UPDATE ON ROBIN/SUBARU EX17 ENGINE

#1
Ok, so I figured out what the engine is, and I have the side cover taken off. I think it's saveable, there aren't any apparent cracks or damage on the inside of the engine, and the head looks good too. My only problem is this. I can go to harbor freight 3 miles from my house and pick up a predator for like 130$. OR, I can try to save this engine, which doesn't have any performance upgrades, but can take an absolute beating compared to the predator. But I really like this engine, but I don't want to pour a bunch of money into something I'm not 100% sure will work. It needs a new gasket set which is around 60$ on eBay. It needs a new carburetor which is around 20$ on eBay, it needs a new exhaust which is around 50$ on eBay, and needs a new starter pulley, flywheel, spark plug, cooling fan, camshaft bolt, air filter, all would come around 150$ more. So I don't think there's any reason I should try to keep working on the engine besides the fact that once its rebuilt it'll last longer on my go-kart than a predator would (hypothetically)
 
#2
I say, spend a lil more for the predator 224 max performance (223.2cc). You can thank me later, lol. The box says it makes 10.23 ft/lbs torq, i say its closer to 11 right outta the box. Mine probly pushes 14-14.5 now on 87 octane and turns 5500+ rpm with a .670 bored stock style carb and airbox. Very slightly modded, no crazy big cam or valve springs. it's a ridge runner, not a dragster.
the 224 has the clone flywheel taper, same rod journal as clones, and accepts the same cams and side cover as clones.
Predator 212 hemis takes a different flywheel and rod journal, but uses clone cams and side covers.
Predator 212 non hemis, use a different side cover and cams. Same rod as the pred 212 hemi, some say flywheel taper is not like the clone. But I have a pvl flywheel from a clone, on a 212 pred non hemi crank on my grandsons buggy, maybe going on 4 yrs now. It's never slipped or come loose, I don't use a flywheel key, I set ignition timing myself.
The 224 will pull more weight at less rpm then either pred 212, outta the box in stock form. After market parts, upgrades, cost the same, some jus don't interchange.
I took all 3 engines apart(new outta the box) to measure compression rarios.
Pred 212 non hemi was 7.7:1
Pred 212 hemi was 8.3:1
Pred 224 was 8.8:1

Hope this helps.
 
#3
https://www.eccarburetors.com/predator-224-oem-performance-engine-parts
Don't be afraid of that stock plastic geared cam. It's a lil bumpstick that has different specs then the 212's and 196 clones. Works real good at 5300 rpm max 10:1 CR with 1.3:1 stamp steel rockers, 22# valve springs, stock airbox, muffler, 19" tall rear tire and 155lb rider. Lol, I can't keep up with him. Im 50lbs heavier. But he's got that thing flying with that plastic cam, lol.
 

Bird Brain

Active Member
#4
Ok, so I figured out what the engine is, and I have the side cover taken off. I think it's saveable, there aren't any apparent cracks or damage on the inside of the engine, and the head looks good too. My only problem is this. I can go to harbor freight 3 miles from my house and pick up a predator for like 130$. OR, I can try to save this engine, which doesn't have any performance upgrades, but can take an absolute beating compared to the predator. But I really like this engine, but I don't want to pour a bunch of money into something I'm not 100% sure will work. It needs a new gasket set which is around 60$ on eBay. It needs a new carburetor which is around 20$ on eBay, it needs a new exhaust which is around 50$ on eBay, and needs a new starter pulley, flywheel, spark plug, cooling fan, camshaft bolt, air filter, all would come around 150$ more. So I don't think there's any reason I should try to keep working on the engine besides the fact that once its rebuilt it'll last longer on my go-kart than a predator would (hypothetically)
The Robin is a pretty neat design. If money was not a factor and its condition is fair enough to rebuild i personally would. Not sure why, perhaps because pushrods travel in and up down motion and a chain travels in a one direction with a continual load driving the valves not sure, but chain driven valve trains always seem to have a longer unproblematic service life ive noticed. Might be something that gives you more run life after a build. But true a brand new engine out of a box is probrably easiest and a more economical route.
 
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