looking for ideas. Mine is cut but it not large enough to be useful. So I'm going to enlarge it and would like to see others solutions.

I know it's kinda tight in there, but i really don't think it's needed at all.

I replaced the alternator, engine harness and belt on my 3.6L and it wasn't that hard to do.

I think that perhaps just getting a larger cut piece of the firewall from another parts car would allow you to overlap a cutout and fasten it with Dzus fasteners. The thickness of the overlapping areas should be inconsequential.

I made a cardboard template to cover the opening I made. About 3/4" bigger all around than the opening in firewall. I traced it onto a sheet of aluminum and cut out with my jig saw. I used a rubber mallet to shape it on the fire wall. I tack welded 8 small nuts on the engine compartment side to make for easy removal/install.

From the F-914 build in my signature.

i have a large piece of firewall. pm me if interested. include your email so i can send pics. mark

I installed a zipper and sprayed it with rust.

The last race car had a similar opening like Krieger's. Sheet of aluminum covering it with screws holding it in. Never needed to use it though.

After cutting the opening, I spot welded an 1/8" thick reinforcing ring and then drilled/tapped for the cover screws
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Scotty and I were just discussing this for my Six. I really do not want to cut a hole in the firewall but I do acknowledge that access would make life easier if I need to replace a belt or alternator. What is the general consensus here? I am leaning towards no hole, but could be swayed..... Although Andy's post gives me hope this can be avoided.

No hole.

Not easy to see, but we just did a very clean/straight cut out, made an aluminum 'door' just a bit bigger, and used hinges on the bottom and 1 dzeus fastener on top. Very simple. this way there are no screws or nuts to deal with that might get dropped or lost when you open it up. Painted it when I painted the interior.

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Not in an orig 6. Bend a wrench to fit around the fan and keep in in the car. There was a thread on this about a month ago. Actually, have scatty make 2 since I want one.

I vote for easy access in the dark on a lonely road in the mountains, or on the track between runs. What's likely to happen? Perhaps a broken or compromised fan belt. Mine gets inspected and replaced fairly often so it's never happened to me, but it did when I had the PO installed 2.7L. Not an enjoyable operation. My thinking on the size?

I choose not to give myself cramps trying to do two-handed operations through a small hole.

This access hole lets me do anything I need to do, including getting the spanner onto those 3.6L pulley holes and fussing with the shims on the fan pulley. The metal is thin enough to snake out from behind the cage-crossmember, thick enough to still be a firewall, and with the Dzus fittings, is easy to remove/install. The only thing I have to do is remove the passenger seat, a 5-minute thing. When on the road, I carry a huge plastic bag to cover it if it's raining.

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For those that don't put a hatch in how do you time the engine?
Is FI a pre set and forget?
And Andy how did you get the alt out? Do you have a 2 piece shroud?

My engine is a twin plug/MSD with webers I have no idea how to time it easy without a hatch

My one and only experience with replacing a fan belt on a /6 with the engine in the car was at night, on a Texas freeway, 1000 miles from home. I had only owned the car less than a year. Luckily, it had the full toolkit and a spare belt. After waiting a while for the engine to cool down, I was able to replace the belt with just the factory supplied tools. Not easy, but doable. I would think it would more hassle removing the seats and back pad to get to an access panel than just doing it the 'right' way. And how often do you need to change a belt anyway?

Regarding the timing, on a factory six, the timing marks are on the flywheel and there is an access hole in the case. Very easy to put a timing light to; just a little unnerving adjusting the distributor to full advance at 6000 rpm.

On my 2.7, also MSD, I timed on the flywheel with a degree-dial type light. Ahead of Andy's answer, the DME is 100% computer controlled and the distributors are fixed. The 3.6 has a two-piece shroud which makes the alternator job easier.

Interestingly, I discovered when Andy told me there was a factory recall on 993 engine wiring-harnesses, my large access hole allowed me to tilt the fan forward without disturbing the fanbelt pulley. Saved a fair amount of time, but effects only 993 and perhaps 964-engine 914's.

I have the hatch and I have the hole in the tin for timing. It's hell to be standing, shooting the light at the hole and marks on the flywheel and then trying to turn the dizzy.

Also, when fitting the early flywheel to a 2.7L at least, the marks on the flywheel are way off.

I use the hatch ... pull the seats and backpad ... easy peasy ... remembering Moab 2014 ....

I will be adding the Electromotive HPV-1 system next ... worst part is getting the sensor lined up with the 11th tooth ... after that timing is not a problem.

and would have the same opinion if my firewall wasn't exposed.

I use mine all of the time...
in fact I used it again last weekend, and practically open it every single post-race

but its a race car
I wouldn't do it on a street car

I just pulled my seats and pad, I didn't think it was a big deal. I wouldn't pull them for just a belt.
Still thinking on this, high compression twinplug, I don't want to be fuching around with the timing too much the wrong way.

Yes, two piece shroud:

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Don't need a hole to replace the belt. Here's my trick!

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Wouldn't work for me, I'll have to get a different pulley and I don't know what the hex key is for...

If you have a large access hole in a fire wall, shouldn't it be steel rather than aluminum? Wouldn't steel be safer? Maybe I just worry too much.

I am going to say this again:

What part of the word FIREWALL do you not understand?????

Cutting a hole in a firewall is a good way to get badly burned if you have an engine fire. Betty and I were in her car when the engine caught fire. The firewall gave us time to get the car pulled over and to get out of the car. It was very bad. If we had a hole in the firewall, the flames would have been in the car with us at 65 mph. That would have been even worse.

No matter how convenient, don't cut a hole in something called a FIREWALL!!!

Steel only for me. Clay brings up a good point though.

There ain't no fire gettin' into mine. Dual seals against that and the cover has a very large overlap.

No firewall access hole in my Six. Decided.

Hex holds the alternator shaft. Instead of the special $30 alternator pulley wrench.

Here's the first class job that Josh did on Kermee.....

Wndsrfr, I'm afraid the plexiglass/lucite cover isn't really fireproof enough to keep you safe... might want to rethink that material.

Per firewall...if Porsche put a hole for the Boxster I'm sure the 914 can be done safely if one really wants a hole. With the proper material of course.