Considering a 2.2

[pnishr]

Well, my crank is crap, and I'm looking at building a 2.2 I can do this a couple of ways.

A. 2.0 block, 94mm crank, 150mm rods, stroker pistons, and shave 3mm of deck.
Rod Ratio: 1.596

B. 2.4 block, 94mm crank, 156mm rods, stroker pistons, and shave 3mm of deck.
Rod Ratio: 1.660

C. 2.4 block, 94mm crank, 159mm rods, stroker pistons.
Rod Ratio: 1.691

I've looked around for other engines rods I could use, but VW 2.0 is the closest, but the main bore is WAY too big, so the 159mm rods would be custom.

Anybody know how much custom rods would be?

I'm leaning away from option A, as you might as well do a 2.4 long-rod with that shitty rod-ratio. I'm looking to build an engine with a lot of room for RPM as top-speed is a goal for me (so don't start with the "you don't have to rev it as high because it makes more power lower" crap. I know, but engine speed X gear ratios = speed)

B and C are where I'm leaning. C would be best, but that may depend on the price of the rods. I'll also be building a long-rod 2.4 for other purposes, and to test the differences. And, I'd hate to have somebody shave THREE MILLIMETERS!!! off of a perfectly good deck.

So, "WHY?" you ask... well, with option C, you're talking about a 2.235 displacement engine (12% more displacement) and a rod ratio that is only .7% lower than the 2.0, for higher RPMs.

Any suggestions on where to go for the rods? Estimates on prices? Nay-saying. I know some have taken their 2.3-2.4s up to 9000+ rpms, but I don't know how willing I'd be to do it... maybe I've just read too much negativity about it.

[Jake30]

I would give Marco@Magnus a call about the rods. I know he has built a few 2.2L engines and I know he deals with some custom sized rods. The Magnus I beam rods are available in 150/156/162 and I believe he custom orders them as well. They are from Australia so it might take a little while.

Either that or call the manufacturer of the rod you want and talk to them about it. Usually there is a "custom order" fee, but I doubt it could be that much.

Are you set on building a 2.2? If you are looking for higher RPM and and easy build, why not a 2.1 destroked? I am guessing you are going to be building this engine, so its really up to you on how you feel but if I was to put together a engine for higher RPM and top speed, I would probably end up with a high compression 2.1L and I would feel comfortable taking it to 12000 RPMs. Just my opinion, but if you're looking for RPM, this might be a good option.

[pnishr]

Well, I had considered a 2.1 but... the 2.2 would be another 5% displacement. AND, I'm not trying to rev to the moon or anything. Actually, I don't plan on needing anything more than 9-9500rpm, BUT, I'd like to be able to trust that for a few seconds, as opposed to how unsure I'd be taking the 2.4 that high. for more than a blip.

I hadn't talked to Marco about it, but I've downloaded and filled out the forms for custom rods for Pauter and Carillo. I just haven't sent them in because I wanted a general price idea before I make them quote me and i can't spend it right now.

[kiggly]

Shaving 3mm off the deck is just begging for a head gasket that will not seal. Make up the height with the rods or the pistons.

Kevin

[pnishr]

Thank you, sir. Yeah, I think I'd just feel bad about it anyway... destroying a block like that...

[DoyoFCT]

how did you come up with option C? i thought you could use a longer rod than that, if you used stroker pistons and a 94mm crank.

[pnishr]

Because the crank size is given as the total distance traveled up and down, not as height from centerline (main journal) The actual change in height the piston moves up (which is what we need to know) is only HALF the difference of the cranks.

A 2.4L block is only 6mm taller than a 2.0. this is because the difference in height between the two is only 6mm all around. In other words, if you put the 100mm crank, and 88mm crank on the same axis, you would only see 6mm of the 100mm crank showing from behind the 88mm crank. BUT, the 6mm difference is around all sides.

I guess what i'm saying is that the RADIUS of the crank (not the diameter- which is how they are measured) is what's important here, because that is the amount that actually changes how far the piston move up (towards the deck)

Since the 94mm crank is only 6mm smaller, the radius is changed by 3mm.

Nobody explained this to me. It's one of those REALLY easy things, that's REALLY easy to overlook. It took me a couple of days thinking about all of the combinations and how they work. Overanalyzing. Then, as I was pooing one night, it hit me like a ton of bricks. The other 6mm difference that a 100mm crank moves the piston is DOWN.

I'm not sure if that really explained it well. Maybe I'll do a Paint.document to illustrate.

This is also why when converting a 2.0 block to a 2.4, you have to use -6mm height pistons. because the -6 makes up for the 12mm crank diff. (which is only 6mm dif on either side- aka up and down)

[pnishr]

Originally Posted by DoyoFCT

how did you come up with option C? i thought you could use a longer rod than that, if you used stroker pistons and a 94mm crank.

Oh, and perhaps you're thinking of a 2.1. which uses an 88mm crank (3mm difference in UPWARD travel) and a 162mm rod (3mm shorter than my 159mm 2.2L option)

[DoyoFCT]

yea i see now, i just thought it was ok to make up the length differences evenly between rods/pistons and the crank. Ive got a g4cs block that im planning on using for a build like you mentioned as option C. but i havent started looking into all of the specifics just yet.
im going to order custom rods/pistons when i do though, and purchase the eagle crank.

thanks for the picture explanation.

