Mike;
Well it's encouraging to get at least one positive response. You may have
well hit the nail on the head with "do this with an experienced A-series
engine builder". That may be my problem, as I certainly am not an
experienced A-series builder. And here in the boondocks of Vermont I think I
would have to go many days travel to find such a one, though I would be glad
to be proved wrong. Anyone know of a shop that specializes in A-series in
New England? I would like to find someone whether I go with the 1380 or not.
BTW, when you say you've put a lot of miles on, how many is that? 5K? 50K?
Also, I haven't heard much about Longman heads. I see Mini Mania sells them,
but there isn't much performance data available on them other that valve
sizes. Any input?
<dnw>
1972 Midget
1998 Safari
1999 9-3
1964 (Me)
I enjoy long walks. Especially when they are taken by people who annoy me.
----- Original Message -----
From "Mike Gigante" <mikeg at vicnet.net.au>
To: "Gerard" <pixelsmith@gerardsgarage.com>; "David N Waldmann"
<david@vermonthardwoods.com>; <spridgets@autox.team.net>
Sent: Monday, March 11, 2002 5:55 AM
Subject: 1380cc motors
>
> I know some folks (David Riker?), have had problems have had problems
> with 1380cc engines.
>
> I also see that a lot of people are trying to talk
> folks out of doing it based on "lots of people had problems with
> bore flex etc".
>
> However, I have had two 1380cc motors, and apart from a poor
> quality assembly job on one of them (the oil pickup wasn't hot
> tanked with the rest of the engine and the resultant crud caused
> damage), I have not had any problems. I used both of these engines
> in competition, I have put a lot of miles on the 2nd one because in
> addition to the race track, I also have used it on navigation rallies,
> touring events, club drives and special stage rallies. I have gone
> from a 266 cam -> 286 cam to a race/rally cam (mid 290s duration,
> 0.5" total lift with 1.5 rockers)
> .
> I started with a Longman GT6 head but now have a killer 129 cfm head
> on the engine now.
>
> So, what I am saying is that it puts out good HP/torque, I have driven
> the tits off it on lots of events, and I have not had these bore-flex
> problems. I can say this with certainty because the engine has been pulled
> down and checked after loss of coolant on a rally ended up
> cracking the GT6 head. There was just no evidence.
>
> In its initial config, it had the Hepolite rings. After the rebuild
> I have gone to gapless rings (very happy about that).
>
> I *love* the 1380 motor. I wouldn't swap it for quids. It is one of
> the reasons that my bugeye is such a fun car to drive -- bags of torque
and
> excellent performance & responsiveness.
>
> Now, I'm not the only one either - there are quite a few successful
> big bore motors running around in competition here in Australia.
>
> I think what is true is that you should do this with an experienced
> A-series engine builder.
>
> Some other titbits:
>
> a) a very successful local engine builder now sonic tests all blocks
> that are to be used for big-bore projects (this includes the 72.5mm
> custom pistons he sometimes uses. This avoids starting with an
> inferior casting that can result in undersized walls. This is
> apparently not all that common, but you don't want to go there...
>
> b) The staggered offset bore as shown in older editions of Vizard is
> no longer in favour -- now the bore centers lie along the centerline
> but they are spread fore/aft to leave more metal b/n bores 2&3
>
> c) you might consider using the A+ block or at minimum use the
thick-flange
> spridget block.
>
> d) not many people do the 74mm engines by choice. Even if you have
> serious problems with the 73.5 bores, the 74 may not be able to
> recover good bores, so sometimes you just run out of luck...
>
> e) Some engine builders argue that max HP can be obtained with +0.040
> bores. I can well believe that, but the cost is more revs and a
> narrower power band. One of my race motors is +0.040", the other is
> +0.020". They both produce more HP than my race/rally 1380, but
> neither has the mid-range torque and thus the punch out of corners, and
> for a car to be driven on the street, that is what you really want.
>
> Mike
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