85cc monster Grave Digger

[John Parks]

Looks good!
I hope you bought lots of spare transmission shafts and diff output cups as your going to become an expert at changing them lol
Running the smaller mud truck tires should alleviate some of the stress on the drive train but with that engine I don’t think it’s going to matter
You putting the digger stickers on or just leaving it black?

I'm hoping it does ok, but I have my doubts. Smaller tires will definitely help, we will see. Haven't seen a need to upgrade to titanium trans shafts as I've seen a few snapping. From my readings, the factory ones are just as strong, but I am sending alx one to have him make and harden. Also though about ones made from stainless steel.

At this point, their isn't a bulletproof option so staying how it is. Has Taylor cups, and the bushings to help alleviate stress points, but also have some stock of that stuff for spares. Also, figured I'd show the cage needs cut in 2 spots, and one brace unscrewed.

 

[Seandonato73]

Stainless will be softer then regular steel mate.

 

[John Parks]

First run will be this weekend, hopefully tomorrow. Had it running already, gopro footage tomorrow hopefully. Have to rep the detroit performance stickers

 

[John Parks]

Unfortunately after about 11 minutes of runtime, clutch housing screws backed out and messed the case up a good bit, scarred the clutch also. It was fun though, have video I'll be posting, also developed and air leak, which made it run lean even richening it up.

 

[John Parks]

This was the first one before all hell broke loose

 

[spents]

This was the first one before all hell broke loose

is there meant to be a vid here john?

 

[John Parks]

is there meant to be a vid here john?

Whoops

 

[codeman11]

Sooo the 85CC is a bit much? lol that's just stupid my friend. Full throttle flips that thing like a rag doll ... why would you even bother with that size engine? Honest question ... even the Taylor 50 is too much from what I can tell, that 85 will probably break something new on every run! You can't even pin full throttle on that thing. It's a monster truck not an Ultra 4400

Sure sounds cool though I'll give you that. Didn't you already own one of these with a Taylor 50, or was that someone else on here I'm confusing you with

 

[John Parks]

That wasn't full power, had some engine issues, and a air leak. Basically some screws backed out and created havoc on everything. Why did I choose it you ask? Well it's a monster truck, it needs all the power . Plus I wanted something different most don't have. Keep in mind this is the first run, I'm going to taller gearing, and going to revisit the shocks as well to help handling. It's a bit stiffer than I like

50gt is a perfect balance of power in my opinion. It's won't destroy things as easy, but isn't garbage like the factory engine. Owned 3, one was a 50gt, another 71 Supreme, and this with the 85.

 

[Rep732]

Monster trucks by nature are overpowered and chaotic, nice job John.

 

[Seandonato73]

Heck, I thought it needed a 90..... very nice money bags aka John parks . Can't wait to see full power send it style!

 

[codeman11]

lol well, I mean I can't argue with the overpowered and chaotic standpoint. Fair point!

John, that wasn't full power even when it flipped it multiple times end to end?? Holy smokes. If you can swing it and try it, why not I guess right? I agree though the stock engine isn't what should be included with the kit, but I can also see why it is at the same time. I wonder if Primal will be pushed to further beef up the whole geartrain, especially since they sell larger than the 50GT on their website too.

That's mostly what would scare me away is snapping something all the time, but would be fun to try and tame all that power

 

[deathrawt]

If primal did upgrade the transmission and diffs to handle these overpowered engines we’d be snapping off driveshaft pins and wheel hex pins as they would be the next weakest link
Mind you I’d rather replace a wheel hex pin then a diff cup or tranny shaft lol

 

[John Parks]

Going to try and repair the case, got a time sert kit which seems better than a helicoil.

 

[deathrawt]

Hopefully it works out good, you have quite the mess there to get sorted out
really sucks that that happened to a brand new engine

 

[Seandonato73]

They are pretty good inserts, use them pretty frequently myself, machine shop used them and a full torque brand insert. The full torque was better for high load applications ie head bolts, main bolts etc but they cost 4x what the timeserts cost.

 

[John Parks]

I am pretty sure I can get it squared away and fixed to run easily. Alx is taking care of it regardless, so if I get this fixed I'll have a spare case atleast

 

[John Parks]

Some progress. Managed to get it back together, had a bit of an issue with the time cert not seating down all the way, so clearanced the clutch housing to go over them. Wasn't to impressed with that, but we will see how it holds. Engine is back in, waiting on a coil bracket and redid the fuel line so no more air leaks.

I also figured out vekta springs fit the v3 shocks, they are tight but fit perfect. Springs are tougher, and a bigger diameter and longer so hoping it helps

 

[Seandonato73]

I'd get ahold of time sert, the inserts should be flush to just a tad past flush. Likley the countersink cutter wasn't cut right.

 

[John Parks]

I'd get ahold of time sert, the inserts should be flush to just a tad past flush. Likley the countersink cutter wasn't cut right.

They didn't stop at the countersink though, about a 1/16th above the rim. Couldn't get them lower as the bit already expanded them