Moparts

Rebuilt engine, no compression, spitting gas, help

Posted By: sco440

Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:19 PM

Newly rebuilt 440. Went to start for the first time and it is not building up any compression, is spitting gas through the Eddy carb. It was completely rebuilt all new parts basically to stock. Is this a camshaft issue? THX
Posted By: Challenger 1

Re: Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:29 PM

Originally Posted By sco440
Newly rebuilt 440. Went to start for the first time and it is not building up any compression, is spitting gas through the Eddy carb. It was completely rebuilt all new parts basically to stock. Is this a camshaft issue? THX



Lifter pre load, did you check it?
Posted By: smos001

Re: Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:30 PM

Sounds like a cam timing issue... valves are stuck open... also check valve lash if you have adjustable rockers (did you say all stock?). check for bent push rods. If the cam is off timing you could bend them.
who built the engine? Did they break it in yet?
Good Luck,
Posted By: lewtot184

Re: Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:32 PM

spitting thru the carb may mean the distributor is 180 out. simple fix.
Posted By: smos001

Re: Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:40 PM

No compression?
Posted By: stumpy

Re: Rebuilt engine, no compression, spitting gas, help - 07/31/15 10:42 PM

Originally Posted By smos001
Sounds like a cam timing issue... valves are stuck open... also check valve lash if you have adjustable rockers (did you say all stock?). check for bent push rods. If the cam is off timing you could bend them.
who built the engine? Did they break it in yet?
Good Luck,

iagree Cam timed wrong.
Posted By: RapidRobert

Re: Rebuilt engine, no compression, spitting gas, help - 08/01/15 02:38 AM

I would regoop the cam. set dampener at 15 BTDC. check the lobes when you regoop to see if you are on #1 or #6 compression & clock the rotor accordingly. turn housing so magnet is dead even with the tooth. make a mark on the dampener 2&7/32" CW from the TDC slit & have your dist man set it to that when it fires (vac adv capped). carb bowls filled. batt charged. fan in front of rad. front end jacked up. thermostat OUT. read "breakin secrets" at www.mototuneusa.com goose the throttle many many times during the 25 minute breakin. during mockup confirm lifters are free to rotate (hughes engines procedure).
Posted By: Kern Dog

Re: Rebuilt engine, no compression, spitting gas, help - 08/01/15 04:45 AM

You are probably very frustrated but you'll need to give more info if you want any useful help.
Posted By: Cab_Burge

Re: Rebuilt engine, no compression, spitting gas, help - 08/01/15 05:29 AM

Who rebuilt it? If you did the build did you install the cam with the dots on the gears or did you install the cam and and degree it? If with the dots on the gears did you aligned the crank gear dot out under the teeth or the one on the inside above the crankshaft key? If the one above the key you need to use the one on the outer edge of the crank gear. If you didn't do the build call the one who did and tell them to come fix it up Let us know what youy find and do, it will help a lot of others on here also up
Posted By: sco440

Re: Rebuilt engine, no compression, spitting gas, help - 08/01/15 07:38 PM

I have some compression maybe 50 lbs not enough for it to run.. I think the engine builder didn't perfectly line up the dots on the cam and crank sprockets when he put the timing chain on.
Posted By: Cab_Burge

Re: Rebuilt engine, no compression, spitting gas, help - 08/01/15 10:18 PM

To make it spit gas up out of the carb while cranking on the starter the valves have to be opened shock work The cam is out of time, have the builder correct it or maybe have someone who knows more than your builder help you reinstall the timing gears and align the dots proeprly work I think you should really degree the cam for the best performance also up
Posted By: RapidRobert

Re: Rebuilt engine, no compression, spitting gas, help - 08/02/15 05:45 AM

What Cab said, if it is dot to dot (correct dots that is!) it'd still have good compression even with the dist 180 out. With a multiple keyway gearset its confused some to line up the cam gear wrong. inner marks are for adv/ret/straight up phasing. outer marks (closer to perimeter) are for dot to dot
Posted By: 70Cuda383

Re: Rebuilt engine, no compression, spitting gas, help - 08/02/15 06:41 AM

If the wrong dot was used in 'dot to dot' the cam can be as much as 30 degrees advanced/retarded. Recipie for Pistons to hit valves. DAMHIK.
© 2024 Moparts Forums