28 replies to this topic

[LXCHEV]

Hi guys,

I have been considering trying a carb spacer on my engine to see what it does.

Firstly, my basic combo is 383 Chev, 10:1 comp, Iron Lightning heads, Edelbrock RPM Air Gap DUAL PLANE intake, 825 Mighty Demon d/p, solid cam, Tri-Y pipes.

Being a Dual-plane manifold, I've read on a lot of american forums that I am probably more suited to a "4 hole" type spacer, so the fuel doesn't get confused and still sees a true dual plane.

However other people have said an "open" spacer could work well too (MRSLR as an example said he used to run an open spacer on a dual-plane intake and saw good results).

Do you think my combo is even suited to running a spacer at all????

What about these "Super Sucker" type spacers. I keep hearing great things about them. There is a "Street Sweeper" available specifically suited to my Air-Gap dual plane.

Lastly, what about plastic type spacers? Gotta be great for reducing heat transfer/saturation of the fuel bowls etc. Are these ok for street cars that lots of km's? Should I use 2 spacers? One plastic and one aluminium?

Thoughts? Ideas? Comments? Past Experiences? Recommendations???

After spending hours on the american forums, I've found this to be a very interesting topic!

[makka]

basically Brett, the open spacer will give you more top end and the closed spacer will give you more bottom end/midrange. I want to grab a few spacers before the drag day/test n tune to see what difference they make.
I ahve just gotta find a closed spacer for a quaddy, not easy!

[Tiny]

Definitely worth a go mate.

I'd go with a plastic spacer ( well.. not aluminium.. ) the heat transfer saving is enormous! Ive also seen a marine-ply spacer used.. on none other than BWARND! (Before the turbos of course!).

I think the only way to know what's going to work is to give it a go. Try to borrow a few different types and then put em on and drive em! Seat of the pants dyno i reckon!

Be ware that the spacers could be warped causing air leaks.. ive heard of guys using two gaskets to stop this.

What are you trying to gain from using the spacer? More top end? Fatten up the bottom end? That will steer you toward what spacer to use too i think!
Best of luck mate
Cheers!

[dattoman]

I have a 13mm phenolic 4 hole to go on my 383
Very similar sounding combo to yours but with alloy heads and smaller BG carb
On and no roller cam either

I bought it to stop heat soak more than gain HP
With the extra cubes you can afford to probably lose alittle down low and pic it up in the higher rev range if your comfortable seeing higher RPM numbers and want more top end.
Personally I don't want the big high end HP myself and want to keep low down grunt for street use
No drag racing for me........ oh...... maybe once or twice so I can run an 11 before Tiny (dreamin)

[LXCHEV]

Yeah my car is still aimed at street driving too, with the aim to hit the strip a couple of times a year (call me a part-time drag racer!).

My reasons for wanting to try something Tiny is pure curiosity. I've heard various stories of people having great success (like 1QUICK LJ mentioned, huge gains throughout the rev range). Who knows what potential could be hidden just waiting to be found.

I am planning to book some dyno time in the near future, and perform a series of back to back pulls, so that's why I'm trying to go in with a battle plan of what to try.

I've heard several people now say 2 spacers have proven good (one open and one 4 hole used together).

Generally speaking, most success stories I've heard have been from people using single plane intakes, so there's a very high chance my combo may not even be suited to a spacer of any kind.

It's also quite common for people to "tune their setup" with spacers for strip work, by changing where the torque peak occurs, thus reducing/removing problems with traction (which is not a concern with my car at present anyway).

So yeah, lots of unknowns, that's why I'm just trying to get as many stories of people's own personal experiences as possible....

[Tiny]

Dattoman: is that a challenge!? *GRIN*

Brett: Fair call mate! I'd settle to get my car GOING again before i even think about fine tuning like this! hehehe.. Sound like your on the right track though mate! Best of luck!

[LXCHEV]

Cheers.

