DCOE 40s

[jdoclogan]

Makes it a lot easier having a right hand drive for installation. I agree it is a joy to drive and the sound turns heads everywhere. I also agree with the distributor modification, you can't use a vacuum advance system with dual DCOEs. Jeff from Advance Distributors http://www.advanceddistributors.com/ was great to work with. However, I decided not to incorporate electronic ignition after the first Petronix system failed and Jeff said it wasn't the best way to go.

 

[alpine_64]

Makes it a lot easier having a right hand drive for installation. I agree it is a joy to drive and the sound turns heads everywhere. I also agree with the distributor modification, you can't use a vacuum advance system with dual DCOEs. Jeff from Advance Distributors http://www.advanceddistributors.com/ was great to work with. However, I decided not to incorporate electronic ignition after the first Petronix system failed and Jeff said it wasn't the best way to go.

As my car was not as original as yours I went to a Bosch Scorcher ignition that was turned down to fit the original drive and tach drive. It is a proper elec setup with magnetic pick-up and is great.. but i did have to switch to a remote resivoir for the brake MC as the dizzy cap was to large and clashed with the stock brake MC.

 

[puff4]

Michael, this doesn't look like the Vizard mod. May I ask, what sort of chamber mod is this, and where did you get the pattern? Is it effective?

 

[alpine_64]

Michael, this doesn't look like the Vizard mod. May I ask, what sort of chamber mod is this, and where did you get the pattern? Is it effective?

Kevin,

No it is not the vizard (rootes chamber) mod. This was done back in 1999 when i rebuilt the motor the first time (before i had heard of vizard)

The head on my car was skimmed quite a bit and we decked the block, combined with the new flat tops i was goign to have way to high comp for a driver.. so the head guys opened the chambers up in a similar manner to some of the other performance work they did on historic group N racers.

I have no flow bench data but can say that the motor was much smoother and more responsive after the mods (but then again there was a full rebuild involved.. so you would hope for improvemets... but the head was good.. i broke some compresison rings due to a variety of factors.. me included)

When i first posted the head mods maybe in 2003 when i went to the webers Jan was concerned the motor wouldnt have enough squish.. but he went off and did some analysis and came back with a nice photoshoped diagram of the squish area that showed t to be ok.. i think the photos i have in the second group are of the head after the 1999-2003 run when i welded up the water passages and went to a custom HG.. kept the same chamber shape.

The head seems to work well.. vs Vizard,,, not sure.. another interesting head mod is Jarrids head.. the hybrid Vizard/holbay/stock one.. he went for increased flow but without the larger compression loss.. and i think he flow benched his.. maybe he can posts some pics.

I will be building another rootes motor sooner or later.. i will probably go for the vizard head mod on a stock deck head and will be using 60 over domed pictons to give me the compression (with a custom HG and welded passages ofcourse..

If you want more details kevin.. drop me a mail and i will give you the info and pics i have.

 

[RootesRooter]

However, if I have got what he says correct, he's the only one who says that well set up CD 150's are as good as the Webers (sometimes better??).

Wally Swift told me that at SUNI II. But as far as I know, he always ran Webers.

 

[RootesRacer]

Unless you are talking about a stock or very near stock 1725, going with CD150s involves a huge compromise in tuning acceptance (burying your head in the sand) or finding another needle application that happens to cure your tuning issue.

Making your own needles is not terribly rational since it would need hard chromed when its qualified.

In the end it just makes more sense going with webers.


BTW, its been quite while since I remembered this, but in my very early 1725 days I had a stock engine (rebuilt) and strombergs. It ran well, had good throttle performance and made decent power (compared the the 1592 it replaced).
Not long thereafter I took the stroms off and installed my first setup (the solex PHH40s) and was amazed how much it woke up the engine.
The sound was amazing and if we considered the 1725 with stroms as 92hp, the weber clones would have been about 105 by the difference in acceleration. This was on an absolutely stock 1725 engine (9.1/1 CR).
I even used the stock ignition which would have been under advanced for lack of vacuum ports on the carbs.
The engine may have lost a we bit at the bottom end but what it picked up at the top end more than made up for that. The new revs it liberated and the extended power curve introduced me to valve float and pitted lifters.

 

[Jay Laifman]

Ok, it's been a while. I've posted this here before. But, I'll do it again.

I drove my Alpine all through high school and college with stock carbs. It was a fun machine. But, then the car sat for many years and I was driving my Porsche 911. When I got back to it, it wasn't as fast as I remembered. Because of all the time in the 911, I just assumed the car was slow to begin with and went down a path of Holbay head, Holbay cam, dual DCOEs etc. - building the Alpine I always wanted.

Let me say that I love it. It goes like stink, no flat spots, sounds great, and is smooth (for the record, despite what others found, I liked how it runs with F11s better).

Ok, but here is the irony of it all. In the process of changing the weights and springs of the distributor to go from vacuum to mechanical, we found that the weights had rusted to the plate from all that sitting!!!! So the reason it was down on power was because it wasn't because of the 911, but because it had no advance!!!

Would I do it again? Probably. But, I will tell you, adding the OD tranny added equal if not greater practical joy to the car.

Two more things. First, I had to put on a shorter, smaller ID master cylinder that I got from Pegasus to fit with the Webers. Second, I took off the cross bar itself. I did a bunch of research in the day and found that the factory added the cross bar because of vibrations it was trying to eliminate - but later found they were caused by something else. I have long since lost the references to it all. Nevertheless, I'm fine without it. If I was racing, I'm sure I'd be required to have it. But, I'm not.

As to the Tiger power thing, as I understand it, my Alpine has more hp/lb than a stock 260 Tiger. Different rpm power band. But, don't think that the Alpine is always a loser to the Tiger.

Jay

 

[RootesRich]

Yep, and I knew it from the very beginning and just forgot about it during all of the fiddling. In fact, it wasn't until I took them off that I realized that I was doomed from the beginning. While I have a stock Rootes manifold that could be cut and welded, I think my best bet is to fix the Redline one by having a good machinist weld up and re-drill the holes on one side. What I really need to do is send them to Jose's old partner, Jim Moyers. That guy is an artist and I am sure he could do them right.

Jim, is the offset noticeable without installing the DCOEs or something I could check with a straightedge? I'm curious if my manifold is flawed as well or yours is an anomaly.

 

[RootesRacer]

A straight edge across (on a tangent to) the top or bottom mounting studs should tell the tale.

 

[Alpine 1789]

Do you have a set of DCOEs? It was obvious when they were put on the studs, as the centers didn't line up. I managed to fabricate a linkage that worked well enough that I forgot all about it after they were installed. The other thing is that as I recall, you could also tell just by measuring the distance from the edge of the casting to the top edge of the threaded hole. I am not near it now, otherwise I would post a photo so you could see the difference.

 

[RootesRich]

Do you have a set of DCOEs?

Sadly, no. My plan was to buy your set really cheap when you gave upon them, but once again you foiled my plans...