I need to start looking for a new engine for my HPI Savage 25. Right now I have a mach 26 in it. My price range is around $150. Any suggestions? I was thinking on the OFNA FORCE .32 or Dynamite's .28 Big Red.

I've heard good things about both of those engines. I have heard that some Ofna/Picco engines require sealing because some of them leak. Dynamite engines seem pretty reliable in general but not the most powerful. Of those 2 you listed I'd go with the Dynamite Big Red first.

Other options:
Losi 454, about $200, but another engine with good reports from most users in regards to power and tuning.
Losi M.26SS, this is a very cheap engine at about $130. It's a sport engine so it is likely a lower performing RTR style engine.
RB .21 RTR, again a bit higher than your price, but looks to be a solid RTR replacement engine. Comes with a tuned pipe and header.
LRP Z.28R Spec 3, about $160, Very powerful for the price with a good rev range for a big block.
LRP ZR.30, about the same price as the Z.28R, lower rev range but more bottom end torque. Would likely want to gear a little higher for it.
LRP ZR.32, about $200, most powerful of their engines but the lowest revving so you would want to gear up a bit for it.

Any RTR style big block can be used such as Kyosho engines, Associated, HPI, and Ofna engines. RTR style engines are usually lower performing but easier to tune in general. Most any RTR engine can be found for a very cheap price on an Ebay chop shop, taken from an RTR truck that they part out for profit. Those types of engines would be the cheapest option, but not the most powerful. The AE 4.6 from the Monster GT is a good all around engine from what I hear, but not the fastest thing there is. I have a Kyosho KE .25 which performs pretty well and tunes nicely, but I've heard some of their engines are pure junk. The HPI Nitro Star F 4.6 is another decent one. My buddy has one in his Savage and likes it, it pulls wheelies on demand and is fairly easy to tune.

I'd recommend the LRP Z.28R Spec 3 for an 1/8 monster truck. It's price to performance ratio is excellent and it tunes very easily and is quite accepting to tuning and gearing changes. It's a bear to start when it's new but as it wears in it gets friendlier. I have one in my 14lb T Maxx and it pulls wheelies from a dead stop on command and from a rolling take off sometimes. The only down side to it is that it is quite fuel hungry. Mine drains a 150cc tank in about 7-10 minutes depending on how I drive it.

The best MT engin right now IMHO is the LRP ZR.30X, and you need to order the pullstart backplate separately(then put Rotostart or Spinstart cover on it.. Pullstarts suck on big blocks..) Amain has a %10 off deal for the rest of the month.

Failing that, scour ebay for a Losi 454, LRP Spec 3, or Dynamite Big Red .28. Those engines are all basically the same re performance. The ZR.30X is more explosive. My 454 winds out really, really nicely.. But the ZR.30X in my other LST2 is just.... scary. It hauls, and still has a good top-end. The great thing about it is the better carb makes it nicer to tune, and most importantly, it idles more stably. You don't need to blip the throttle so much to prevent it cutting out.. (Then again I ran my 454 the other day after sitting in the cellar for about eight months, and it ran perfectly...)

If you want to spend the money a Picco Boost .28 would also be a great engine. They're hard to find though, and cost more...

Is this the LRP you are referring to? Link

Thanks for the awesome detailed info. I'm highly considering the Big Red engine or LRP. Right now I have a mach 26. Should the Big Red or LRP 30 drop in easy or will I need to custom fit it?

That's it. You also need the pullstart backplate for it.

http://www.amain.com/rc-cars/lrp-zr....p38557/p291899

Then, on top of that, the Rotostart or Spinstart plate off whatever engine your truck came with.

Think I'm going to pick one up and covert my junk XXL-2. What pipe would you run if it were you?

Stock XXL/LST2 pipe. HD or whatever they call it... NOT the one from the Aftershock.

Assuming the header is the same off the XXL-2, you might be able to find something else. I have a JP-4 o my LRP ZR.30X in my LST2, and it's great. The stock LST2/XXL pipe was always very good on the Mach, LRP, 454, etc engines though.

Amain has a deal on %10 off everything in April I believe... BTW, if they still have them, the purple Odonnell medium plugs at Amain are my favorite non-turbo glow plug. Normally pretty cheap too.

You could also get the LRP ZR.30 non X with a pull start and swap it for a roto start. It comes with a backplate already then and it's the same price. I think it's slightly slower than the X version, though. Here

It's less a question of slower (though it may be..), and more about the quality of the carb, which is better on the X version.

Ah yes I see it now it is a different carb. The X version has a 7+1 port layout like the Z.28R and the non X is 5+1 as well so there's quite a difference there. I'd go with the X as well, it looks to be worth it over the non X. If it follows the formula of the Z.28R which has 7+1 ports it will be even more scary fast than that engine is Maybe that will go in my T Maxx when the Z.28 dies. I'd love to drive an MT with a ZR.30X in it some day.

Edit: Do you know if the roto start systems for big blocks are universal like the engine mounts are?

For the ZR.30X you need the backplate from the normal pullstart LRP 30 engine. Over that you can use a pullstart, Rotostart, or best of all, a Losi Spinstart backplate cover. It's amazing actually how reliable my Spinstart has been. I still have a second, unused one laying around I got with my second LST2 5+ years ago... It's lasted longer than most cordless drills would.

the LRP 30 and LRP 30X are both 5 port engines...the 30X does have a wider exhaust port so it will make slightly belter power on the high end and slightly less initial torque.... the 30X has a insulated carby, but IMO if your after a better carb then get a Nova or OS carb to use.....

On LRP's website it says they are a different amount of ports, though that could be an error on the listing. I don't know as I have never taken one apart of course.

So far my second pull start on my .28 is holding perfectly well, but I have been looking into getting a roto of some kind on there. It's a little harder finding a back plate cover that would work well on a T Maxx, unfortunately for me, given the chassis layout and the way the rear shock tower is made. It blocks off a good portion of the rear of the engine, so for that an offset cover would be needed. Those of you with a Savage have better options than I do. LRP makes a cover for the engines but I don't know how good it is, I know some of them are pure junk.