interferance engine??????
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From: Menomonee Falls, WI

are our engines, series 1 or series 2, interferance engines?????????
i mean if the exhaust vavle or intake vavle are at a full open condition, will the pistion hit the vavle?....the engine nuts would be able to chime in on this one.......if so this would make the timing chain integrity a must!!!!!!!!!!!!!!!!!!!!!!!!!!!
thanks,
nicky!!!
i mean if the exhaust vavle or intake vavle are at a full open condition, will the pistion hit the vavle?....the engine nuts would be able to chime in on this one.......if so this would make the timing chain integrity a must!!!!!!!!!!!!!!!!!!!!!!!!!!!
thanks,
nicky!!!
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From: Menomonee Falls, WI

crazy, id better get crackin on my timeing chain change before 200000, as anyone on the club ever had their chain brack and piston impact their vavle? If so how bad was the damage?
nicky
nicky
From what I've personally seen, chain breakage is very rare. I have 220K on my original chain. I have no plans on touching it until the time comes to rebuild the motor.
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I feel that there are a few things you need to look at...
The stock lift on a 3800 is .250 intake and .255 exahust( Too lazy to look up the numbers for diffrent years as they stayed pretty close) then multiply by 1.6 and you have the totall lift at the valve...
I think it should be .400 intake and .408 exahust...
The look at where exactly the valves are located in relation to the dish in the piston... Will the vlaves be in the general area of the dish?
The the compression.... The 8.5 to 1 compression pistons have a decent dish in them, if you look at the series II NA'd 3800 the 9.4 to 1 compression pistons are almost flat...
I have never seen an 8.5-1 compression 3800 kill a valve... But I have seen the old school 3.0 Buick V6 9.0 to 1 compression crush valves when the timming chain went...
But the cam lobe lift was 3.89 using conventional lifters... Each piston had 2 valve marks...And one cylinder had a chunk of valve imbeded in the head and piston... Not pretty...
But then again I have yet to hear of an 89-current 3800 jumpping time , or for that matter crushing valves... But I'll bet as we see more performance I'll bet someone will find out for sure... Hopefully not here on BC tho..
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The stock lift on a 3800 is .250 intake and .255 exahust( Too lazy to look up the numbers for diffrent years as they stayed pretty close) then multiply by 1.6 and you have the totall lift at the valve...
I think it should be .400 intake and .408 exahust...
The look at where exactly the valves are located in relation to the dish in the piston... Will the vlaves be in the general area of the dish?
The the compression.... The 8.5 to 1 compression pistons have a decent dish in them, if you look at the series II NA'd 3800 the 9.4 to 1 compression pistons are almost flat...
I have never seen an 8.5-1 compression 3800 kill a valve... But I have seen the old school 3.0 Buick V6 9.0 to 1 compression crush valves when the timming chain went...
But the cam lobe lift was 3.89 using conventional lifters... Each piston had 2 valve marks...And one cylinder had a chunk of valve imbeded in the head and piston... Not pretty...
But then again I have yet to hear of an 89-current 3800 jumpping time , or for that matter crushing valves... But I'll bet as we see more performance I'll bet someone will find out for sure... Hopefully not here on BC tho..
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