ok, I have searched and read for the past 3 hours, posts from now, all the way back to 2004, and have a huge headache and am more confused than when I started.
Here is what I have and what has happened.
93 gt 180,000 miles with about 30,000 on gtx turbo goodies,
gtx turbo/manifold
gtx injectors
CS downpipe
rx7 na maf
upgraded fuel pump and others
I have read and understood that (correct me if I am wrong) these engines handle up to if not more boost on stock settings. I had good results with stock 8.8 boost. 196hp/198tq on dyno about a week ago. Bought a hallman boost controller and increased boost to 12 pounds, Figured I was ok with that setting, a/f through aem wideband was reading 12-13. I had a little bit of boost creep but just eased up to wot to help correct that. Anyway, didnt really know what detination sounded like until yesterday/today. Didnt hear it until wot and a/f were still good, then ran rough and clunked and smoked....blah,blah,blah, hole in pistion, so I think, pulling the head on monday. I had just changed the spark plugs (NGK) before this happened and they were brown and also added the rx7 maf which I was told was from an rx7 turbo but found out later today (after the boom) was not. The engine ran super rough at idle and to get it to run enough to stay running at idle I had the distributor turned all the way towards the firewall. When on the gas engine ran nice and smooth with no issues, and seemed ok, I was not beating on the engine and was on my way to get the timing checked as I knew something was wrong, but I never made it.
Now here are my questions... I have a spare bp engine with 60k. I am gonna drop that one in and want to know what you guys think I did wrong. I have a ms system that I am going to be putting in shortly, still need somethings for it.
Why did I have to adjust the timing so much for it to run?
Is the stock compression ratio 8.8:1 on the bp enignes? If so, from the last 3 hours of reading, then the piston bs should not have happened with such small boost, unless I have other issues.
Please try and understand that I have read and searched, which that is not the best search engine I have seen, these forums for info. I have read alot of conflicting info and am trying to have a reliable yet powerful engine. Since the engine is out, I am going to go with gtr rods and wiseco pistons, I would like to stay stock size, no boring if possible. That is about all I have been able to understand from the reading. I understand all the injector info and turbo differences. Its the internals of the engine that are confusing me. I would like to stay with a low CR so I can have a bigger range for error. I am going to purchase a rebuild kit for the engine and replace the oil pump, water pump and get the mazda oem head gasket. Gonna get the injectors flow tested or hopefully get some gtr ones.
Should I balance the crank?
My head hurts and cant think of anymore questions at the moment, I know have I more but its a start. Thanks
Here is what I have and what has happened.
93 gt 180,000 miles with about 30,000 on gtx turbo goodies,
gtx turbo/manifold
gtx injectors
CS downpipe
rx7 na maf
upgraded fuel pump and others
I have read and understood that (correct me if I am wrong) these engines handle up to if not more boost on stock settings. I had good results with stock 8.8 boost. 196hp/198tq on dyno about a week ago. Bought a hallman boost controller and increased boost to 12 pounds, Figured I was ok with that setting, a/f through aem wideband was reading 12-13. I had a little bit of boost creep but just eased up to wot to help correct that. Anyway, didnt really know what detination sounded like until yesterday/today. Didnt hear it until wot and a/f were still good, then ran rough and clunked and smoked....blah,blah,blah, hole in pistion, so I think, pulling the head on monday. I had just changed the spark plugs (NGK) before this happened and they were brown and also added the rx7 maf which I was told was from an rx7 turbo but found out later today (after the boom) was not. The engine ran super rough at idle and to get it to run enough to stay running at idle I had the distributor turned all the way towards the firewall. When on the gas engine ran nice and smooth with no issues, and seemed ok, I was not beating on the engine and was on my way to get the timing checked as I knew something was wrong, but I never made it.
Now here are my questions... I have a spare bp engine with 60k. I am gonna drop that one in and want to know what you guys think I did wrong. I have a ms system that I am going to be putting in shortly, still need somethings for it.
Why did I have to adjust the timing so much for it to run?
Is the stock compression ratio 8.8:1 on the bp enignes? If so, from the last 3 hours of reading, then the piston bs should not have happened with such small boost, unless I have other issues.
Please try and understand that I have read and searched, which that is not the best search engine I have seen, these forums for info. I have read alot of conflicting info and am trying to have a reliable yet powerful engine. Since the engine is out, I am going to go with gtr rods and wiseco pistons, I would like to stay stock size, no boring if possible. That is about all I have been able to understand from the reading. I understand all the injector info and turbo differences. Its the internals of the engine that are confusing me. I would like to stay with a low CR so I can have a bigger range for error. I am going to purchase a rebuild kit for the engine and replace the oil pump, water pump and get the mazda oem head gasket. Gonna get the injectors flow tested or hopefully get some gtr ones.
Should I balance the crank?
My head hurts and cant think of anymore questions at the moment, I know have I more but its a start. Thanks
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