Mod-Log Turbo'd 250 Build

JGTurbo

Well-known member
It's coming together at Karl's machine shop in Klamath Falls. I'll post some more pictures soon.
 
Yeah, the manifold is fabricated. It just needs to be flattened and coated. I'm on my way to the machine shop right now to do some more work on it. I will try to get some more recent pictures up, as well as numbers from the flowbench. (I did a little flowbench testing the other day, and the numbers are looking really good!)
 
Here are some specs:

- Late 70's 250 block, crank, and head
- Forged 250 rods
- .030 Forged pistons (old TRW's I think, but they were new in box)
- SpeedPro rings
- Custom grind from Comp (mild duration, aggressive lobes, turbo LSA)
- Custom machined log head (flow chart coming soon)
- Fabricated intake and exhaust manifolds
- Crower single springs
- 1.80" intake, 1.5" exhaust stainless valves
- Garrett T3/T4 Hybrid
- Holley 350 2 barrel blow through
- Front mount intercooler
-
- Hoping for over 300hp and LOTS of Torque!
 
It is milled off perpendicular to the deck.
The flow is at 28" H2O.
Pardon the welds... They will get cleaned up before it is coated.

 
Thanks, I'll update that post. I really couldn't remember what sizes you ordered. Yeah, the head flow kind of surprised me. Quite an improvement from the stock intake (119cfm@.400) and exhaust (98cfm@.400). It matches the aluminum head for flow up to .300 on the intake. The exhaust actually out-flows than the aluminum head up to .300. Probably because the ports ended up being a lot shorter. I'm guessing the aluminum head does better than ours at .400 and over because of the reduced shrouding at higher lifts.
 
The test I ran the next day was more accurate I think and it showed right about 160 cfm. I didn't bother testing it at .500" because our cam never lifts the valves that high. I think the flow at .400" and below is more important anyway.
 
pics were too big, so i changed them to thumbnails, if you want to see big ones please click them!
 
Thanks for shrinking those pics.
The runners are just mild steel mandrel bends from summit. The exhaust manifold is square tubing that we formed a taper out of. The flange was supposedly hardened armor plating from some sort of battleship (never know what you'll find laying around the shop at OIT).
The head is now torqued down and the bolt holes in the manifold are relieved (so the bolt heads clear the welds). Tomorrow I think I'll cut the bolts (all 32 of them!) to length. After that, the manifold will just need to be coated and mounted!
I'm planning on building a support to go from the turbo flange to the block. Turbos are pretty heavy and I don't want to put any unnecessary stress on the manifold bolts.
 
Well, the intake manifold is flattened and painted. I forgot my camera today, so no new pictures to post. All the intake bolts are cut to length. I think I'll wait to mount the intake manifold until the rest of the engine is assembled and painted.
 
The intake is on! I decided to put it on today even though the rest of the engine isn't together yet.

I'm not sure how to make the images any smaller. Asa, maybe you could shrink them again?
Thanks


 
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