big engine problems

[kmiller]

Well I'm new to 1/5 scale cars and bought a used Fg Marder 4wd, ran strong for the 3 short times i used it. I was running the other day and I thought I ran to low on fuel, car did not want to stay running... I filled with gas and supper hard to start and once started it would run wide open for a few seconds and stall. I pulled the engine to take a better look and found the head cracked from the head bolt under the exhaust port and the small exhaust port brace. It is a kingmotor and I was told it was a zenoah (my fault)... It has a DDM Dominator Chrome Pipe (unless thats a knock off as well? The way the pipe mounts is solid, is that why the head cracked? If it was a zenoah would it have cracked as well?? What engine should i replace it with?

See my car here...
https://www.largescaleforums.com/showthread.php?t=16875

 

[dscjester]

Was it a 2 bolt cylinder head? It could be a combination between the 2 bolt cylinder (weak) a solid pipe and of course heat. I run the that same FG Dom pipe with no problems on a 2 bolt head. You may have taken a hard roll hit the pipe, thus breaking the head.

With that said, for a new motor, I would check out DDM, and look into the G290. It's a great all around motor and has the 4 bolt cylinder head making it stronger. Also it is a great platform to upgrade on later if you want after you get more familiar with these 2 strokers.

 

[voo2doo]

Heads crack as a result of a rigid pipe.I have seen a few on here with head cracks.
If you have a pipe with no 'give' and rear end land the truck it will eventually crack the head by the bolts.
Have a word with Jackobyte,I think he has done two!
J

 

[renbar]

ive done one when i had the runaway and hit wagons car with the marder it cracked the head at the exhaust port but i never noticed for a few weeks until bang it let go bigtime when i took the head off it fell apart lol

 

[jackobyte]

Yep a hit on the pipe would cause that, i went through 2 KM head kits with bad rear landings....mine was on a KM Baja though with the rigid dom clone but your rigid pipe would also crack the head bolt as theres no flex to take some of the impact...i'd also expect a Zen or CY to go the same way if enough pressure was put on the head bolts, a 4 bolt would be stronger...

 

[kmiller]

Yep a hit on the pipe would cause that, i went through 2 KM head kits with bad rear landings....mine was on a KM Baja though with the rigid dom clone but your rigid pipe would also crack the head bolt as theres no flex to take some of the impact...i'd also expect a Zen or CY to go the same way if enough pressure was put on the head bolts, a 4 bolt would be stronger...

Is there any reasion why I would not want to cut the pipe and run it more like a header / pipe.. Using a tube between the two? I see other pipes set up like that, looks more forgiving... Just a thought / not looking to break my new engine...