Hey everyone, I'm new to this forum so I apologize in advance if this thread isn't where it belongs. Is it possible to use a 170 cylinder on a 200/250 engine? I heard some people talking about this and they said it can increase performance and raise the compression. Is this possible to do? If so what all would need to be changed?
Yes - all Ford 144 / 170 / 200 / 250 heads are interchangeable. But I would not want to stray away from the 250 head as it has a detachable intake manifold. The 200 and down heads have bad flow through that attached intake. Ford Six .com is a treasure of information on adding HP and torque to the 250.
I believe you're right! IIRC from the Ford Six Manual I had (gave it to a friend), all the heads have intergral intake/heads
True that the compression will go up with the 170's kidney bean shape combustion chamber but the performance will fall with the 170's smaller valves. You could add bigger valves and unshroud the valves to lower the compression. It would be best to use a 200/250 head and take advantage of the larger intake log, larger valves. Try and find a 77-80 200/250 head for more bang for the buck
Why do I remember having a 250 with a separate intake? It would have been a Mustang motor. Were all 250's part of the head? I don't think so. Maybe I'm thinking of the 240's in an F100
Excepting for maybe chamber size, I believe the earlier 250 heads were same as 200... In the later '70s the intake log diameter as well as intake valve were increased in size... I dunno if that applies to 200 or not... The 240 & 300 used in full size & trucks had removable intakes...
There's a lot to say about your question and will elicit many different opinions. If all you did was swap later 250 head with earlier head - yes , the static compression ratio would be raised somewhat . If you take the later head off anyway, you could measure the combustion chambers and have the head milled to a specific target compression ratio . Later heads have larger valves and a little better breathing for carb or valvetrain mods. A lot can be done with the torquey small block sixes and simple mods can make dramatic upgrades to performance. have fun Mav' C8DE 170 in my 63 wagon uses D7DE (77) head cut to @ 48 cc's for @ 9.5:1 static compression ratio . With 2BBl, 5 speed and OEM 3.50:1 rear ratio it's got torque on demand. 170 small chamber DODE (1970) head . . Blueprinted Maverick D6DE Ford small block 250 Six; Shot Peened and Balanced Rods, TRW AMC 258 Pistons, .070 cyl. overbore, Clifford 272H Cam, 1.88 intake valves/1.50 exh with- silicon springs and HD retainers, Ported and Polished chambers and relieved valve shrouds . Fisher custom Harmonic Balancer, Tri-Power / Offy , Modified Holley 1904 glass bowl carbs, Exhaust ¾ siamese port divider, Re-Curved distributor, HEI ignition, Indexed Champion plugs, Glyptal sealed block, Detroit gasket set,. SFI 157 neutral balance-lightened flywheel spinning Centerforce Clutch, T5-Z Cobra 5speed, Short throw Hurst shifter...
Back in the '80s I swapped a '77 250 head on a '75 Granada, if it made any more HP I never felt it(orig was cracked)... Just as lethargic after swap as prior...