difference between a 172 and 197 engine ?

[ian-speedy]

Whats the difference between the 2 engines to give the difference in power

 

[Dan]

Ph1 Or ph2 172 engine??

 

[JackJack]

Intake manifold and some other stuff not sure.

 

[Jonny1*2]

Head is slightly different. As are the cams, inlets and exhaust. I thought bottom end was the same apart from the fly side to accommodate the new box

 

[ian-speedy]

i'd like to get my car up to 230-240 hp so was wondering how they had more power to start with , I'm going headwork , cams , pistons and rods and throttle bodies , my car seems to go well now so would be awesome with another 30-40hp

 

[Chip-mk1]

197 has different port job on the head, inlets are very different. It also has pistons that have far less volume above them, partly to increase compession and partly to change the shape of the chamber, they actually have a bigger chamber volume than the 172 head but not by as much as the pistons intrude so net effect is still more compression.
Cams are hotter and are also on a much more variable cam timing setup than the basic 2 position one on the 172, IIRC its 45 degrees and fully variable so you can get away with a hotter cam and still drive nice lower down.

Im not convinced any of that is going to be very relevant to you in the context of an ITB car for track use with high comp pistons and hot cams etc though TBH, so I dont really think the 197 is particuarly a better starting point anyway.

 

[ian-speedy]

thanks , that's the info I was looking for.

Going back to my engine , which is a sealed race engine , I had the top part of the inlet manifold off to change the plugs the other week , and the inlet ports looked like they were CNC machined , all looking the same , is this normal for the race cars ?

 

[leeds_182]

The 172 engine is relatively economical and the 197 is like running a v8!

 

[mark123]

All 172/182 heads have CNC machined ports from the factory.

 

[not normal dan]

The 172 engine is relatively economical and the 197 is like running a v8!

Your right there my old 172 was always around 35mpg +. You struggle to get 30mpg in me new 197

 

[ian-speedy]

The 172 engine is relatively economical and the 197 is like running a v8!

I have an M3 V8 , and I don't think any other car drinks like it ! the way I drive it , it does about 12 to the gallon lol

All 172/182 heads have CNC machined ports from the factory.

Thanks , didn't know that

 

[Jonny1*2]

thanks , that's the info I was looking for.

Going back to my engine , which is a sealed race engine , I had the top part of the inlet manifold off to change the plugs the other week , and the inlet ports looked like they were CNC machined , all looking the same , is this normal for the race cars ?

If they were smooth they might have been matched. Head porting will make a difference. Not sure whether you have a ph1 engine in there.
If it was me, I'd get the block bored to 83mm and go for a fully forged bottom end, high comp, with uprated valves/springs/cams, uprated exhaust manifold, with ITBs just to help out give Matt @ TDF a bell and he will sort you a package out. Depends what you budget is Ian