| Author | Message | ||
     David Lacey Experienced User Username: dlacey Post Number: 101 Registered: 11-2010 |
All, I am trying to rescue an abandoned Bentley S3 with the early 6.2 V8. I ask here in the Shadow forum as there's likely more V8 knowledge here. With the plugs out it will turn about 20-30 degrees (by turning the flywheel, laying under the car)..in either direction it is then stopped by quite a solid blockage... In the section where it turns it's moving quite freely, but then something's hitting.... Could this be stuck valves?? Is it an 'interference' engine?? I will get a cheap eBay borescope and peer inside to try to find the blockage. Any suggestions/theories/experience most appreciated! Dave | ||
| Mika Rikkinen Yet to post message Username: mri Post Number: 1 Registered: 10-2020 |
I`d take valve covers off and ask some one checking valve movement while turning engine. If valve stuck, what is a good guess, You should be able to spot it. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 735 Registered: 07-2018 |
Look for bent push rods too. Get the borescope, you will find many uses for it. Mine has 3 camera's on the end, on on the front and 2 on the side, 180 degrees apart. (you can get one with a shorter extension) https://www.amazon.ca/dp/B0C3H1N8VQ?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1 | ||
| David Lacey Experienced User Username: dlacey Post Number: 102 Registered: 11-2010 |
OK, got me a nice AliExpress borescope and got a look in all cylinders...in some I can see valves open:  and the cylinder walls indicating piston is way down. And in A1 I have valves closed and piston near the top:  All black and grimy but there's valves up top and piston across bottom. Certainly no evidence of open valve hitting piston. So next step, per your advice, will be remove valve covers and rocker shafts (all valves *should* be closed) and see if it turns. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 830 Registered: 07-2015 |
Rust line on the bore? | ||
| Mika Rikkinen New User Username: mri Post Number: 2 Registered: 10-2020 |
By the looks of that one valve I`d remove cyl heads and have heads done... Rust in valve seat, might cause leak some point. And that is not only valve that has been open while car was abandoned. And like Michael said there might be rust on bore because open valve(s). Check leak holes in the block, there is one hole for each cylinder. If leaked coolant or oil You have to remove engine and take out liners. Don`t do like I did and remove first heads an then engine! :-) | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 2364 Registered: 05-2012 |
Mika Why do you warn about removing the heads first? | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 831 Registered: 07-2015 |
Because it would have been easier with the engine out. | ||
| David Lacey Experienced User Username: dlacey Post Number: 103 Registered: 11-2010 |
Progress! I removed the rocker shafts and checked all valves closed. I checked all pushrods & none are bent. Under the car i tried to turn the engine again and it was still stiff at certain points, but i could 'push though' and get the engine to to a full revolution. (more confident to push hard now I know the valves are all out of the way). Yes, it seems there's some light rust in the bores and some rusty valve seats. In my experience on other engines, rusty valve seats will clean-up in use. The cylinder bores could be a major issue. So, today I am gonna try kerosene/ATF mix down the bores and spinning the engine on the starter (Plugs out, valves closed) After that I will inspect the bores again. |
