Engine Size

I'm getting ready to rebuild or build a new engine for my CMC. I am receiving two different opinions from two different mechanics in our local shop. One wants me to go with a 1915cc dual 40mm Webers, etc. the other a 1776mm with a stroker crank which will end up as a 1900cc plus. What's everyone's opinion? Oh, at present I have an 1835cc with the 40mm dual Webers, stock cam. Why the person would have ever build an 1835cc dual Webers with a STOCK cam is beyond me. It's the way I bough it.

Paul

Oh...The strokder mech says I can use the stock rods with a stroker crank, in a 1776cc. How can that be?
Paul

Sorry Paul, but a 1776 is not a stroker.....:) (tell that to your mechanic) These are my preferences; just take them as another opinion but my goal is toward decent power and longevity equal or better than stock. In essence, go with the 90.5 cylinders because the wall thickness is the same as stock thus giving you good heat dissipation (I've also heard that the 94 cylinders have the same wall thickness too but I would prefer not to take that much material away from the case and heads.). Also go with a full flow system and if desired with an extra 1-1/2 quart oil sump. Definitely use a good quality forged counterweighted crank (up to 82 mm will let you use the OEM VW rods) and use a mild cam or the stock cam with 1.25 ratio rockers. Get all internal engine parts balanced; including pistons, rods, crank, pulley & flywheel. Get the heads cc'd. ported and polished and use a good non-restrictive exhaust. Your existing carbs are great.With regards to the cooling system, keep all factory cooling tin, flaps, thermometer and shroud. If desired get a welded and balanced fan and use a 356 generator pulley.

Find a different (and competent) shop.

Ricardo, I think what he was saying was, he could use the stock rods with a stroker crank, so he wouldn't have to buy new rods, and I think that is correct as long as you don't go more than one step up on the crank.

An 1835 is a 1776 with 92s, and a 1915 is a 1776 with 94s. A stroked 1776 can be a 1903 with a 74 crank, or a 1955 with a 76 crank. In general a longer stroke will give you more torque which is what you want for the street.

Paul, if you go to a 1915 from an 1835, don't expect to notice an improvement in power, unless you go with a good cam like a webcam 86b, and get some work done to the heads, and use a good exhaust as Ricardo has said.
Ron

I would buy a longblock from someone reputable...it is a little extra money, but from my experience the local shop rebuild takes too long and they don't stand behind the engine, even if they screw up.

I had my engine out twice in 6 weeks in my IM and it was because I thought it would save money to rebuild the longblock. It would have if they hadn't of screwed up one cylinder and caused me to pay them to take the engine out again.

,,,,,Ricardo, I think what he was saying was, he could use the stock rods with a stroker crank, so he wouldn't have to buy new rods, and I think that is correct as long as you don't go more than one step up on the crank

An 1835 is a 1776 with 92s, and a 1915 is a 1776 with 94s. A stroked 1776 can be a 1903 with a 74 crank, ........
.........
Yes, that's what I, the mech, was saying. Go with the 1776cc then use a stroker crank to make it 1900cc. As far as exhaust goes, I am kinda stuck because as I usderstand, a lot of really nice exhaust systems wont fit under the CMC body. I think mine was built in the early 1980's
Paul

I understood what the mech was saying, basically use the same block with the 90.5's (a good choice from my perspective) and swap the crank for a stroker of your choice (don't go over 82 mm if you want to use stock VW rods). I also forgot to say that if you lower your compression ratio to around 6.9 to 1 engine temp will go down with today's lower octane gas and that will also translate into longer engine life.

With respect to exhaust systems for CMC bodies, my friend JJr is experimenting and shopping around. We know for a fact that the Monza or EMPI 4 tip clears the rear apron but it looks too VW for a Speedster replica. Since his Monza system broke he stuck in an old used Tri-Mil header and tuck under muffler that he had laying around for years that is a little bit low but works. He's got that in until he finds a better solution (Tri-Mils and large dual tip VW or EMPI units as used on VS and JPS won't clear the rear apron on CMC's).

Paul, I went from a 1776 (low CR), with 40 Webers, to a 2110 (low CR) and 44 Webers and I could hardly notice the improvement. I changed two things and noticed a BIG improvement in power; first, I put in a Web 86b cam, and second I bumped the CR up to around 9.2 to 1. I kept the valve size on the heads small, but had a very good port job done. The end result was a fast car with lots of torque....along with a PITA cylinder/head leak....which is another story. A CD box and Mallory distributor allowed me to pass our 'air care' testing withou having to adjust the valves and change jets, and the car seemed to run 'crisper' with the CD/Mallory.