I would love to see that drag race:

dattoman vs Tiny !!!!!

[LXCHEV]

I have a 13mm phenolic 4 hole to go on my 383

I bought it to stop heat soak more than gain HP

dattoman what are your thoughts on these phenolic units? Some people (and even some companies who sell them) say they are not suited for street cars that see lots of km's, but only for drag cars they run in short bursts.... As they are a plastic type product, they can actually melt.

As weird as it sounds, perhaps I should make a nice redgum wood spacer! (It's not uncommon for people to use wood)...

The 1" phenolic 4 hole does sound tempting, and it's very affordable, I'm just worried about the whole melting issue! That would not be cool!!!!!!!

[Stedz_lc]

Mine hasn't melted yet! Ive got one of those plastic "like" ones on my 308 four hole thing n it hasnt' melted "yet". Ive heard the redgum wooded spacers are the
GO! A mate was meant to do me one for my six.. Still waitin!
Cheers
Stedz

[LXCHEV]

Awesome. Do you know of anywhere that actually make them and sell them (Redgum), or is it a matter of making them yourself??

I still might play with a phenolic though...

[Tiny]

I think phenolic spacers are made from bakelite which is virtually indestrctible plastic. i dont think that heat or fuel would worry them!

There is also a spacer/anti vibration made by a perth company.. i saw it in perth streetcar magazine but it cost likr $300 odd bux!
They claim some pretty interesting stuff though.. may be worth a look!

Cheers

[LXCHEV]

I think I've seen the same add in one of our local car mags too Tiny. Certainly looks impressive. It says the carby is completely isolated from the manifold (ie. no common bolt that goes the whole way).

Is vibration really an issue here though???

[Tiny]

Yeah thats the one i'm talking about!

Ummm I dunno really though, I was thinking the same as you about vibration! I think maybe on dirt track or race cars it may be more of a worry, but i dont think we would need to be too concerned about this even on the 1/4 mile!

Just a thought

[Struggler]

My personal experience... I was using an RPM Air Gap on my 355SBC. A 1" open spacer really woke it up. I then fitted the same manifold to a mates 383 and the spacer made absolutely no difference. I guess you will just have to try it on the dyno.

A local dyno operator has had a lot of success with those isolated spacers made by the W/Australians.

[dattoman]

Yes Tiny thats a challenge
When the cars finished

I bought my phenolic spacer off ebay from a CNC machining company. Nice and cheap and exactly what I was after
Yes they are made of a non melting substance

You'll have to experiment to get whats best for your engine. Not just in dyno HP but driveability too

[Tiny]

Thats them Wombat... Havent tried a stub stack sorry!

[LXCHEV]

A local dyno operator has had a lot of success with those isolated spacers made by the W/Australians.

Struggler - can you tell us any more specific details with regard to this comment??? I am getting very interested in these spacers now....

[Struggler]

A local dyno operator has had a lot of success with those isolated spacers made by the W/Australians.

Struggler - can you tell us any more specific details with regard to this comment??? I am getting very interested in these spacers now....

No specifics sorry, but I noted he had a few of them and when I enquired he mentioned they where worth the $$$ on everything he had tried them on so far. The guy is very switched on and I have no reason to doubt him, if you like I will get a hold of him and get some more details.

As for the Stub Stacks.... I have found they work well if the carby is a little too big for the application. On correctly sized carbs I have seen cars gain 2 tenths by removing them. I had several and tested them fairly comprehensively, I then sold them off.

SuperSuckers.... I have also seen them go both ways, try one before you buy it.

Proform carb bodies....... I have always had a win with.

There is another product I am looking at in the States that may be beneficial to those running an aircleaner on a 4 BBL carb. I am in the process of getting one and will also test it both on the track and on the dyno.

[Struggler]

Here is a link to the W/Aust Spacer...... http://www.kec.com.au/

Edited by Struggler, 21 July 2006 - 06:41 PM.