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Compression & Fuel Pump


Darren Groves

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I kind of know the answer to this question, but thought I'd share it anyway just for some group discussion  :)

 

Trying to coax a 2L MK1 Vitesse back into life after a restoration that stalled many, many years ago. The engine turned freely by hand, so we set about trying to get her running, after a short period it was obvious nothing was doing. We had a good spark and the static timing was set, valve clearance set, we got fuel into the carbs, so decided to do a compression & leak test.

 

The results were:

 

No. 1 - 150psi (Dry) / 220psi (Wet)

No.2 - 50 / 70

No.3 - 45 / 90

No.4 - 95 / 160

No.5 - 105 / 175

No.6 - 135 / 175

 

Obviously plenty of loss through the rings and low readings, leak test showed a selection of valves not seating well also.

 

Any nuggets of wisdom from anyone before I get the engine crane out?

 

Also, the fuel pump (old fashioned glass bowl type) that has been fitted works a treat if you manually operate the internal or external levers, but does nothing fitted to the car. Removed the pump, turned the camshaft until I could feel the lobe reach it's high point, refitted the pump and there was little on no contact between the lobe and pump lever. I guess it's just the wrong pump....

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Might not be rings, might be head gasket. How old is the fuel? Old fuel can go off in  a short space of time. If you're getting fuel into the carbs (presumably from the manual prime lever) are the plugs wet with fuel? If not, could be manifold gasket leak. Try some of that quick start stuff. Certainly change the fuel pump, make sure you get the right one!

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that pump was used across a whole lifetime of cars, and like the modern crappy ones there is a whole range of differing levers to suit all makes

 

is there a spacer you can remove ? on the block face?

 

were the results throttles open and plugs out ???

 

I would start with head gasket Ive never found a wet test very convincing about the outcome

 

Pete

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I've got a little more history on the engine....

 

The engine was running fine, the head was removed and had new valve seats and valves fitted by a reputable engine reconditioned. Everything refitted but the car was never run again as it was undergoing a body off resto, but this was 15 to 20 years ago......

 

In answer to some of the questions:

 

Fresh Fuel

Test done with open throttle and plugs out

Plugs dry, but plenty of fuel in float chamber

No spacer on pump, just paper gasket

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anything  odd doing the tappets which may point to gummed valve stems sticking from lack of use ??

 

so why i wonder would they do a top end rebuild if the whirling bits were showing signs of being shot,

 

to get as low as 40 makes for  valve problems   i reckon you would get 40 with a sink plunger fitted   Ha  !!!

 

may be the build was not as reputable as thought ....head off.... look in 

 

whats the engine you get these sort of results if its fitted with a recessed block and wrong gasket 

what the engine number  ????

 

 

 

Pete

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Have you chucked redex in and left the rings to soak? then a good squirt of oil, plugs out spin the motor. Then a squirt of petrol in the carbs while starting it? Once going it may just sort itself out....you may get lucky. 

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Engine No. Is HCxxxxx, can get full number tomorrow if there's a brake between recessed and non.

 

The engine was running fine when the resto was begun, the head had the work done so it could be converted to unleaded. Head refitted but never run, that was 15 plus years ago.

 

Nothing odd when setting valve clearance, everything seemed normal, but will go through it again.

 

It got a fair bit of Easystart in it, didn't even think about going, not even a cough.

 

I have left the bores soaking in penetrating fluid overnight in the hope it improves things just enough to get going. Like you say Clive, if get the engine running and hot and it may fix some of the issues.

 

I guess there's no harm in re-torquing the head? Will check manifold bolts also.

 

Any other infor welcomed!

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Hc is vitesse so wont have the recessed bore

make sure the HG has no little rectangular tag sticking out the back edge, these can only be used on recessed like later GT6 and 2000/2500

If there is a tag its very wrong and needs to be changed

its not the first time unleaded inserts have dropped out./loose fitting.

 

40 is very low something should be fairly obvious , but needs a strip out to find it

 

do a retorque and any easy tries first, but think you will have the head off by the weekend

 

Pete

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Still no better this morning, so off came the head.

 

This was a reconditioned head, albeit many years ago, but you'll see from the first 2 pictures why No. 2 was so bad. These 2 photos were taken around 20 minutes apart. I've only removed 4 of the valves so far, the mating faces were very shiny on all of them (doesn't show that well in the photo), just like they were fitted without being lapped in.....I guess we'll never know.

 

I filled the 6 bores with the same volume of fluid, within 1 hour 2 were completely empty, 2 had a small puddle, 1 had lost around 50% and the only one with half decent compression retained most. So not great news really.

 

post-31-0-72072900-1462386365_thumb.jpg post-31-0-61148100-1462386396_thumb.jpg post-31-0-82589000-1462386418_thumb.jpg

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 If you pour stuff into the bores, do some disappear quicker than others? When I say bores I mean block not head.

 

I filled the 6 bores with the same volume of fluid, within 1 hour 2 were completely empty, 2 had a small puddle, 1 had lost around 50% and the only one with half decent compression retained most. Engine out next week, hoping for just rings and a hone, but will have a measure.

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it makes you wonder how sick was the engine to have the head work done when it must have been using lots of oil and blue smoke, which is not  really head related ,

 

 to lap valves i oil the stem , a good smear of paste and use a battery drill to rotate reverse driving the stem.  works a treat 

 

   lift the head frequetly to keep the paste from spinning out ,  (drill on slow )

 

   Pete

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  • 4 weeks later...

This engine is all rebuilt now, start and runs...sounds nice.

 

Still have an issue with the pump. Just to recap it pumps fine manually when using either of the levers, but the lever isn't travelling enough on the cam lobe. The pin the lever pivots on was broken, so this was fixed, but still not enough travel. The pump just has a paper gasket, so it's not an incorrect spacer, so was thinking about building the lever up with 3-4mm weld which should be enough to operate the diaphragm and valves, any reason why I shouldn't do this?

 

As you can see from the photo it is making contact with the cam, but only enough to take up the slack in the lever.

 

post-31-0-79296400-1465309443_thumb.jpg

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Darren its difficult to tell with the angle of the picture but the lever looks to be in a high position compared to mine Not sure that helps or if any one else agrees but mine was quite difficult not to get under the cam when I fitted it

 

Aidan

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