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> Cost to go to 78mm stroke??, anyone have some numbers???
Randal
post Dec 13 2004, 08:56 PM
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QUOTE
Here is a picture of the 78mm crank installed


Now that is beautiful! Can I borrow it for a few events?
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Mueller
post Dec 13 2004, 11:21 PM
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QUOTE(Bleyseng @ Dec 13 2004, 06:33 PM)
damn Mike, you gonna build a 102x78 monster for your daily driver 914? Kewl!

Geoff

I wish.....nah, I'm being cheap and sticking with the 94mm bore...if I go with the hp per cubic centimeter of Jakes 2270 that uses sorta stock 2.0 heads, I should have 150 hp at the wheels....I hope so !!!!!

Watch out Trekkor, the /4's shall rule the auto-x field, LOL
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Jake Raby
post Dec 13 2004, 11:37 PM
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Mike, thats gonna be tough..

You could change the arrangements with Charles and make it into a 96mm bore and a 2316 (80 crank) and get around 150 at the wheels..

The 80mm crank done my way is EASIER to install than a 78!

That 2316 combo is NASTY and still very drivable! Torque from hell and it pulls like mad with instantaneous throttle response!
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Mueller
post Dec 13 2004, 11:59 PM
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tempting, but I'm going to have to draw the line someplace..."feature creep" is going end up costing too much money (IMG:style_emoticons/default/smile.gif)


is 130hp at the wheels asking too much with the current 94x78 combo? Is the 94x80 combo something that can be done? If so, additional cost above and beyond the 78mm stroke.....
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Bleyseng
post Dec 14 2004, 12:07 AM
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Why keep increasing the stroke? Why not increase the displacement to 102mm? Why not just do a 102x71mm engine?
Geoff
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Mueller
post Dec 14 2004, 12:17 AM
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QUOTE(Bleyseng @ Dec 13 2004, 11:07 PM)
Why keep increasing the stroke? Why not increase the displacement to 102mm? Why not just do a 102x71mm engine?
Geoff

I believe these motors are more effecient with longer stroke combos..the cylinder is so big and with small valves that the motor needs the extra time for the stroke to go all the way down to really fill up the cylinder with air and fuel...something like that if that makes any sense (IMG:style_emoticons/default/smile.gif)

the cost of going to 102's gets expensive real fast, the pistons cost more and I'm pretty darn sure at that level "real" head work is required......my heads are already done and most of the engine is paid for....or so I hope (IMG:style_emoticons/default/wacko.gif)
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Aaron Cox
post Dec 14 2004, 12:23 AM
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so go big stroke and an extra 2mm bore....cost less to bore out stock cyls....then it does for 102 nikkies....

you should start a donate paypal thing like i did!

im up to 7 cents..!!!! (IMG:style_emoticons/default/laugh.gif)
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Mueller
post Dec 14 2004, 12:28 AM
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QUOTE(Aaron Cox @ Dec 13 2004, 11:23 PM)
so go big stroke and an extra 2mm bore....cost less to bore out stock cyls....then it does for 102 nikkies....

you should start a donate paypal thing like i did!

im up to 7 cents..!!!! (IMG:style_emoticons/default/laugh.gif)

I want the Nickies !!!!!!

I'm sure this won't be my last Type IV motor....I'll learn from this one and wait for Jake to keep on devoloping parts and combos..........
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Bleyseng
post Dec 14 2004, 12:46 AM
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Cost the same for little Nikkies as it does for big Nikkies........

Geoff (IMG:style_emoticons/default/biggrin.gif)
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crash914
post Dec 14 2004, 06:52 AM
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Mike, go with Jake on this one.....

I did it my self and had to redo just about everything....80mm crank...scat rods, I ground them down then ended up sending them to Jake, they work much better now...bought a reduced base circle cam...ended up getting another from Jake this time as it was even smaller and fit better...

His prices are what I spent not buying from him....then I re-bought from Jake.....do it once the right way...

Can you say 103mm Nickies..... (IMG:style_emoticons/default/wub.gif) I have to say though, the case work is not too bad up to 80mm..

