Looking at making up some of these. These are intended to help insulate the carbs from the engine further at the carb base. Who's interested?

These were available at one time for $15 each. I should be able to do a set of 4 for $24, if i can get some quantity.

Figured I'd see how much interest is out there.

I've always used insulating gaskets on my -6s, so I imagine they'd also help on the carbed -4s.

2:32am? When do you sleep? Looks like they will fit on any intake that accommodates IDF or DRLA carbs.

When I had carbs, I just used the standard FI phenolic spacer to get insulation from the heat of the heads.

Zach

Zack, the spacer would go in between the carb and the intake manifold. Further insurance against heat soak.

I made my own for my six project. Hated machining the stuff, wear a mask.

I've been having issues with heat transfer... I'd be in for a set!

That's a good idea Mark. Priced very reasonably as well. Could we also request gasket sets that go with these? Currently I order mine from CB Performance but it's an arm and a leg to ship from them for whatever reason.

To install the phenolic spacers, one would need 8 individual gaskets for a dual carb setup.

Interested in a set!

Chester

I'm not familiar with this concept...

> I've been having issues with heat transfer... I'd be in for a set!

How do you know if you are having issues?

-Steve

if its hot outside or when the engine sits when hot you can experience heat soak to the fuel in the float chambers. can make for difficult starting until the cooler fuel is on board.

They are stock on type 4 FI, a set comes in the gasket set, manifold to head. Heat soak leads to percolation, vapor lock, bad running issues.

Are these for the carb to manifold?



I would add the extra gaskets as well so peeps don't have to source them separately.

I would be in for a set of 4.

Thanks Mark!

yes mark, in-between the carbs and the intake manifolds.

I'm in for a set.
Barefoot

Yes I could do them up easily, maybe $2 a pop depending on the material cost.

In for a set

I'm in for a set!

I'm in for a set

I'll need some for my /6 conversion...not sure where's the best place to get 'em though.

Hey Mark!

I'm in for a set of four!

I'd be in for a set as well.

I think the IDA pattern is different than the IDF so these may not work on /6 carbs.

I made mine but they go on the bottom of the manifold, to go this route if you have FI pockets you have to use PMO manifolds. You can get phenolic spacers from PMO, they may come with manifolds.
Stock manifolds don't have enough meat on the base and they will leak over time. I got around this by making aluminum spacers as well. This also helped raise the bottom of the manifold making it fit the shroud better.

I can only find this pic and it's the wrong way. The aluminum spacer should be on the bottom.


BTW it would be hard for Mark to offer these as he would have to stock a whole bunch of different sizes.

PMO makes these for the /6.

Oooops.... I see Mark just said that. I've made the same aluminum spacers for the FI port too.

I had planned on doing the IDF, but as long as the IDA is covered no need to go there.
Mark

FYI, the Dellortos use the same bolt pattern and bases as Webers IDFs, so if anyone has Dells, these work for you too. Support Mark, an awesome vendor!

Just curious.
I have used just the head-->>manifold phenolic spacer and I have never had any heat issues on the manifolds or carbs.
Sure, there is some heat from the studs, but never enough to make a big difference.

Also, with these added gaskets, you are moving the throttle plate further away from the valve which does have a negative result.

So, why add these?

Rich

Great info guys, thanks. If I still had my carb'd /4 I'd grab a set in a heartbeat.

Any time you can get heat away from the carb is a good thing. Could be worth 1-2hp by cooling the intake air more than just the head spacer.

When using these spacers are gaskets used above and below the spacer?

Yes, one above and one below. Multiply by 4 barrels = 8 individual gaskets.

I'm in for a set of 4. Thanks

Mark, I'm in for two sets. I second the request for gaskets as well. Thanks as always.

In for set of 4 and 8 gaskets

Rich
What is the negative result and how is it any different than adding tall manifolds that are better for top end? Do you really think a few mm spacing will make a difference?
Bruce

I believe the benefit is the phenolic spacers stop the heat from traveling up the manifold.

Mark,

I'm up for a set of 4 w/ gaskets.

If the timing works to save on shipping, you can add to the upholstery order.

Thnx!

Yes its an insulator. In the summer down here in Texas fuel percolation is very common on my AX car. Any little bit helps.

You want the throttle plate as close to the valve as you can get it.
Tall manifolds do not do that.
Adding a spacer moves it away.

I do not have data at my fingertips, but it's fairly common knowledge when tuning a car on a dyno.
I believe Chris makes, or did make short manifolds from the commonly available tall ones.

There is also a difference with tall velocity stacks.

In my experience, the farther the throttle plate is away from the valve, the higher up in the RPM range your power band will be.
For autocross, torque is king, so short everything, manifolds and ventures.
I swapped tall and short manifolds on the same car.
Short ones have a quicker throttle response, lower power band, more torque sooner...all for autocross.

as Jake says, it's all in the combo, so if you like high end revving, you can build your transmission to match your intake flow dynamics and tall parts might work for you in yr specific application, and temperature.

Rich

I've used similar spacers with Weber IDFs when I had my 356 SC. Never seemed to make a difference. The carbs always boiled off when fully up to temp after sitting for a while. That was here in the Florida summers, maybe that was the difference.

Ansbacher

http://www.jenvey.co.uk/jenvey/throttle-bo...jenvey-dynamics

Read the part on system length. It's not always a bad thing.

I had a reply, but I don't really want to argue. Lets just say I don't agree with Rich.