Big Block Engine Shortage?

SquidBonez

Member
Messages
311
Reaction score
9
Location
New Jersey, USA
Anybody notice that it's near impossible to find any store selling the big block engines (420,440, etc)? Every Harbor Freight in literally a 40 mile radius from my house is out of stock on the 420ccs, and even Amazon is out of stock on the Duromax 440ccs. I found a few lesser-known brands like xtremepowerUS on Amazon that have 420s and are in-stock, but I don't trust them. Anybody else having this issue?
 

karl

Well-known member
Messages
1,914
Reaction score
89
Location
North east Ohio
Think your onto something. I'm not in the market, but I checked HF and i'd have to drive up to New York to get a 420cc.

Even carroll stream has 2-3 week wait. Probably a supplier of a certain big block parts or two experienced
current world event difficulties at some point.
 

Karts of Kaos

the many mowers guy
Messages
946
Reaction score
67
Location
Wisconsin
maybe it has something to do with more expensive aluminum? i thought i saw something like that on the new recently. predators are up to $150 near me aswell
 

SquidBonez

Member
Messages
311
Reaction score
9
Location
New Jersey, USA
Think your onto something. I'm not in the market, but I checked HF and i'd have to drive up to New York to get a 420cc.

Even carroll stream has 2-3 week wait. Probably a supplier of a certain big block parts or two experienced
current world event difficulties at some point.
Never heard of Carroll Stream until now. Sure enough they do sell a 420cc engine. Do you have any experience with them? Are they good engines? Do all the Predator 420 bolt-ons work with them?
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Anybody notice that it's near impossible to find any store selling the big block engines (420,440, etc)? Every Harbor Freight in literally a 40 mile radius from my house is out of stock on the 420ccs, and even Amazon is out of stock on the Duromax 440ccs. I found a few lesser-known brands like xtremepowerUS on Amazon that have 420s and are in-stock, but I don't trust them. Anybody else having this issue?
A buddy of mine looking to replace his worn out 420cc had hell trying to find one in north texas anywhere too.. he finally found one online..


keep in mind they are also generators..
 

SquidBonez

Member
Messages
311
Reaction score
9
Location
New Jersey, USA
Yesterday I went to a Harbor Freight near my work after I got off. Online they said they had one. Showed up and the guy said somebody had just bought it 3 hours earlier. Made a comment about how these things are just flying off the shelves and he mentioned a lot of people have been coming in to put them on go-karts...LOL.

Luckily today I managed to get one at the HF near my house. I called ahead to make sure they had some in stock. Lady on the phone said - without skipping a beat - "we only have one in stock and no I can't hold it for you". I never driven to HF that fast before LOL.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
If you could even get one of your choice................They do come in both hemi and non-hemi versions, 60340 and 60349 or vice versa, right?
That being chosen if you could do so, why does the standard EPA carb version have 19.8 ft./lbs. @ 2500 rpm torque, while the EPA/CARB emissions version only have 18.4 ft./lbs. @ 2500 rpm torque, and does that apply equally to both the hemi and non-hemi versions?
Can a simple modification of something on the emissions version (voids warranty of course) raise its torque by 1.4 ft./lbs.?
EDIT: Random question............Why is the emissions version 3 lbs. lighter than the standard version?
 
Last edited:

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
If you could even get one of your choice................They do come in both hemi and non-hemi versions, 60340 and 60349 or vice versa, right?
That being chosen if you could do so, why does the standard EPA carb version have 19.8 ft./lbs. @ 2500 rpm torque, while the EPA/CARB emissions version only have 18.4 ft./lbs. @ 2500 rpm torque, and does that apply equally to both the hemi and non-hemi versions?
Can a simple modification of something on the emissions version (voids warranty of course) raise its torque by 1.4 ft./lbs.?
EDIT: Random question............Why is the emissions version 3 lbs. lighter than the standard version?
I doubt those ratings are very accurate, but with my experience its going to come down to the jetting in the carb itself for the torque. Also, one of those is Cali emissions compliant and the other 50 state emissions compliant, but I cant tell you more about it on mine because that stock crap was the first to go.. maybe it makes a difference in weight with internals of the cat/exhaust? Would def be different between emissions standards.. Where else would the extra weight be hiding? Just my .02.. which is worth exactly that here.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
My first thought is that the main jet would pretty much have to be different on the emissions version to lose 1.4 ft./lbs. of torque. Close examination of the available pictures doesn't show any extra tubing to feed vapors back into the carb. Can't tell if the contents of the muffler is any different.
I can only think of the timing being advanced ahead of the normal stock setting for a more complete combustion of the fuel/air mixture. Thinking that timing advance combined with less fuel from a smaller main jet might lose 1.4 ft./lbs. without them having to claim a loss of 1/2 a horsepower or so. Very simple fix on that, just a bigger jet, leave timing advance as is.
I have 7.2 degrees advance and a .036 jet on my current 212, my fix of the emissions version 420 might make sense. Anybody have any other ideas? Supply shortage could force folks into settling for the emissions version engine, with a hope to fix it.
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
My first thought is that the main jet would pretty much have to be different on the emissions version to lose 1.4 ft./lbs. of torque. Close examination of the available pictures doesn't show any extra tubing to feed vapors back into the carb. Can't tell if the contents of the muffler is any different.
I can only think of the timing being advanced ahead of the normal stock setting for a more complete combustion of the fuel/air mixture. Thinking that timing advance combined with less fuel from a smaller main jet might lose 1.4 ft./lbs. without them having to claim a loss of 1/2 a horsepower or so. Very simple fix on that, just a bigger jet, leave timing advance as is.
I have 7.2 degrees advance and a .036 jet on my current 212, my fix of the emissions version 420 might make sense. Anybody have any other ideas? Supply shortage could force folks into settling for the emissions version engine, with a hope to fix it.
on my 440 I had to go about 6-7 sizes up from stock jet before it woke up...
 

