No compression on one cylinder

General Chat About Engine Build

Moderator: phpBB2 - Administrators

Post Reply
N40toy
Newbie
Newbie
Posts: 2
Joined: Sun Aug 20, 2017 2:09 pm
Location: Bridgend

No compression on one cylinder

Post by N40toy »

Afternoon all, I was wondering if anyone could help. My 3.5 v8 rover engine has zero compression and the cylinder next to it has 50. Car uses a little bit of water, uses no oil. Any thoughts?



DEVONMAN
Top Dog
Top Dog
Posts: 1440
Joined: Sat Dec 13, 2008 2:46 pm
Location: Croydon UK

Post by DEVONMAN »

Which number cylinders are they?
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


Image

N40toy
Newbie
Newbie
Posts: 2
Joined: Sun Aug 20, 2017 2:09 pm
Location: Bridgend

Post by N40toy »

I'll check with my mechanic in am bu think he said it was cylinder 5. Did try to private message you not sure if it went through? New to this site. What you thinking?

unstable load
Top Dog
Top Dog
Posts: 1278
Joined: Mon May 04, 2009 6:53 am

Re: No compression on one cylinder

Post by unstable load »

N40toy wrote:Afternoon all, I was wondering if anyone could help. My 3.5 v8 rover engine has zero compression and the cylinder next to it has 50. Car uses a little bit of water, uses no oil. Any thoughts?
Does the car have a noticeable misfire?

Could be a stuck valve or a holed piston. As for the low pressure, how much are the other pistons' pressures?

The easiest way to see what it is is to connect an airline to the cylinder and apply light pressure. If it's a valve, it will come out the inlet or exhaust, if it's a piston, then it will come out the oil filler.
Cheers,
John

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

N40toy wrote:I'll check with my mechanic in am bu think he said it was cylinder 5. Did try to private message you not sure if it went through? New to this site. What you thinking?
Ah - this isn't something you've measured yourself?

True zero would be most unusual without other symptoms. It would need a hole in the piston, or the cam so worn a valve wasn't opening, etc.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

Post Reply

Return to “Engines Area”