help turboing motor

[Anonymous]

I have 2 250 ci motors 70 and 77 which one do i turbo and I would like to get as much help as possible. I would like to know what turbo, gaskets ad pistons and what ever other parts I may need any help would greatly be appreciated.

 

[wallaka]

The 77 should have the better head and Duraspark ignition. Other than that they are identical. As for turbos, the optimal would be like a T04/T4 "S3" trim with about a .70 A/R. I think that a Holden HX40 off a Cummins would be a good starting point as well. A GT40RS would be great, except they cost a couple grand each.

It all depends how much you want to spend. Same with pistons. Hypers or forged is the way to go, but pricey.

Swap to a direct-mount 2bbl for carburetion such as the 350 or 500 Holley.

There's an ongoing debate about head gaskets. Look at the thread "O-Ringed 250 Block".

 

[hasa68mustang]

and Ill chime in before linc200 does, go with the 350 cfm holley they are bettter.

 

[Anonymous]

Since I have 2 heads i was going to take one of them and have the log machined off and making it efi head and making custom intake. I would like to use two small turbos that i can change the boost on. I will try to post some pictures of the head modification once i get started on it.

 

[Anonymous]

Two small turbos will make things much more complex and expensive.

Did you get the chance to read the FAQ at the top of the forum?

 

[XFlow_Fairlane]

might wanna look at my modded log EFI project in this forum. with a larger opening (oval/rect) and the port injectors I think it will give pretty good gains for a log head when boosted.

 

[drag-200stang]

I would not recommend cutting off the log. That method was started with the early small port heads. The late model heads have larger, funnel ports with large radius port entries very similar to what prostocks are doing now. Cutting off the exhaust ports looks like it would improve flow but the port itself is fairly straight with a gentle curve. Just the flange is at an angle, not the port.

Flow benches don't tell the whole story. The valves are only open for a time once every 2 revolutions. Velocity and port shape are most important.

There is too much work involved to fab up an intake and exhaust that will flow better and still seal and hold up under turbo heat and pressure. I don't feel there is much gain there. You can modify the top of the log for direct mount 2 barrels, tripower, same with throttle valve(s) with some scrap metal, files, hole saws, drills and taps that will work very well.

I also have a fuel injection thread you can look at for more ideas -
http://www.fordsix.com/forum/viewtopic.php?t=27536.