Dcoe soft mount vs hard mount

[AceAndrew]

1 hour ago, golf02 said:

 but I am over thinking things 

 

Yes, you are.  At this point, it's time to setup some tests to get some delicious data.... or it's all speculation.

 

Heat shields are going to be more common on setups where the carbs sit on top of the exhaust manifold/headers (a la datsun), functioning as a sink from the head heat ...... well, test time!

[Tommy]

6 minutes ago, AceAndrew said:

Heat shields are going to be more common on setups where the carbs sit on top of the exhaust manifold/headers (a la datsun), functioning as a sink from the head heat ...... well, test time!

I was just going to add this about the shields. Exhaust is hot enough to radiate heat through air. There a shield is effective as it reflects the heat back away, thus prevents it absorbing to the carb. It doesn't function as a sink but, well, as a shield

[golf02]

A reflector of infrared heat and a passive radiator. Luckily the exhaust on our cars is on the proper side, in this case the other side

[golf02]

Ok so aside from the super fun diversion into heat transfer and thermodynamics, has anyone just used a single gasket and deleted the spacer/phonelic/Bakelite insulator. Not that I have an aversion to the super fun synchronization dance, or experimenting.

[AceAndrew]

Yes, while I like the phenolic spacer ..... frankly, I haven't found them to be a critical component (generally speaking) for a fun street car.

 

Edit: However, this isn't hard-data backed, just casual observation.

[uai]

I made my own phenolic spacers with and without o-ring seal and with or without synchro pickup in various thickness.
I can offer some as I have some left in 10mm and 15mm however shipping cost to US is a tad prohibitive.

 

Edited February 7, 2022 by uai

[jp5Touring]

My DCOE 40's run just the paper gaskets. The car came that way and I don't know any better.

Webers have alway ran pretty good with very few problems for a couple of years.  

[dirving]

I put spacers on with paper gaskets and Hylomar spray. Seems to make sense but limits air cleaner choice. Closer to booster. Just did put the carbs on. 45's. Maybe curved horns from IE. it's always something 

[jp5Touring]

My paper gaskets are on dry is this the norm ?

[AceAndrew]

dry paper gaskets are fine.

 

[Preyupy]

I have seen many DCOE carburetors with cracked bodies because someone did not understand the loads put into the mounting ears when they are un-supported when you use the soft mounts.  The worst thing I have seen about solid mounting them on 4 cylinder engines is in the old days of BRASS floats we saw a slight increase in the failure rate of the floats.  In 40 years (probably about 250K miles) of running DCOEs on my car I have replaced 2 brass floats.  Depending on the type of throttle linkage you are using, soft mounts make it very hard to keep them in Sync.  

[halboyles]

58 minutes ago, Preyupy said:

Depending on the type of throttle linkage you are using, soft mounts make it very hard to keep them in Sync.  

Very true!  Which is why our linkage system mounts on the carb ears not on the manifolds just like the original 1600/2002ti.  That way the carbs and linkage move together.

Shameless plug coming up:

 

[Greg Mierz]

On 2/7/2022 at 10:18 AM, Preyupy said:

The worst thing I have seen about solid mounting them on 4 cylinder engines is in the old days of BRASS floats we saw a slight increase in the failure rate of the floats.  In 40 years (probably about 250K miles) of running DCOEs on my car I have replaced 2 brass floats.  Depending on the type of throttle linkage you are using, soft mounts make it very hard to keep them in Sync.  

 

[Greg Mierz]

The worst thing I have seen about solid mounting them on 4 cylinder engines is in the old days of BRASS floats we saw a slight increase in the failure rate of the floats.  In 40 years (probably about 250K miles) of running DCOEs on my car I have replaced 2 brass floats.  Depending on the type of throttle linkage you are using, soft mounts make it very hard to keep them in Sync.  

 

I'm solidly with Byron on this one, I've had my Tisa 45 15/16's on paper gaskets on factory ti manifolds ported to for 45's and with over 40 years and 350K miles I lost one float.  Keep it simple and things work best

Edited February 8, 2022 by Greg Mierz
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