Go for it...herb
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DNHunt
post Dec 14 2004, 07:48 AM
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Mike Why 94mm and not 96nn. I understand your idea about the longer stroke. But 96 is a real tried and true bore. Jakes done a bunch of these and he's said he likes 96 X 78. Get Charles to change to 96

Building the kit Jake put together was really fun. If I ever win the lottery I think I'd just stay home and assemble Jakes kits.

There are certainly things to work out. Valve train geometry is tedious. Deck height is kind of tedious too as I kept rechecking it. It sure helped having Jake looking over my shoulder so to speak. The numbers never come out just exactly the same so I could bounce them off him and he let me know if they were in the ball park. It kind of reminded me of labs. There was always a little variability in the numbers.

Plan on fabbing or buying some tools. You'll need to CC your heads, be able to clamp your cylinders to the case and measure deck height, and measure valve opening and closing for valve train geometry.

Dave

Dave
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Jake Raby
post Dec 14 2004, 08:56 AM
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All those special tools will be for sale soon- Made just for the Type IV engine!

Hell with the kits you'll have a choice to buy or rent a COMPLETE tool kit to do the job yourself! I'm talkin every tool!

As far as the 71x102 goes I have several combos for it, and have built them, BUT There is NOTHING like stroke!

That stock 2.0 rod journal should be avoided at ALL costs!
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Joe Ricard
post Dec 14 2004, 11:33 AM
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Damn, what decisions I am faced with. Pay off the house of finance a Raby kit. (IMG:style_emoticons/default/headbang.gif) How to talk wife into another motor (IMG:style_emoticons/default/idea.gif)
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Bleyseng
post Dec 14 2004, 12:43 PM
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Why avoid the stock 2.0l rod journal??

Geoff
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Dave_Darling
post Dec 14 2004, 01:45 PM
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Because the Bug rods are cheaper and easier to get. The extra width appears to not be necessary, and the only really high-quality Type IV rods are priced like they were made of gold and platinum. (E.g., Carillos.) You can get some really stout Bug rods for relatively cheap--see some of the earlier posts.

Since you're having the rod journals completely re-worked anyway, why not make them the correct size to work with the less-expensive rods?

--DD
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cnavarro
post Dec 14 2004, 02:45 PM
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Mike,

Go with the 96s if you're going to stroke it. I can always try to return the 94 pistons in exchange for the 96 KBs. Drop me an email so we can be on the same page before I send out anything to be plated :-)

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance
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Jake Raby
post Dec 14 2004, 02:51 PM
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The stock 2.0 journal on anything more than stock creates a situation where you MUST retain a stock 2.0 rod. There are NO rods other than Pauter (suck) and Carrillo($$) that will work on the 2.0 journal! Using the 2.0 journal puts a whole new list of challenges in the assemblers list of hurdles.

The 2.0 rod is 800 grams, too short and has weak bolts. The 2.0 journals also have no possibility of using a tri metal bearing because nothing is produced for them by Clevite thats better than stock.

The 2" Chevy or 2.165" TI journal is the best choice, especially the TI because it makes for a stronger crank due to less overlap from throw to throw than the stock 2.0 or the 2" Chevy

We only use 2" Chevy on cranks larger than 80mm, and only the 2.0 crank journal on 2056 engines and low performance applications, or where the rules say we have to keep them (Damn SCCA)

The TI journal is the BEST journal on the planet for these engines in every meaining of the word- From weight to ratio, to efficiency..
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Bleyseng
post Dec 14 2004, 04:25 PM
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Well hell, I was thinking of using the stock rods with 103's as the bottom end only has 10-12k on it. Would like to make good power to 6000-6500 rpms as the crank is CW.

Geoff
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Eric_Shea
post Dec 14 2004, 04:32 PM
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I'm telling your wife. (IMG:style_emoticons/default/cool_shades.gif)
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Mueller
post Dec 14 2004, 04:39 PM
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QUOTE(Eric_Shea @ Dec 14 2004, 03:32 PM)
I'm telling your wife. (IMG:style_emoticons/default/cool_shades.gif)

hahaha...I should probebly delete this thread in case she figures out how to visit the site....

Charles...e-mail sent (IMG:style_emoticons/default/wacko.gif)
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