[pnishr]

Originally Posted by DoyoFCT

yea i see now, i just thought it was ok to make up the length differences evenly between rods/pistons and the crank.

It is. You could do it all with rod or piston, but that depends on how much more room there is to change the pin height on the piston, which I don't know. If I wanted, I could use a stock pin piston, and use a 153mm rod (which would still be custom) But to achieve a better rod ratio, I'm using the "stroker" piston with the pin moved up 6mm. If I had custom pistons made, and they could move the wrist pin up another 3mm, I could use the 162mm rods, and have a ratio better than that of the 2.0. I'm glad you got my explanation. Seriously, I was ready to kill myself before it hit me that the crank RADIUS was what mattered. I felt like such an idiot. Oh well. good luck with your build.

[DoyoFCT]

yea it would probably be cheaper to just buy off the shelf stroker pistons, and have the rods custom. I was kind of hoping the 162's would have worked because of the rod ratio gains but i think even with the 159's it's a very good ratio compared to the other stroker combos

[pnishr]

Actually, after that post I made about the wrist pin being moved, I've started looking at custom pistons. I think the price will be about the same for custom pistons vs. custom rods. And the 162 would be pretty cool. I'm just not sure if there's enough room to move the pin any higher up. I'll keep you up to date on here with what I find. 1.72xx rod ratio would be pretty sweet.

[DoyoFCT]

i forgot that the pistons aren't exactly off the shelf since the bore of the 2.4 is 86.5 - 87 depending on the overbore. I talked to manley and they wont do the rod unless there's a min. order of 10+ so im going to call a few other places. but i guess let me know what you dig up on the pistons, im going to call Ross tomorrow. since manley already makes the 162mm rod i was really wanting to go with that but hopefully i can find someone who will build the rod without a crazy cost/min. order.

the price to be different i guess...

[Jake30]

Custom pistons will be cheaper than rods. You can get a set of custom pistons for 5-700 depending on the options you add.

My pistons were $750 with just about every option I could add. A lot of which you would not need.

When going that route... Find out what size wrist pin the rods will accept. If you can get a larger pin, I would suggest it. Marco sells a 162mm rod with a 22mm wrist pin if I remember correctly.

Nice diagram/write up. A lot of people over look that info.

[Lunch_Box]

I am about to put option C into my car. I have a sete of Ross pistons, Eagle 94mm crank, and a set of custom Pauter 159mm rods. The rods were $750 and about a 2 month wait. Everything is at the machine shop getting balanced but I will let you know how it goes.

[pnishr]

Bastard!!

So, Pauter should maybe even have some already blueprinted then...

Well, I'm gonna check the piston option out first. Now that it was brought up, I might as well check into it. since it would be a (VERY) slightly better combo. Thanks for letting me know about your setup. I can't wait to see how it does.

Anybody with in-depth knowledge (or perhaps an extra "stroker" piston laying around) have any idea whether there's enough room to move the pin up another 3mm...?

[wortdog]

Yes, moving the pin up more is possible, but it does have some downsides. I'm not sure about some of the other pistons, but moving the pin up 3mm on my 2.3 Ross pistons would put the pin almost into the 2nd ringland. Both the top and bottom ringlands would have to be moved up towards the top of the piston at least 1mm, and you'd lose a tiny bit of the top of piston to 1st ringland spacing that is crucial for pistons to live in high boost/temperature environments.

In a nutshell, the piston would work fine, it would just be a little more sensitive to heat/detonation.

Going off pictures of the Mahle stroker pistons, it looks like they already have the ringlands a bit closer to the top, so maybe the Ross pistons are just overkill.

[pnishr]

Thank you for the input. I'll take a look at that, and the differences between the Mahle and Ross ringlands

[Jon Lane]

Originally Posted by wortdog

Going off pictures of the Mahle stroker pistons, it looks like they already have the ringlands a bit closer to the top, so maybe the Ross pistons are just overkill.

Do you have a link and/or part number?

[NewTurboTuner]

I was comming to post about a 2.2L and ...wow I found this. Cool!

So I see you've thought alot about HOW to make a 2.2L ...could you explain more about WHY you want a 2.2L, and its benefits?

I'm doing an engine build over the winter and I haven't been able to decided what I want to build. For the longest time I wanted to build a 2.1L for Hi Rev's. Then I decided a nice 2L would be good, because it will rev high, and its proven to be reliable. And Lately I've been going back to the Idea of building a 2.4L because I now plan to install a GT40 or GT42. And a few weeks ago I came across the 2.2L motor which I'm highly interested in, but can't find much info about it and people who actually have one.

I hear it revs like a 2L, and has tourqe like a 2.4L .....sounds NIIIIIIIIIIIICE!
...can anybody tell me more about it, or point me in the direction where I can find out more about it?

Damn I wish I could get into NABR

[wortdog]