Topic: 28ci with 25 head

[nhoule]

I, I have a 25ci stock. I want to know if there should be a big difference if I buy a 28ci and then I put the 25ci head on it... I saw a fresh rebuilt 28ci for 250 bucks ...

[guitarplayer]

if you put the 25ci head on the 28 it will boost compression.

[nhoule]

Of course, but is this make a real difference ?

[swbeebe]

From what I gather, the gain in compression also has a loss of flow. I believe if built right you will actually have better performance using the 28 head. (Because of flow and larger volume) Once you start increasing compression you might also be looking at a different starter to handle the load. Some people think the 25 head will make a difference, but I think it would depend on how built the engine is. If fully built, I would stay with the 28 head. I'm sure others will chime in on this subject... But whats a few bolts and a head gasket? Try and see what works for you.

[guitarplayer]

From what I gather, the gain in compression also has a loss of flow. I believe if built right you will actually have better performance using the 28 head. (Because of flow and larger volume) Once you start increasing compression you might also be looking at a different starter to handle the load. Some people think the 25 head will make a difference, but I think it would depend on how built the engine is. If fully built, I would stay with the 28 head. I'm sure others will chime in on this subject... But whats a few bolts and a head gasket? Try and see what works for you.

very true. flatheads need more flow than high compression. but it's worth experimenting with. i never have tried it myself, been wanting to though.

[nhoule]

For mine I just added a big cone filter and I straight piped the motor... I can't add more air into it... And should I stay with my 25ci ? Or a 28ci make all the difference ? I don't want to spend 1500 $ !!!

[Rooster]

A fresh 28 will be a big difference over that 25.

[guitarplayer]

i'd say the 28, more can be done with it. but i have alot of plans for the 25.

little off topic, but if anyone is interested in my 25 project, check this video out for my plans, i say plans because i need to make some parts for all to work (as soon as i start machining which i hope to this summer)... and i did make one mistake in the video, i said the valves are the same in the 2 engines, they are not the same...
http://www.youtube.com/watch?v=H1kiFqCDCh0

[amcchevy1]

for a 28" engine, the 25" head will work great. once you start modifying the engine with a cam and such you would want to go to the 28" head.