Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings?

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Sat 29 Dec 2018 19:31
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

Hi Guys. Im in the process of rebuilding a project Ferrari 308 (purchased as a non runner)

Im filming the progress as I go along.

Would really appreciate some helpful feedback and suggestions regarding my Cam Timing.

So far; have run a compression test and my front bank of 4 have a ok reading between 155- 170

However my rear bank of 4 cylinders are all between 50-55 ?

Do you think my cam belt has slipped a tooth ?

Any help would be appreciated.

Video of the problem here:

youtu.be/JlbOdrkD2DA

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Sat 29 Dec 2018 22:24
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - elekie&a/c doctor

I think you will find these have 2 cambelts ,one for each bank. Time to buy a workshop manual. Even if the timing is out,the belts will need to be replaced as part of routine service .There are many reasons for low compression. So more investigation required.

Edited by elekie&a/c doctor on 29/12/2018 at 22:39

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Sun 30 Dec 2018 10:29
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

Thanks for the reply

Yes two cam belts, Ive started to remove the cam covers today in this video

youtu.be/xYpXpNhj-bc

you can see the rear belt (good compression bank) is good no cracks, I'm just about to remove the front cam belt cover to see and check timing marks.

I did discover a very badly split air hose that feed into the plenum, wondering if that could have an effect on compression readings ?

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Sun 30 Dec 2018 11:50
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - elekie&a/c doctor

Judging by the questions being asked here, it would appear that you only have limited knowledge of how an engine works. Please don't get me wrong. I am up for anyone taking on a project as a learning experience, but a car of this calibre is probably not a good starting point.

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Sun 30 Dec 2018 18:21
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - focussed

I think you may have just found out why the car was sold as a non runner - The rear bank cam belt jumped a few teeth and has bent a few valves, is possibly the reason for the low compression.

Engine out and sort it out on the bench so you can see what you are doing is my advice.

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Sun 30 Dec 2018 18:30
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

Yes always the gamble with non runners. I don't mind though all part of the learning with an engine out job.

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Sun 30 Dec 2018 22:53
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - edlithgow

i'd asume you probably have another car. If so, it might be an idea to learn a bit on that first.

I bought a Lada 1200 off some friends who had replaced it with a fairly high performance (hough not in the Ferrari league) Japanese car with some problems (Celica 4WD Turbo I think? Quite a jump anyway) and they said the learning on the simpler car had been invaluable.

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Thu 3 Jan 2019 03:14
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - hardway

I'd suggest you buy a compression leakage tester.

not that much of an investment for such a useful tool,

It's used to inject compressed air into a cylinder.

Mine uses twin gauges,

100 psi in and the second gauge shows holding pressure

100 would be ideal but say gauge 2 reads 80 psi holding,

clearly a leak which then can be traced by sound,

if it's hissing from the intake then the intake valve is not sealing

and so on and so on.

it's a bit more complicated than that but it'll come with instructions.

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Wed 9 Jan 2019 18:01
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

Update today on the ferrari 308 .... really good news

youtu.be/40JN0wgsEqs

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Tue 15 Jan 2019 18:33
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

looking good still, installed two new cam belts and tensioners

youtu.be/PlKtE6OYHCE

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Thu 24 Jan 2019 18:55
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - Ratarossa

Got its running and driving !!!

youtu.be/MnDYuNbwqXk

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Fri 25 Jan 2019 22:31
Ferrari 308 - Ferrari 308 QV Project HELP Compression Readings? - focussed

Well done! - rather you than me crawling about under cars on your drive this weather!

Great that you video-ed it.

I reckon there ought to be a special HJ award for this - a complementary HJ titfer maybe?

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