SquidBonez

Member
Messages
311
Reaction score
9
Location
New Jersey, USA
If you could even get one of your choice................They do come in both hemi and non-hemi versions, 60340 and 60349 or vice versa, right?
That being chosen if you could do so, why does the standard EPA carb version have 19.8 ft./lbs. @ 2500 rpm torque, while the EPA/CARB emissions version only have 18.4 ft./lbs. @ 2500 rpm torque, and does that apply equally to both the hemi and non-hemi versions?
Can a simple modification of something on the emissions version (voids warranty of course) raise its torque by 1.4 ft./lbs.?
EDIT: Random question............Why is the emissions version 3 lbs. lighter than the standard version?
At my store they stock hemi versions luckily. If you wanted to you could convert a hemi to non-hemi and vice versa. Only difference is the head/piston/pushrods. Hemis have flat pistons and non-hemis have dished. Hemis have longer pushrods as well. Also hemis have bigger valves I believe. That and a better combustion chamber. That's where they get the extra torque I assume. Only downside with the hemi is that it is predator-specific parts for the head. The non-hemi is a true GX390 clone in the sense that anything that fits a 390 head will work on the 420. But on the plus side the hemi head is slightly better and I believe have stronger rockers. Easier to set the valve lash on too since the rockers don't walk side to side.
 

madprofessor

"Loose Cannon Creations"
Messages
1,314
Reaction score
182
Location
Jacksonville, Florida
Excellent to hear on the hemi version, definitely would choose it for the flattop piston like the 212's I've used. Otherwise I'd be retrofitting a flattop into a non-hemi. If I do a 420 I want the only extra money dumped into it to be for intake and exhaust mods and upgraded jetting.
 
Last edited:

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Excellent to hear on the hemi version, definitely would choose it for the flattop piston like the 212's I've used. Otherwise I'd be retrofitting a flattop into a non-hemi. If I do a 420 I want the only extra money dumped into it to be for intake and exhaust mods and upgraded jetting.
honestly dont even spend the money on jets. buy a weld tip cleaner set and run through the jets one size at a time and see how it runs doing plu checks.

Also I didnt think there was a diff in HP with non hemi? Does anyone have more info on this??
 

SquidBonez

Member
Messages
311
Reaction score
9
Location
New Jersey, USA
honestly dont even spend the money on jets. buy a weld tip cleaner set and run through the jets one size at a time and see how it runs doing plu checks.

Also I didnt think there was a diff in HP with non hemi? Does anyone have more info on this??
Both are rated for 13 horsepower, but the hemi has slightly more torque. You can see on the side of the box. Madprofessor posted the exact numbers.
 

joejoeguns

ya thats my bike
Messages
24
Reaction score
0
Location
n.w. indiana
I just bought a Duromax 13hp frome Home Depot for 360 bucks delivered to my house. Made in U.S.A. with electric start. Still a clone of the gx390 but don't know if any of the same hop up parts work.
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
I just bought a Duromax 13hp frome HomeDepot for 360 bucks delivered to my house. Made in U.S.A. with electric start. Still a clone of the gx390 but don't know if any of the same hop up parts work.
my buddy has the same and we are finding out some of the 420 parts dont fit. I believe the duro 13hp has a diff head, and the 420 header doesn't bolt up. I am thinking its more along the lines of a 301cc or gx340 style head. One thing I did learn about the duro motors is they are basically frankenstein motors, they have done some odd things with the building but my 440 is strong as f*** after jetting..

And my 440 is rated that way because its got a longer stroke and overbored.. higher compression.. thus rated at 18hp and pushing more like 20 now over the predator 420 rated at 13-16hp stock. I am still digging up info on the 13hp duro in my spare time to help a friend.

If yours wont run with the choke completely off you need to drill up your main jet.
 

miniblazinbmx

Member
Messages
84
Reaction score
11
Location
Texas
Specs on that Duromax say 21 ft./lbs. of torque. Sounds good to me, Predator's only claiming 19.8 ft./lbs. on the standard emissions 13 hp. version, which is 1.4 more than the EPA/Carb version of 18.4
Their website states 26ft lbs for the 440cc.. either way anything over 10hp is a lot for any of our karts considering none are really built with correct tubing for crashes lol
 
Top