1904 vs. 2005cc

[rickb67]

I am thinking of building either a 1904 or a 2005cc engine. I am not at al concerned with gas mileage!

My car is mostly just driven on the street but I would like a little more power than what I currently have. I am running a 3.88 transaxle with welded gears, super diff, and a taller 4th gear. Currently I am running a 1776 with dual 40mm HPMX carbs. I am planning on using my current heads and pistons for now.

My case was line bored for the 1776 build and I have read some very negative things about line boring cases. So I figured I would go with one of the two strokers that I have listed.

So I have a few questions about the different choices.

Would I absolutely have to change carbs from 40mm to 44mm?

Could I just simply re-jet the 40mm?

Would I need an external oil cooler for either engine?

Any reliability issues with either engine?

I am planning on using CBs super race rods, 2234 cam.

I would like to switch over to A-1 sidewinder exhaust with dual outlets. (that is if I can ever find one in stock)

Any suggestions would be much appreciated!

[jtwaller]

I am running the 1904 and am real happy.
1904cc
CB's "El Panchito" heads
Engle W110 cam
Weber dual 40"s
counterweighted crank
AC.net SVDA distributor
shaved the top of the piston heads to run stock push rods
no oil cooler
daily driven up until a month ago
went on 6 hour drives to car shows with no problems.
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1967 Daily Driver
..[-_-_-_-]..
*/l_____l\*
( O \ ! / O )
1973 Thing
1969 Squareback
1967 Bug
1968 Bug
1971 Bug

[jfats808]

For the most part, always build as big as your budget allows. Larger Stroker are most always > 69 strokes. With the budget priced panchitos, you have a multi small stroke head choice selection.
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2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

[midtravelmidengine]

You can keep your 40s with either of those engines!
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[modok]

I agree. the HPMX can handle 32, even 34mm vents.
If stock heads go 74 stroke, if big valve heads go 78 stroke at least.

[mark tucker]

for the most part the carbs dont care what size the motor is, they are not jetted for cc like some think. the jet corasponds closely to the vent size.then cr exhaust& a few other factors come into play. about the only time is when you have carbs that are too big and cant pull enough fast enough so you can cheep with carb work. but better to size the carbs down.. if your gonna stroke it you need new pistons made for the extra stroke unless you have a buggy where the width of the engne dosent matter. so just get a 82 stroke 4340 crank and a good set of new chromoly rods "B"(stroker pistons) of the bore size you want and go from there. it's always nice to let your foot do the power out put than not being there when you need it. and big motros usualy get better mpg too. good luck,do it right do it one time and be done so you can have fun.

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If you are reusing your pistons, a 78 stroke crank is going to create a lot of positive deck height. What heads do you have now?

[mark tucker]

I used a pistons with my 78.8 crank&std rods(5.4 c unitech). .060 head gasket,.090 cylinder shim(I think, might of been from .060~.090. brain fade) and the step in the chamber was opened up .020 more than bore for piston clearance when it came above the headgadget about .030" into the head's step aera. for a .030" piston to head clearance. worked great. but a lot of piston &head work involved. these days stroker pistons are cheep so thats the way to go.

[vugbug68]

A 1904 will be easier to do since you want to use the pistons you already have. What heads do you have?
40 carbs will be fine on either.
You dont need the CB race rods unless you get the 78 crank in chevy rod journal then you wont have to clearance as much.

If you go 78 you might as well get some stroker pistons and might as well get the thick wall 92's and then get some nice heads, cam, exhaust ..... damn it what was the budget again?
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71 Super - Backroad Thrasher
66 Corvair - Weekend Cruiser
90 4 Runner - Muddin

[Rome]

If you decide to go for the bigger 78mm strike, you can save a few $ by reusing your current cylinders. Cylinder length is the same for a stock-stroke as for stroker piston sets. You'll need the "stroker" style pistons (90.5 "B") which have the piston pins located higher up to the piston top/crown, sold separately from the cylinders- http://vwparts.aircooled.net/90-5-x-76-84mm-Piston-Wrist-Pin-and-Pin-Clips-p/vw9050t1sp.htm

[rickb67]

So I would need stroker pistons and shorter connecting rods?

[rickb67]

It has EMPI 042 heads on it right now.

[vugbug68]

[[email protected]]

If you decide on the 74, you could reused your pistons. If you decide on the 78, I personally would get the stroker style pistons. You don't have to get any different/shorter rods.

An 042 is usually referred to when talking about a Mofoco head. Empi has a head called a GTV-2. What I was getting at was if they had bigger valves, or stock valves. If they have bigger valves, some port work will make a big difference in performance.

[rickb67]

The heads that I currently have are 40x35.5 with stainless steel valves and heavy duty springs.

[stan_tichomirov]

Like these?

https://proflowperformance.com/shop/heads/empi-high-performance-cylinder-heads/

Stan
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Aircooled.net
Jansen Enterprise
My 1835cc build
My budget 2276 build

[[email protected]]

The biggest bang for your buck to me would be to have your heads/combustion chambers ported, and your case clearanced for the 74 stroke with stock VW rods. That way you could use the pistons/cylinders/rods you already have. You could use the money on the heads, instead of buying aftermarket rods, and another set of pistons/cylinders to build the 78mm engine without porting your heads. Sure you could get a 74mm Chevy journal crank made with a set of 5.4 H Beam rods to limit clearencing, but the only difference in performance would be the minimal lesser weight of the crank/rods. Jim's Custom VW's in Columbiana Ohio isnt too far from you. Jim does excellent head porting, case work, and could get you what ever else you would need for the build. You could also get a little bigger cam to add some more drive ability if you got the port work done.