Engine value question...

[tazzman68]

Hey all, I have been wanting to do an engine mod, but don't want to try it with the only motor I have for my savvy. I have found an HPI 25 on CL that needs a piston and sleeve. I asked the guy what he wanted for it, and he came back with "make me an offer" so what should I offer him?

 

[Larsenracing]

If the engine needs a new piston and sleeve it will cost you about $40-50 to get them. I wouldn't give him more then $35 shipped for the block, head, crank, back plate, & bearings.

The s-25 is an old motor and didnt make near as much power as the current stuff. You can get a new Axial .28 Spec 1S for around $109 maybe cheaper from the Bay.

 

[nickmind]

I agree 100% with larsen. In fact I would tell the guy just what larsen said. Seriously Axial engines are very cheap, and will put out about 2x more power then the s-25. $20 to $30 sounds about right.

 

[Larsenracing]

I'm not sure if its 2X more power but it will be some. Personally I will buy no more axials but I do run 2 of the Spec 1S motors and they have been decent motors. I have one thats slightly modded and it rips around pretty good. Both have more than 5-6 gallons on them.

If your going to have more than $70 into a used motor and want to learn P&P I would but a new mill say the Axial. You are going to want to get it at least threw break in. This will give you some lines in the sleeve to work by. This will help in a newbie P&P Job. I defiantly like them there as you know what angles you can Port to. Just some in site.

 

[nickmind]

I'm not sure if its 2X more power but it will be some. Personally I will buy no more axials but I do run 2 of the Spec 1S motors and they have been decent motors. I have one thats slightly modded and it rips around pretty good. Both have more than 5-6 gallons on them.

If your going to have more than $70 into a used motor and want to learn P&P I would but a new mill say the Axial. You are going to want to get it at least threw break in. This will give you some lines in the sleeve to work by. This will help in a newbie P&P Job. I defiantly like them there as you know what angles you can Port to. Just some in site.

Sorry you're right, 2x would be extreme. I meant to say about (need to still wake up). But, it would be close to that on the torque side, and close to 30% to 40% faster.

 

[Dreadnaught]

but for an engine to learn how to p&p on, an old s25 engine would be good.

 

[BIGDAN89]

if you mod the s25 right it screams hahah i have a s25 with a lot of work and it hauls. special tuned for 30%race but umm 35 sounds right if it needs a new internals

 

[Larsenracing]

I agree the S25 has great potential especially when Extrema modding is done this includes adjusting the timing and modding the piston skirt. But for a beginner your not going to go that extrema especially right away. Just watch so you don't get to much $$ tied up into it as you can get other mills which have more power stock and have the same potential of the same percentage of power gain for roughly the same money and everything is new on them.

 

[tazzman68]

Thanks everyone, I offered him $20 as a starting point. Hopefully he accepts.
So your saying I should get the new piston and sleeve and assemble and run it for a bit before I mod it? Sounds reasonable. I am no stranger to P&P, but this will be the first time on this small of a scale, and I do consider myself a bit of an expert with a Dremel. I have read the tutorial and am confident that I can build a screamer. I just won't sacrifice my only running big block to the power gods just yet.

 

[Larsenracing]

Yes, I would run it some at least breaking it in. This puts flow marks on the sleeve. These are much different than 1:1 scale motors because there is different cuts to make to increase flow unlike the porting and polishing of a 1:1 scale engine.

The good think you have is the skills and knowledge of doing this and the know how to use a dermal along with the know how to get things polished up. Good luck to you bud and make sure to do a step by step process to it.

I am going to see if there is any way we can add a section to the engine section that this very thread is in just for engine modding.