Hey Guys, New Here, Question On Stroke

[Guest]

Hey guys. Im new here, but an old man at the Turboford 2.3 site. I had 5 or so 2.3 turbo cars, and decided to move on to something a little more interesting.

I have a 62 Falcon, and when I did the head gasket about 4 k ago, I noticed honing lines in the bore (recent previous rebuild, YEAH!). Also, since the head ended up being cracked, I put a 200 head my father had laying around. I measured the bore, and that said it was either a 170 or 200, I measured the stroke (3.5 approx.) and I never ended up finding out if that was the stroke of the 170 or the 200.

One main reason I ask is because the original head had the same sized valves as the 200 head I replaced it with. I know the 144 has smaller valves, as I tried to use a 144 head on the replacement, but I chose not to because of the valve size. The stroke on the 144 was considerably smaller (I think 2.5 or 2.75).

I guess to the root question...if the stroke is 3.5, does that designate it as a 170, or a 200?

Thanks for your help. Joe

 

[CZLN6]

Howdy back Joe:

Bore and Stroke lengths-
144= 3.5" x 2.5"
170= 3.5" x 2.94"
200= 3.68" x 3.126"
250= 3.68" x 3.91"

Early 170s had smaller valves too. '61 - '63 170s had 1.52" intake and 1.26" exhaust vave sizes. Later had the same size valves as 200 till about '75, at 1.649" intake and 1.38" exhaust.

'78 and Later heads have the largest intake valves, hardened seats, a 1.75" carb hole and larger intake tract volume. But they also have a larger combustion chamber volume at about 62 cc, as compared to the earlier, smaller chambers at about 52 cc.

If your engine has a stoke of 3.5" you have a very unusual engine. Did you measure the piston stroke or the cylinder height to the top of the block? Deck height on these engines can be as much as .025".

How about counting the freeze plugs under the exhaust maniflod on the passenger side. 3 = 170, 5 = 200.

Adios, David

 

[addo]

Argentinian motor? 221 has a 3.46 stroke.

 

[Guest]

I measured from the top of the piston to the top of the deck, at tdc on that cylinder. I got 3.5 or give or take 1/100th or so. Its got the large valves off of a 200 head I put on, as the original head I got it with had the same size. I luckilly found a head with new guides and sliding tight Ford new valves. Runs great, burns and blows no oil, I just put in umbrellas, since I plan to pull the head in a couple of years when the HG blows, so I can put on my Offy Tri Carb.

I got the 144 head from a friend, the valves are very tiny, comparitively to the 200 head (I think the casting for the 200 was from the early 70's). I got lucky in finding the 200 head, as my fathers machine shop has been in the process of moving, and everything is scattered. It was sitting practically right in front of me, and I id'ed it instantly. It had a 4 bl intake, which I switched to my 2 bl by making an adaptor plate. I could always bore the intake inlet out if I want to switch to 4 bl, but Im really on a gas saving ideology right now. Plus, setting up a choke, linkage and everything would be a pain.

Your suggestion on deck height may be a reason. I doubt, though, that its a South American block. This car sat in a barn in Indiana for most of its life, and has 77k on it, I think I put 5k or so on it so far. It still has the old oil change plastic thing on the drivers door, with the little slips of oil changes in it from 1963, when it had 27k on it. I found that pretty neat.

Ok, not to gett too off-topic. I think I had my question answered...its a 170, approx 3.5 stroke. Ill check the freeze plug idea when I get over my bronchitis and decide to make it out to the garage.

Thanks,

Joe