looks to be held in place with a couple rows of double sided Foam Tape.... super strong stuff.. as matt said, if it seems to say put, leave it be.


as far as the engines, the one with HPI on the side of it looks be be the first of the "nitro star" series. my typically it's a .15 engine.

What kind of engines does this car go with? I may just get another engine if these 2 are no good but I want somethin nice and powerful. Would that red/black wire off the switch be a charging line? Because I can't find where or howd id charge that pack..

Thanks for the great input thus far and will keep posted with more pictures as I tinker on her

HPI-Killer said:

What kind of engines does this car go with? I may just get another engine if these 2 are no good but I want somethin nice and powerful. Would that red/black wire off the switch be a charging line? Because I can't find where or howd id charge that pack..

Thanks for the great input thus far and will keep posted with more pictures as I tinker on her

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Any "small block" engine should work with that chassis. I know HPI is using the new G .15 Series engine with their new drift kits. Nova Rossi makes HPIs engines, so they are nice strong engines, and will last a while with good care. that's for dang sure. I'm still using the engine that came in my Evo 3, and that was a few years ago, and it still runs strong w/ good compression.

That plug may be a charge lead. If there's a connection going to the switch already, it probably is.

Metalhead Matt said:

Don't be fooled into thinking one has more compression than the other because one is harder to spin. Used engines could always be gummed up with old fuel. I'd strip both of them one at a time, clean them thoroughly with fresh fuel and seal them up. Then check for compression. They may both be fine.

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Now when I start on the engine tear down does that mean the ENTIRE thing? gears clutch bell and all that sort on the front on the engine along with the head pistons and such inside? Oo I'm scared, never tore down an engine before! should be fun PS- These engines reak of old fuel bad

Metalhead Matt said:

That plug may be a charge lead. If there's a connection going to the switch already, it probably is.

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Yeah theres 2 wires, one goes from the switch inside the chasis somewhere and the other hangs like described, never seen a charge head like that before, it didnt come with any chargers so I need to buy myself one for that I reckon

HPI-Killer said:

Now when I start on the engine tear down does that mean the ENTIRE thing? gears clutch bell and all that sort on the front on the engine along with the head pistons and such inside? Oo I'm scared, never tore down an engine before! should be fun PS- These engines reak of old fuel bad



Yeah theres 2 wires, one goes from the switch inside the chasis somewhere and the other hangs like described, never seen a charge head like that before, it didnt come with any chargers so I need to buy myself one for that I reckon

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Yes, you'll need to pull the clutch bell off, and the bearings/spacers, flywheel and all of those goodies off of the car. and when you pull the head off and the cylinder out, make sure to use DA to wipe everything down. and if i were you i'd use a small amount of GOOD fuel to lube everything when you put it back together.

+1. I'd at least take off the clutch, head, carb and back plate. Then soak everything in fresh fuel over night. Then rotate the flywheel and rinse out the inside of the engine real good. Same with the carb. Just be sure and take notes/pictures of how everything goes back together. The orientation of the carb and back plate. That way once you apply sealer, you get everything where it goes the first time. Sometimes if the carb is a little twisted in it's hole, the linkage won't line up or it will bind. Just put everything back together the way it came apart and you'll be good to go. And don't be scared. Just take your time and pay attention. It's pretty simple.

Metalhead Matt said:

It's pretty simple.

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It's really simple... it took me 30 mins to have my Nitro Star .15 torn apart in pieces on the table and back together again when i had to replace a broken crankshaft.

Here are some good links to help you out.

http://www.hpiracing.com/walkthrough-engrebuild/

https://www.rcnitrotalk.com/forum/showpost.php?p=726317&postcount=6

Ok I have cleaned one of the 2 engines and now need to see how I do a compression test and determine which engine is better? Input please.


Thanks

HPI-Killer said:

Ok I have cleaned one of the 2 engines and now need to see how I do a compression test and determine which engine is better? Input please.


Thanks

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The "good ole' boy" method is take one finger from one hand and trying to turn the the fly wheel by that one finger, if it is tight. if it is "hard" to turn the engine has good compression, if it is super easy to turn and it just flips over it's a bad engine. you might want to look into a new sleeve/piston combo or an engine.

the official way is to get a compression tester, find the compression, and do the same thing and see what the compression is, and how long it holds it....


but the first method is sufficient for the most, personally i'd never look into a compression tester.

mjneid said:

The "good ole' boy" method is take one finger from one hand and trying to turn the the fly wheel by that one finger, if it is tight. if it is "hard" to turn the engine has good compression, if it is super easy to turn and it just flips over it's a bad engine. you might want to look into a new sleeve/piston combo or an engine.

the official way is to get a compression tester, find the compression, and do the same thing and see what the compression is, and how long it holds it....


but the first method is sufficient for the most, personally i'd never look into a compression tester.

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Ok started on my 2nd engine, I think the v15 is bad but I can't get the darn flywheel off to clean it better. Do I want to do this compression test with or without the glow plug in?

HPI-Killer said:

Ok started on my 2nd engine, I think the v15 is bad but I can't get the darn flywheel off to clean it better. Do I want to do this compression test with or without the glow plug in?

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you have to have the GP in the engine. w/o the GP the engine will not build compression.

Anyone know how I can get the flywheel off? I can't even get the nut to turn in front of the flywheel.. GAH! Even if it is not needed, the piston and sleeve has a very faint line scratch running up and down, barely feelable to my fingernail. Should I proceed or is this no good? I don't even know how to ID the engines to replace parts if I needed to.

HPI-Killer said:

Anyone know how I can get the flywheel off? I can't even get the nut to turn in front of the flywheel.. GAH!

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If it is set up like the nitro start .15 you have to take that nut off of the crankshaft, w/ the correct tools, and the fly wheel should just pop off.

mjneid said:

If it is set up like the nitro start .15 you have to take that nut off of the crankshaft, w/ the correct tools, and the fly wheel should just pop off.

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Is this a special hobbiest tool or a simple socket removal?

HPI-Killer said:

Is this a special hobbiest tool or a simple socket removal?

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mine just twisted off with a standard socket and ratchet.

Well I am completed with my 2 engine tear down, after the v15 was done I put her back together and sealed it up and held almost no compression, damn shame because I had fun cleaning it all up. As far as the second engine, no pics cause I was half asleep but had almost no wear n tear at all but was full of laundry detergent so I'm glad I tore it down. Tore down, cleaned with nitro and WD-40, sealed and rebuilt & was happy that it held compression cause I didnt want to buy a new engine. Thanks for all the input and will keep this thread posted as I get her back together.




One question I do have is there anything on the blown engine that I can save & re-use?

HPI-Killer said:

One question I do have is there anything on the blown engine that I can save & re-use?

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the make awesome Christmas Ornaments

clutch bell including bearing, shoes, gears, carb if she doesn't leak... have you tried looking for a sleeve/piston for the engine....