I'm not sure where to put this. I'm waiting on one last part to start my car up for the first time in a year, and I'm wondering if it even will. My new setup has an 8.8:1 compression and a 272 cam, anyone know if it will even run with the same tune? Am I risking damaging anything with the setup and breaking in the motor without a proper tune?

 

You took off the valve cover and prelubed the top end right? Or did this prior I hope. You should be able to start it up just fine, I would be logging as you do it for more in depth info on your engine. If your concerned you can (assuming you use and have the equipment for ecuflash) go into your high octane timing map and drop it a couple degrees and same with your Fuel

 

Everything has been prelubed and all, mechanically I'm not concerned. I was previously tuned at 12psi using ecuflash but was running on the rich side (10.5-11.0 afr), was more just concerned since I dropped my comp ratio and have the big cam now. Guess I'll just start it up

 

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Ummm.. Heads up for ya, cuz the last 3 people in a row(including myself) with built motors has had this issue.. Make sure someone Primes the oil pump with greese! other wise ur pump will not push/pull oil. Big change in compression shouldnt change ur startup much, everything else is similair to the old setup other then that compression change and different cam. as long as ur injectors are still the same, i dont see why it wouldnt start and fight to idle.. It will need some tinkering

 

I didn't have this problem with my motor. I disconnected the fuel pump, injectors and coils and let the motor prime itself. Disconnect the oil feed line from the turbo so you can tell when oil has made its way through the pump and to the turbo. I've done this with every motor I've built over the past decade and have yet to have an issue as a result. It's strange to hear people having issues getting their motors started.

 

That's how I've always primed my turbos in the past. I'm still waiting on a coupling for my intercooler pipe, expected it a couple days ago. And a couple issues with my MAF swap, once those are resolved I'll get it started.

 

Dry oil pumps (that have been pulled off and cleaned while the motor was vac’d/hot bathbathed or cleaned) have issues with pulling pressure when there is no fluid inside it already. its actually a very common issue with fresh built motors.. This is why Most all Crate motors come Primed with grease in the oil pumps, because it won’t fall out, and will push through the system without issues (since its petroleum based) it dissolves in oil once its all mixed together.

If all you did was pull the head and pan and swap pistons/rods you shouldn’t have any issues.. but a dry motor will normally require the oil pump being primed.

Why do you disconnect all that? All you have to do is disconnect the crank sensor, and it wont start, injectors dont fire, and spark plugs dont fire.. thats how mitsubishi primes our motors..

 

Well, I had a couple other issues to fix, but I got the car started and idling and drove it around the block for the first time in a year. I think i've got a vacuum leak since it idles around 10 hg so I will have to track that down, and it is running lean probably due to the cam.

 

^^ good to hear...



mines only pulling about 5in-hg since we got it running.. ill see 18ish sometimes when im on a decel or gear change. havent figured out if i have a leak somewhere or some type of valve issue going on... or its all just normal and fine..

 

Or lean due to the vac leak!

 

Ive messed with my latencies and injector scaling and am no longer running lean. I'm going to drive it around a little out of boost while the motor breaks in. I hit ~5psi and didn't hear anything that sounds like a boost leak so I guess i will wait and see once the motor breaks in a little more.