1600 - 2000 crankshaft

[Snowy]

I cannot remember who was asking but here is a picture of a 1600 and 2000 crank next to each other.

You can clearly see the different counter weights. 

 

[Trooker]

I’ve read about the difference over the years but it’s really great to see it like this. 

Are you planning to build a high revving engine with the 1600 crankshaft? 

[Snowy]

2 hours ago, Trooker said:

I’ve read about the difference over the years but it’s really great to see it like this. 

Are you planning to build a high revving engine with the 1600 crankshaft? 

Not high revving, but the 1600 crank causes less vibrations at higher rpm.

It's installed along with 3 piston now. One will have to wait until tw thorntons opens again Monday as one of the oil control rings supplied is the wrong size.

[Trooker]

Ooops, you’re clearly making good  progress with it though. 
 

[Snowy]

On 15/08/2021 at 14:32, Trooker said:

Ooops, you’re clearly making good  progress with it though. 
 

All installed now. Just waiting for my timing cover now then the bottom end can be finished.

Cam is being sent off to Newman cams. Just cannot decide if I want to go with a 2.4 head or 2L head.

Thanks

[Jessopia74]

You will lose torque with the 2.4 head, and as you are not going for rpm bhp then it's not for you.

[Snowy]

14 hours ago, Jessopia74 said:

You will lose torque with the 2.4 head, and as you are not going for rpm bhp then it's not for you.

Can you quote your source for this information?

I've been doing a lot of research and from what I'm reading, and talking to guys in the Netherlands doing this, I will not loose torque. 

The 2.2 head seems to be the weak link, especially the exhaust ports that don't flow as well as the 2.0, but the 2.4 rectified that issue.

[Jessopia74]

5 hours ago, Snowy said:

Can you quote your source for this information?

I've been doing a lot of research and from what I'm reading, and talking to guys in the Netherlands doing this, I will not loose torque. 

The 2.2 head seems to be the weak link, especially the exhaust ports that don't flow as well as the 2.0, but the 2.4 rectified that issue.

It's to do with port velocity.  Plenty on the subject if you google it mate. 

[lamchop77]

I’ve done quite a bit of research into this over the years but there is some dud information out there. 2.2 heads are pretty good the flow just needs working on with the exhaust port, I think it gets narrow around the valve guide area so it needs opening uP a bit in that area, fit 46/42 rec valves and the flow will increase more. The raised port design works well when you get the motors revving, think they were developed from the “Sweden heads” that were being done. I was in touch with a guy that had his heads tested on a flow bench, the results were basically a 2.2 std head basically flows the same as a fully ported 2.0. I can’t remember exactly but there is an issue with the 2.4 heads in that the port shape isn’t quite right….I can’t recall exactly and I think there was something to do with the exhaust valve temperature s getting Hogg with them as well . I went with the 2.2 head because of that fact. You definitely need to be using a big lift cam as well, around the 14mm mark minimum. If you’re not getting that just stick with the 2.0 clean the ports up a bit and use the 45mm inlet valves from the 2.4 head… they’ll need unshrouding as well in the combustion chamber. That should give you a bit of a pokey motor!!

Hth

Chris

[Jessopia74]

Absolutely Chris, what you are describing is an issue of increasing cylinder fill.

You can combat fill restriction as you say with bigger cam and valves and still retain the higher velocity, but if that velocity drops too much as low rpm then your low rpm fill suffers at the cost of torque. This is why some clever engines use dual ports (proper head feed heads) or butterfly on the inlet tracks to keep the speed up at low rpm, where the volume is not an issue. Should you have been going to increase you bhp and red line, then the 2,4 head flow would be a great thing to have. But as your not and want it low down, the 2.0 head is better.

 

[Snowy]

7 hours ago, Jessopia74 said:

It's to do with port velocity.  Plenty on the subject if you google it mate. 

I have.....and I'm actually talking to people who build these engines with the parts mentioned. Proven results, not just here say.....

[Jessopia74]

54 minutes ago, Snowy said:

I have.....and I'm actually talking to people who build these engines with the parts mentioned. Proven results, not just here say.....

😉  Let's just say I have spent a ridiculous amount hours with die grinders and home made flow meters on CIH heads. I spent hours up at a place in Malton who rallied Mantas in the 80s. 
if you don't like my answers, then please continue and expect disappointment. It's shame that you have obviously already made your mind up, so don't insult my knowledge or waste my time.

[lamchop77]

My info has been gleaned from guys who race, I’ve toyed around with a 2.0 cih motor and managed to get nearly 160bhp off a virtually standard ending with 40’s and a 234 Kent cam no other trick parts. Similar job on a 2.2, std pistons, bottom end, good head and cam, carbs and had a motor that was knocking on the door of 180bhp. Used to hold its own grassing against full race red tops on throttle bodies. I’m not going to say I’m an expert on this but what I’ve done on the cheap has worked and worked well. Some of the guys I’ve conversed with have serious engines revving 8500-9000 reliably with high power so they know their stuff.

Hope you get the desired results, these old boat anchors are such a cool engine!!

 

[Snowy]

9 hours ago, Jessopia74 said:

😉  Let's just say I have spent a ridiculous amount hours with die grinders and home made flow meters on CIH heads. I spent hours up at a place in Malton who rallied Mantas in the 80s. 
if you don't like my answers, then please continue and expect disappointment. It's shame that you have obviously already made your mind up, so don't insult my knowledge or waste my time.

I'm taking advice from people in europe who are building these engines now. With rolling road figures to back up their statements. So yes I will wait for my disappointment.  Thanks 

Edited August 25, 2021 by Snowy

[Jonathan Pounsett]

It’s never going to be an exact science with so many options at play. The number of permutations is mind boggling. Good luck with whatever you do @Snowy.

These forums are a great place to learn, sometimes from other peoples mistakes. Bolting a variety of parts together is always going to be “Trial and Error” after all. 
 

So long as all the clearances checkout it shouldn’t go BANG! 🤞

PS. (And disclaimer) I don’t know what I’m talking about. 

[Jessopia74]

5 hours ago, Snowy said:

I'm taking advice from people in europe who are building these engines now. With rolling road figures to back up their statements. So yes I will wait for my disappointment.  Thanks 

So why you asking all us here who obviously know nothing? You seem like you are just here to troll tbh.