predor hard to start after mods

[evile1003]

I bought a brand new hemi head predator. installed .308 dyno billet cam new springs billet rod billet flywheel stainless valves. after reassembling its almost impossible to pull start engine I got it to start one time.. checked timing and valve lash both seem good. btw I used the thinner head gasket... anybody that has any ideas would be nice

 

[trinik7597]

i would check the valve lash again !! does the 308 billet cam have a comp. release on it ?? wait is it a hemi head ?? that could be your problem right there i have read that the hemi head is only good to like a 275 lift past that you will have problems :thumbsup:

 

[trinik7597]

also with the wrong springs you could get coil bind !! and what push rods are you using ??

 

[evile1003]

from what I read everything should be bolt in. I spun the engine by hand didn't see any coil bind. valve lash is at .005 I believe.. I know its set to dyno cams recommendation. the problem is compression related. the push rods are stock

 

[trinik7597]

well you have not increased the comp !!! unless your cam does not have a comp release on it which i do not think it does . electric starter recommended on non comp release cams . when you ordered the cam did you tell them you are running it in a hemi not a gx200 ??

 

[OND]

I'm with Tim....maybe to much compression ...you might want to put the .040 headgasket back on it...and besure theres no coil bind.

 

[trinik7597]

also lash should be .003 running temp so you want to be almost 0 cold !! still think the problem is in the cam to hemi head . that cam is 320 lift to the valves and i know that i have read with out mods the hemi head is only good to like a 275 lift . someone who knows want to chime in on this ??? :thumbsup: hey eric you used a hemi head on your build what cam did you run ??

 

[OND]

Tim, I ran the Black Mamba from Tim Isky ...reason being I heard the same thing about the bigger cams and the Hemi head engine, Isky's cam is 274 lift and I ran the .041 head gasket...and flatmilled the head I think .020. or .030.
Black Mamba cam does have the exhaust compression release, and the engine cranks and runs great.

 

[evile1003]

Looks like I need to change my cam then... Question two would my stock cam last 1.5 hours this weekend with them springs I think there 32 lb whatever was recommended for 308 cam... Doesn't look like I can get the black mamba right now from here or nr... BTW thanks for the help

 

[OND]

Your stock cam would be worth a try...to see if it cranks and runs OK...might not turn the R's you want tho...and I would leave the .010 head gasket on it with the stock cam...JMO

 

[evile1003]

I was planning on doing that we backyard race this weekend I'm undefeated so far running a predator with bolt ons. But I've heard some chatter somebody built something to beat me and with our limited rules it wouldnt be hard to do so I wanted to have something faster in my backup kart just in case

 

[trinik7597]

slow down evile i am not saying i am right !! just what i have heard . there are a lot of guys who know more about the hemi heads on here i would wait and see what they say :thumbsup: maybe something pretty easy you can do .

 

[trinik7597]

and if it turns out that cam wont work for you i happen to have a new mamba maybe we could make a deal :thumbsup:

 

[evile1003]

ill prolly just brake down and buy a starter but in the mean time I just put the stock cam back in it left everything else the same... 8160 rpms was max on free load but I need to tweek the carb it running out of fuel and wont idle at all but I should be able to take care of that easy... them r's are impressive...

 

[David wulf]

If you have the billet cam from dyno it does not have the comp release on it , and you won't pull start it . The .005 lash you set is to much , I don't care what dyno says its to much . Set to 0 like Trinik said .