Looking at crate motors - questions

joemomma

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After looking around and talking to several folks, I'm fairly well convinced that I want to go with a crate motor. My 302 has 156k on it, and while it doesn't smoke or use any oil, I have a feeling I'd be much better off going with a crate motor over rebuilding this one. I'll just have to wait a bit longer, as a crate motor would blow this "budget build" up. $2k for a budget H/C/I versus $5k for a complete crate (minus a few odds and ends which I'd have to purchase either way I go).

Anyway, I've looked at several vendors and they all say the crate motor isn't compatible with factory fuel injection. What do they mean by this? Is this something to do with the tune, or injectors/fuel lines/pump or what? It wouldn't make sense that you would have to go carb for all of these setups. What am I missing?
 

Chenn2389

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After looking around and talking to several folks, I'm fairly well convinced that I want to go with a crate motor. My 302 has 156k on it, and while it doesn't smoke or use any oil, I have a feeling I'd be much better off going with a crate motor over rebuilding this one. I'll just have to wait a bit longer, as a crate motor would blow this "budget build" up. $2k for a budget H/C/I versus $5k for a complete crate (minus a few odds and ends which I'd have to purchase either way I go).

Anyway, I've looked at several vendors and they all say the crate motor isn't compatible with factory fuel injection. What do they mean by this? Is this something to do with the tune, or injectors/fuel lines/pump or what? It wouldn't make sense that you would have to go carb for all of these setups. What am I missing?

I was looking into crate motors from blue print engines, their 302/351 based engines are all set up for carbs. Their cam profiles are what isn’t compatible with the EFI. I called their engineering department to speak to the topic specifically and that what it boils down to. I ended up just having a local shop build my stroker. It probably cost about the same as what a complete crate engine would cost with an 8 month lead time. It’s hard to find a company offering 302/351 based stoker engines for EFI and the ones that do are $$$$.

I’d just get a nice complete top end and rock your short block until it’s shot. And if you keep the 302 any local engine shop can refresh one of those reasonably cheap.
 

joemomma

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I was looking into crate motors from blue print engines, their 302/351 based engines are all set up for carbs. Their cam profiles are what isn’t compatible with the EFI. I called their engineering department to speak to the topic specifically and that what it boils down to. I ended up just having a local shop build my stroker. It probably cost about the same as what a complete crate engine would cost with an 8 month lead time. It’s hard to find a company offering 302/351 based stoker engines for EFI and the ones that do are $$$$.

I’d just get a nice complete top end and rock your short block until it’s shot. And if you keep the 302 any local engine shop can refresh one of those reasonably cheap.

Granted, I don't know shit about engines, but how does that even make sense? Not questioning you, just just trying to understand what isn't compatible with it. In the end, in sticking with the budget aspect, a top end kit would fit more closely to where I'm going. I have an Explorer upper/lower, just need cam and heads (and supporting parts - lifters, rockers, timing set, etc).
 

Chenn2389

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Granted, I don't know shit about engines, but how does that even make sense? Not questioning you, just just trying to understand what isn't compatible with it. In the end, in sticking with the budget aspect, a top end kit would fit more closely to where I'm going. I have an Explorer upper/lower, just need cam and heads (and supporting parts - lifters, rockers, timing set, etc).
I am assuming since our cars run off OBD I they are very sensitive to the cam. The IAC is what maintains idle with inputs from the O2 sensors, TPS, MAF, and VSS and air charge temp sensor. My new stroker even with a cam made for EFI struggles to maintain the idle. When I push in my clutch while coasting the rpms hang at 1300-1600 rpms until I come to a stop. This is a calibration built into the computer. The VSS tells it the car is rolling and it keeps idle speed up to makes sure you have brake boost, and the car doesn’t stall with all the accessories on. In stock form this fast idle usually would have only been between 1000-1100 rpms and not noticeable, but since I am now in heavy modified zone it’s hanging much higher. I am going to try a new IAC to see if it can help it out. While I was breaking the engine in the IAC was doing crazy shit and I was stalling stopping at lights, it’s stopped stalling but the fast idle is still high and the. The IAC fluctuating a bit when stopped.

Also it’s probably a liability and warranty thing. Since there are so many things that can go wrong on the crude Gen 1 EFI our cars run the companies don’t want to deal with it. The carb is much simpler make sure the jets are giving proper AF ratio and set the idle and the carb is jetted for the set up at the factory.

That’s just my 2 cents. I am no expert. This is my first Ford.
 

Adfalenski

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When I needed a cam, I went to the Comp Cams website. At that time, you entered all of your engine, driveline, intake, exhaust, and tire specs. Once all had been entered, a cam recommendation came out the other end. My chevy small block was destroked, custom pistons, rods, crank, 12/1 compression ported heads and mpfi. With that and the car specs they made a cam recommendation that worked great. Afterwards I found out the cam was one of their supercharger cam profiles. If you are building an engine, I recommend getting a cam profiled to what you are running. It rarely costs any more than an off-the-shelf cam.
 

joemomma

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I am assuming since our cars run off OBD I they are very sensitive to the cam. The IAC is what maintains idle with inputs from the O2 sensors, TPS, MAF, and VSS and air charge temp sensor. My new stroker even with a cam made for EFI struggles to maintain the idle. When I push in my clutch while coasting the rpms hang at 1300-1600 rpms until I come to a stop. This is a calibration built into the computer. The VSS tells it the car is rolling and it keeps idle speed up to makes sure you have brake boost, and the car doesn’t stall with all the accessories on. In stock form this fast idle usually would have only been between 1000-1100 rpms and not noticeable, but since I am now in heavy modified zone it’s hanging much higher. I am going to try a new IAC to see if it can help it out. While I was breaking the engine in the IAC was doing crazy shit and I was stalling stopping at lights, it’s stopped stalling but the fast idle is still high and the. The IAC fluctuating a bit when stopped.

Also it’s probably a liability and warranty thing. Since there are so many things that can go wrong on the crude Gen 1 EFI our cars run the companies don’t want to deal with it. The carb is much simpler make sure the jets are giving proper AF ratio and set the idle and the carb is jetted for the set up at the factory.

That’s just my 2 cents. I am no expert. This is my first Ford.

Makes sense - the OBD-I, while simple, isn't all that smart. It can't handle the change in profile outside of one of the mild "letter cams". I'd certainly want a tune once I went H/C/I. I suppose I'll stick with the budget H/C/I portion, and if it should fail down the road I can always go crate or stroker.
 

Daryl

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Sidebar question: what does H/C/I stand for? I have interest in this thread but don’t want to hijack Joemomma’s thread.
 

tvsn95

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back in the day a popular setup was 1.7 rockers ( they came on Cobra's) and a 5.0GT stock cam, seems the GT was a bit more than the Cobra cam.
Just sayin..
for idle try adjusting the stop screw in the throttle body, if you have a larger throttle body than stock then it is more difficult. I once took apart a cammed 302 that had the IAC blocked off with a gasket... 94-95 IAC, has a set screw that leaks air around the butterfly . try that first
 

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