Stroke Differences ?

speedy57tub · Post by **speedy57tub** » Mon Jan 06, 2003 10:31 am

My friend asked me the following question and I told him I would ask the forum to get some feedback. He has a VW based Speedster car (like mine except it is flared and has all wheel Porsche disc brakes). He likes my 2110-cc but he wants to check into other configurations (I guess he wants to be different). His question is the following:

-What are the performance differences between the 2110-cc (82-mm x 90.5-mm), 2176-cc (78.4-mm x 94-mm), and 2017-cc (78.4-mm x 90.5-mm) engine configurations? I could only comment on the 82-mm stroke since I have yet to build a 78.4 stroke engine. He plans to use a new case, “ported and polished” 044 42-mm x 37-mm heads with dual springs, counterweighted crank, H-beam or I-beam rods (what rod length can be used to maintain “stock size” engine width and with the least amount of clearancing?), dual 44 IDFs, 122/125 Webcam cam and lifters, stock rockers on solid shafts, 911 adjusters, Aircooled.net Al pushrods or chromoly, 30-mm oil pump, slightly lightened 8-dowelled flywheel (for fast road car what weight is recommended?), 9.25-9.5 C/R, full assembly balance, Stage-1 or 2 KEP clutch, chromoly gland nut, 1-5/8” header and performance muffler with 1-5/8” heater boxes, and German parts throughout.

What he wants is a “snappy”, “sporty”, good revving, all around performer for his lightweight replica. He does not know what cooling system he wants, but he might go with my 911-shroud design. He is the kind of guy who likes to be different for the sakes of being difference! Please let me know what you guys have tried and like.

As for me, I'll use my 2110-cc until I can go to a Type 4 whereas my bud wants to use his Type 1 parts. Everyone is definitely different but that is what makes us interesting!

------------------
Thanks, speedy57tub
(Speedying around and about "Viva Las Vegas")

[This message has been edited by speedy57tub (edited 01-06-2003).]

speedy57tub · Post by **speedy57tub** » Mon Jan 06, 2003 2:18 pm

Anyone?

------------------
Thanks, speedy57tub
(Speedying around and about "Viva Las Vegas")

type IV mainframe · Post by **type IV mainframe** » Mon Jan 06, 2003 3:28 pm

from what you've listed above, sounds like a great motor.

for reliability sake, i personally would lower the compression slightly. i ran a 1776 at 9.6 c/r and found it ran a little hot for my daily driver needs. Being in a speedster cooling may be easier to take care of. 14lb flywheel worked great in my 1500lb (<--estimate) bug.

speedy57tub · Post by **speedy57tub** » Mon Jan 06, 2003 4:34 pm

type IV mainframe, which configuration? 2110-cc, 2176-cc, 0r 2017?

HELP, I am trying to steer my friend away from going the Subaru H20 route! Like I said, he likes to be different!

------------------
Thanks, speedy57tub
(Speedying around and about "Viva Las Vegas")

[This message has been edited by speedy57tub (edited 01-06-2003).]

JC-ATL · Post by **JC-ATL** » Tue Jan 07, 2003 6:36 am

In my opinion, you're not likely to notice a hell of a lot of difference between any of the three engines you've listed, as the variations in stroke and bore aren't all that great, all other factors being equal.

Some folks don't like 94s, but I have no issues with them.

Your 82mm stroke is going to require a lot more clearancing work.

Build difficulty is going to be about the same between the 2176cc and the 2017cc, so why not go for the displacement?

I have noticed that you've not mentioned the 2276 combination, which I understand will not be all that snappy, though it can make tremendous power.

If he really wants to be different, he should run a T4, like a 2270.

speedy57tub · Post by **speedy57tub** » Tue Jan 07, 2003 7:59 am

That is what I told him. If I could go back a year, I would of gone the "Rat" Type IV route but I went with the Type I 2110-cc. My friend has the chance of going for the Type IV but he is not convinced (stuborn) even though he is not technical capable of understanding powerplants. He has the money and can do it on a heartbeat but he always wants to be different. He currently has a Subaru engine in his sandrail and is now wondering about putting one on his Speedster replica (Yuk, total platform desecration!). If I was the car, I would experience donor rejection! I even told him to consider a RAT engine and showed him Aircooled Technology's (Jake's) site but he says "I just do not know, what is that Type 1 with the 82 or 78.4 stroke again?". I mean, he is a nice guy and, afterall, he does let me play with his toys (he makes good money and much, much more than me!). Anyways, he has his heart set on a 78.4-mm or 82-mm stroke configuration. I'll keep working on him to go for a RAT Type IV (like I personally would of liked to).

------------------
Thanks, speedy57tub
(Speedying around and about "Viva Las Vegas")

[This message has been edited by speedy57tub (edited 01-07-2003).]

dbnbde · Post by **dbnbde** » Tue Jan 07, 2003 1:33 pm

check out cal-look.com and go to the tech section and onto Fast Engines under the tech menu. There is some info there for you, but I agree, if your going to do it, DO IT, and go for the 82mm. Have fun.

------------------
70' SLAMMED bug, finally, yeah!!!oops...too low doubt!
75' vw bus $500 rust bucket/winter rig/camp rig. Starts every time. Best 500 i've ever spent!:)
ex owner of 82 BMW 633csi :*(
www.geocities.com/dbnbde

JC-ATL · Post by **JC-ATL** » Tue Jan 07, 2003 1:41 pm

If he's excited about a T1, send him to Jake, too. I've driven a few of Jake's big old monster T1's, as well as some of the smaller stuff, and that would be an interesting idea as well.

You may want to see if Jake's 2332 from his own car is still available. If I had a spare 5 grand, I'd own it.

Empified · Post by **Empified** » Thu Feb 06, 2003 8:28 am

I have noticed that you've not mentioned the 2276 combination, which I understand will not be all that snappy, though it can make tremendous power.

With short rods a 2276 can be plenty peppy. It's all in the way you build a motor.

speedy57tub
Tell your friend if he's going to stroke it then by all means STROKE IT!!!!! 82mm crank minimum. If he wants to run a little cooler then stay with the 90.5 pistons. Otherwise the 94's are great to just a little hotter. Being that the subaru engine is heavier than a VW engine, he'll have to produce more hp and torque to compensate. Empified..............

------------------
If you have to ask, you can't afford it.
No fat chicks allowed my bug will scrape!!!!

speedy57tub · Post by **speedy57tub** » Fri Feb 07, 2003 7:39 am

Thanks for all of the replies! I was trying to get a difference between the 82-mm and 78.4-mm strokes.

------------------
Thanks, speedy57tub
(Speedying around and about "Viva Las Vegas")

dstar5000 · Post by **dstar5000** » Fri Feb 07, 2003 9:36 am

Like my GF sez:
If you're gonna stroke it, stroke it as LONG as you CAN!!

Don

------------------
78 Westy 2.0l
71 Bradley GT 1641cc(soon to be SOLD)

"The greatest pleasure in life is doing what people say you cannot do".
Walter Bagehot

andreas5bmw · Post by **andreas5bmw** » Fri Feb 07, 2003 6:26 pm

In theory the 78.4 crank should rev faster because it's a smaller crank.But that's only theory right.Also this is from knowledge i've built 2 identical motors except buy size and heads were the only differt.The 2165 had a k8,and 44x37 valve it made 192hp.The 2275 had K8 cam,42x37 valve it made 188hp.Compression was the same on each motor.The 2165 did have to work alot harder to make that power.