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Re: O/T Tuning single DCOE on J15 engine

To: datsunmike <>,
Subject: Re: O/T Tuning single DCOE on J15 engine
From: Ronnie Day <>
Date: Tue, 03 Aug 2004 19:54:35 -0500
> Mike:

> I brought an old Honda Civic with a single Weber sidedraught to a shop that
> worked on Italian cars and they were able to sort out the running problems I
> was experiencing. Not cheap but not too bad considering all the needles and
> whatnot I would have had to buy to make it run well. They had everything
> they needed on their shelves.

That's basically what I did with the 510 when we came back to San Antonio
from Honolulu. I was TDY in Houston and happened on a big BAP store and
stopped in to see if they had a decent jet/choke/e-tube selection. Boy, did
they! A tuner's dream.

One of the counter guys and I spent most of one day tweaking the jetting and
did get the car to at least run and idle okay, in late summer. However, as I
mentioned before since the manifold bypassed the cooling system and when the
weather turned cold, the car just wouldn't run. Bottom line, while it looked
cool, I doubt the engine produced as much power with the single Weber as it
did with the downdraft Hitachi, which admittedly had be "smoothed"
considerably, rejetted and the secondary circuit tweaked somewhat.

I still think that for a daily driver of any type that SUs are a better
choice than a pair of DCOE type sidedrafts, and neither as as good as
properly setup EFI, which has a lot to do with the popularity of the KA24
and SR20 swaps. However if we EVER get settled and get our shop up I
definitely intend to run an A/B dyno comparison between twin SUs and dual 40
DCOEs on an L-18. I have a complete new, never installed, L-4 38mm SU setup
and a Warneford twin dual throat sidedraft manifold plus four 40 DCOEs.

BTW, I found the Holley/Weber tuning sheet that I transcribed from an
Edelbrock Holley jet block kit, and I already sent it to Marc and Adam. I
have it in both Word (cross platform) and AppleWorks for Mac types who don't
have Word. I'd be happy to send it to those who want it since the list serve
strips attachments. Be aware, though, that the Word file is close to 1 meg
and the AWorks file is around 2.5 meg.


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