"franken-lima" build idea...

[Mikel89us]

Yea, but it would be easier to post links here or just get the 4 banger guys to get moddedmustangs.com accounts. They would all benifit. I dont know if there was a thread about 2.5 potential, im sure its been there at some time, but i was doing some brain picking of OHC230 through personal chat. I have been trying to decide exactly what to do with my car AND Ranger.

 

[DJ2.3]

What is the big drawback to using the 2.5 rods and piston? I noticed the 2.5 pistons are dished quite abit, but i figured that could be overcome by milling the head down to the intake bolt holes. Are the rods that much weaker than the 2.3? I have a low mileage 2.5 laying around and was hoping to do a low buck stroker, but i want it to be able to run 7000 rpms without worrying about it.

 

[4b316]

no drawback to using the ros and crank.bolt in deal.guys that race do it all the time.7000 is on the low side of rpm,s,most of the guys that run them are running between 75-7900 with stock stuff and some turn 8,biggest thing is to get valves not to float and enough fuel.we run our 98 2.5 at about 6600 with stock EFI,wacked head about 60 thou,and self built header.We have a moates chip that raises rpm level and picked up a little timing advance at 4400-5500

 

[19bonestock88]

yeah, RPM isn't a huge issue with these engines... my 2.0 will spin 6800(no useable power there) without having problems... i think the 2.5 rods are out of the powdered metal(not entirely sure) and the pre 94 2.3 rods are forged(sure about that)... they have the same numbers as a 1974 2.3 rod

 

[DJ2.3]

thanks 4B, that what i wanted to hear. I know alot of guys are spinning stock 2.3 bottom ends up to 8k but i wasn't sure if the 2.5 bottom ends help up as well.

 

[Mikel89us]

I actually used to run a stock 2.3 with stock cast pistons at 8300 max in my old racecar, now i dont recomend it, its not safe, but i did it.

I think the head design of the 2.5 is a bit different vs the others causing the need for the slight dish in the pistons. to keep the C/R at 9:1 plus the longer stroke. They dished the piston to keep from changing everything else.

 

[19bonestock88]

i have another idea and a question that goes with it. i have a slight fear of going to EFI(wiring and such) so i thought about just running a EFi lower intake(ported and knife edged and not sure about the injector holes) with a small 4bbl carb... maybe a holley 350? smaller? i know i would give up some power, efficiency, and driveability, but what do you guys think? kinda gives and old school hodrod vibe...

 

[cody93]

the efi intake is only good if you plan to have it wide open as they make power in the higher rpms. if not i wouldn't bother..

 

[19bonestock88]

okay... if i stay carbureted, it will be with a ported 2bbl intake and a weber carb...

 

[Mikel89us]

Really porting the intake only does good for high rpm too. If you have to pay someone to do it i wouldnt bother. Now i disagree with the EFI lower not being good for low end. They have equal runner lenghts which has MANY advantages. I have one, i used to use it on my racecar, and it was better all around. I would suggest using a holley 350 cfm 2bbl carb. The 500 2bbl was too much for launch for my car, but we didnt have the money to buy a new carb. Also the holley 350 will bolt to your stock 2bbl carb intake if you take the small carb adapter off (if you didnt know this already) and will make an improvement in power. Its hard to tune the stock carb intakes because the runner lengths are all jacked up.

My suggestion is to use the intake you have, if you have an EFI, go ahead and modd it, the adapter plate for them is $100. If you have the carbed intake, use it in stock format unless you are cleaning it up yourself. i would still not do much to it.

Keep in mind that anywhere fuel flows across the intake or head runners you want a slightly rough surface. a smooth surface will cause the fuel to settle on the wall (lack of turbulence to keep it mixed in) and promote fuel pooling. This can cause undesireable running conditions especially at lower rpm. Also it may cause poor fuel mileage due to improper tuning.

 

[Mikel89us]

I have also done the calculations, and the proper size carburetor for a 2.3 at 8K RPM is only a 280 CFM carb. Many engine builders say that you will get more power with a slightly smaller carb than one that is slightly too large, and i believe them, however, its too hard to find a good carb that small. So the Holley 350 is your best bet.

 

[19bonestock88]

how many CFM is the weber DGEV? that was my first choice in carb as it has been used successfully by many 2.0 ranger owners

 

[Mikel89us]

how many CFM is the weber DGEV? that was my first choice in carb as it has been used successfully by many 2.0 ranger owners

Im not sure exactly, but i do know its less than 220. I t should be close to that. It will work well! The holley 350 just has a greater parts availability.

 

[19bonestock88]

less than 220 CFM? that seems possibly adequate for a 2.5 revving to... how high would such an engine have to rev for peak power? 6200? 6500? 7000?

 

[Mikel89us]

Max with a stock cam is 5500