@hoonk @precisionguesswork @volvogod
Ladies and gentlemen, I love data driven diagnosis and technical approach to solving automotive issues. So as promised, here are my preliminary findings of my no start low compression problem
Before I continue, excuse my delayed posting but it was due to waiting for parts and being caught up with other jobs at the shop (as I run a one man shop). So get yourselves a cup of tea and relax will ya…?😌
Before doing anything else, I started off by cleaning the tappets and getting the stamped thickness numbers printed under the tappets ACCORDING TO THE ORDER I FOUND THEM IN. Here is the table:
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INTAKE:
V1=16.02mm v2=16.06mm v3=16.02mm v4=16.10mm v5=16.10mm v6=16.08mm v7=16.08mm v8=16.00mm
EXHAUST:
V1=16.08mm v2=16.08mm v3=16.02mm v4=16.02mm v5=16.00mm v6=16.00 v7=16.07mm v8=16.02mm
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Next, I figured that BEFORE I lapped the valves, I wanted to show the Sweedspeed community by how many millimeters does lapping tighten the valve clearance assuming that I spend an equal amountof time lapping each valve. And that, if my low compression problem was really caused by valves, it would be apparent when checking valve clearance. As of yet, my latter investigative question has been answered and the first will be answered tomorrow.
I used a piece of flat wood with a drilled hole to hold the Camshaft while checking two tappets per cylinder. I removed the valve holding springs and simply tilted the cylinder head and to the side and used a piece of wood to prevent it from falling off while pressing up the valve with my fingers. See the pictures.
Below are my valve clearances BEFORE LAPPING:
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INTAKE:
V1=0.20mm v2=0.20mm v3=0.20mm v4=0.15mm v5=0.15mm v6=0.20mm v7=0.23mm v8=0.25mm
[Cylinder 1] [cylinder 2] [cylinder3] [ cylinder 4]
EXHAUST:
V1=0.25mm v2= <0.05mm v3=<0.05mm v4=0.10mm v5=<0.05mm v6=0.13mm v7=<0.05mm v8=0.30mm
[Cylinder 1] [cylinder 2 ] [cylinder 3 ] [cylinder 4]
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Taking my original post compression numbers, the story makes sense as to WHY cylinder number 1 and 2 had low compression and improved slightly on the wet test (due to cylinder wash down) but number 2 remained low. The exhaust valves are not closing. And I bet it will get worse after I lap the valves. Please weigh in with what you think about my valve clearances.
Tomorrow I am lapping and grinding the stems accordingly.
Any tips on grinding the stems since I only have a bench grinder.😑
Thank you