Thanks for all the help, from all. Let me/us know what your friend comes up with, as far as a CMC exhaust. My heater is next to worthless, so, I can go without the heater boxes. Plus, I live is southern Arizona.
Paul

Hi Paul
Have you found an exhaust system for your cmc? Im still trying to figure out the best solution for mine. There are a couple of systems out there but need something that will fit and non restrictive. Any ideas you could please share? - jJ

I'll let you know what I come up with. Right now I have a problem getting it to Tucson to be fixed. I borrowed a friends Ghia Towbar and it will not fit. Where his bar attaches is where the CMC body is attached to the front sus.

Paul, JJr can jump in; I recall he told me that he towed his CMC, while it was being built with just a regular tow bar for VW's. It didn't have the front bumper though.

I would be tempted to just drive the car; about 40 miles. It still runs on three cylinders, but #3 plug is missings and I worry about the chance of a fire with all that gas not being burned. Why would a Ghia tow bar be any different than a VW one?
Paul

I don't know if the towbars differ; all I know is that JJr's CMC didn't have the bumpers on when he towed it and it worked like a charm. If I were you I wouldn't drive the car like that; 40 miles is enough distance to damage the engine.

Ghia and VW type 1 Beetle tow bars are the same, excluding the Super Beetle ...it uses a different tow bar "but we know" that speedsters don't utlize these as a donor)
All of the Beetle tow bars are fabricated to fit just inside of the vert. axle beam supports.
It may come in contact with either the grease fittings and or the the front sway bar / may have to be removed .

Thanks for the clarification Alan; if I recall correctly JJr told me that at the time the car had the stock VW sway bar and he towed it successfully.

Hi Paul;
There are a couple of choices for the exhaust to look at, there is a nice online catalog with pix in mid america motorworks site, check it out.
I own the type 1 towbar, it costs around $50 and works like a charm for the cmc 356. The detail with it is that it won't work with the bumber mounts attached to the front beams. You would have to remove them in order to use it. I was thinking about modifying it to attach it to the bumper mounts, all I need is for short trips to get me out of trouble like in your case. But if you can deal with removing the bumper brackets it will work fine. About sway bars, I will have to see if it will work with the beefed up sway bars installed... sway bars may be an issue good point Alan! Good luck - jJ

I need to clarify , the stock sway bar is not an issue it is the larger 19mm aftermarket ones that sometimes are mounted upside down

My problem is, the front bumper mounts attach RIGHT where the standard type 1 VW towbar attaches. It looks as if I'll have to take the towbar and do some cutting and welding, make the attaching clamps closer together. My son, a NASCAR mechanic actually suggested taking the #3 intake pushrod out.... and driving it to Tucson, 40 miles, on three cylinders. With the pushrod out, his thinking is, no raw gas would be going into that cylinder, thus the fire danger would not be as big of a problem. Than't too much trouble; yet, it might work.
Paul

Paul I don't think driving the car on 3 cylinders for 40 miles is a good idea....

Thats the same problem I have Paul, they attach right where the towbar hooks on, but Id rather take out 4 or 6 bolts and the bumper than risking the trip with engine trouble... but thats just me. I dont know if you have the sway bar installed. Hope everything goes well with you.
Alan, I have the beefed up sway bar but mounted correctly, it is larger than the stock unit, so you might still be right about the towbar not hooking up, will have to experiment and see.

I'm having the car towed to Tucson on Tuesday, $125.00 I think we could modify the standard towbar and make it work on the CMC.
Paul

Ricardo wrote:
"I don't think driving the car on 3 cylinders for 40 miles is a good idea...."

So......what's it gonna hurt?

He pulls the intake pushrod, so no gas is getting in to wash the cylinder walls.

The cylinder gets lubed from below, for the most part, so no big deal there.

There'll be no power in that cylinder (DUH!) so it'll be kinda dead, but if I were doing it, I would probably pull that spark plug, too, and just head out.

40 miles? No big deal....besides, not a lot of hills near Tucson...

But, since he's towing it anyway, this is all moot.....

I drove a dune buggy once, from Provincetown on Cape Cod back to Worcester, MA., on three cylinders (I blew a plug right out of the head) - distance is about 125 miles. Ran like a slug (it was only 36 hp in the first place) but it got me home. Plugged the carb throat, shot some compressed air into the intake manifold (to keep metal chips out of the cylinder), heli-coiled the plug hole for new threads, installed a new plug and ran it for another two years til I sold it (the new owner ran it for another three years).

40 miles? no big deal...

Gordon youre my hero! Do you think you can send me the template for that behind the engine compartment plate? Let me know what you require and thanks in advance...

JJr:

Check your email......

gn