two bad cylinders

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Mar 25, 2013 | 03:13 PM

4drf350

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Mountain Pass

Joined: Sep 2006

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From: Plain City Utah

two bad cylinders

Hi Everyone : I have a 289 in a 1967 bronco that I put in. the guy I bought it from said it ran good. When I tried to start it it would not start come to find out he put a bigger cam in an he also put a new timing gear set in it but he is a chevy guy an he timed it to a chevy after I played with it for a while I put he timing right I it started but # 5 an 7 dont really get as hot as the others . I did a compresion test an # 5 an 7 are around 80 ish psi the others are 120's. Does anyone know why it is doing that ? Thank for your help Rick

Mar 25, 2013 | 04:43 PM

nflfreak43

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From: La Vergne, TN

probably valve damage.. this kills me when someone times something and they dont have a clue and then pawn it off on someone else..

Mar 26, 2013 | 09:28 AM

4drf350

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Mountain Pass

Joined: Sep 2006

Posts: 157

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From: Plain City Utah

I did a compression test again yesterday an the some of the cylinders were 105 ( that is a little low I think ) an some were at 95 psi #5 an 7 an few others . I have headers on my motor an # 5 an 7 is not getting hot enought to burn off the oil that is on the header. I dont know what the compression should be for a 302 but most motor I work on is around 120 psi , when I compression test it the psi hold untell I release it . I dont know anymore . Rick

Mar 26, 2013 | 11:56 AM

nflfreak43

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From: La Vergne, TN

it should be 120ish.. but if it's slightly worn out it may be ok to 105 or so...

how did you retime it??

Mar 26, 2013 | 03:34 PM

4drf350

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Mountain Pass

Joined: Sep 2006

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From: Plain City Utah

I took the timing cover off an put the #1 to TDC an then alined the timing makes an it stated I know I am getting spark I checked that , I am going to do a leak down test today after work . Thanks again Rick

Mar 26, 2013 | 04:14 PM

nflfreak43

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From: La Vergne, TN

did you align the marks dots straight up??

it's likely a compression issue and not a timing issue..

Mar 27, 2013 | 09:21 AM

4drf350

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Mountain Pass

Joined: Sep 2006

Posts: 157

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From: Plain City Utah

Yes an I did a a leak down test yesterday , I put # 5 to TDC an I could hear air an feel air coming out of my valve covers where I put the oil in to feel it an where the PVC valve goes I an thinking I have bad rings . Please let me know what your guys thing. Rick