I have a question here.. I have a D15B7 that I blew last night.. I just put a custom turbo setup on it and it lasted about an hour.. Here the story..

The motor that I put in had been raced for a while by other people.. I got the motor and put it in my crx.. I started spraying it over the summer.. One day while I was spraying the vacuum line on the fpr came off and the motor started detonating and pinging really badly.. I let off the gas but it had done the job.. I pulled the head off and like 4 of the valves had chunks missing out of them, and they looked like they had been overheated really badly.. I then put on my Z6 head making it a mini-me and kept going but never sprayed it again..

Last night I finished my turbo setup and went out for the first time.. I was just starting to get into boost when it blew.. It wasnt a loud bang but just a pop and the oil light came on.. I checked the motor and cylinder #3's rod was broked off and came through the front of the block.. It broke about 1/2 way down but it was the upper part of the rod.. Looks like the rod broke away from the piston because the rist pin is still on the rod..

Here is my question, Does anyone think that me detonating the motor a few month ago with the nitrous did something to the pistons and the boost last night just finally gave it the power to break.. My A/F ratio was 12.5:1 when it blew and the motor wasnt pinging or nothing.. Any ideas here.. Thanks..

 

First of when you did the mini-me conversion did you run an oil line from the block to the head! If you did not, then that was the reason why your motor blew up, because once you boost an frankenstien and you don't have oil supporting it, under pressure and no oil the motor will lock up and the first thing that usually break are your rods! And if you did install the oil line, then let me ask you how much did you spray the d15 motor. The safe zone for a 1.5 liter engine is 50 shot of nitrous any thing above that is asking for it. When you were spraying and the detenation happened you probablly crack the piston ring gaps on the rod that broke off and when you installed the v-tec head and boosted the motor then the outcome happened! These are you possibilities why your motor blew up! Well this gives you anexcuse to do a motor swap, either an LS, B16a1( this would be the easy being the wiring and ecu are the same on 88-91 integra or the crx sir in japan), GSR,B20 or LS/V-TEC! IF I was you, I would save my money and go for a gsr and turbo and even without the turbo a gsr in a rex will be haulling assssssss!

 

Well heres the update.. I think the rod breaking didnt cause the problem, I think it was part of the aftermath.. The piston exploded.... The rod and rist pin broke completely out of the bottom of the piston..

I saw a hole in the block before I pulled the motor but now that its out there is also another hole in the back of the block... I can light in one hole and out the other.. Also part of the #3 cylinder wall is cracked off..

I pulled about 15 pieces of the piston out of the oil pan and im going to take pics of them, and whats left of the piston and the block so everyone can get an idea of exactly what happend..

jrcrx - Its a mini-me not a ls/vtec.. You dont need an oil line going from the head to the block.. There is a oil control jet that you pull out and it sends oil to the head that way.. Also I have a B18C5 type-r motor that I am in the process of building but I want to make sure I know everthing there is to know about tuning and running a turbo car before I put the type-r motor in.. I dont mind killing many d-series motors to learn but after putting like $5k or more into building my B18 I dont want it to happen to it..

I also already have another motor.. Its a D16Y7 that has like 20k on it or so.. Its the cleanest motor I have ever seen on the inside and outside.. Looks like it was never started