Paul,
I'll stand by my original statement(s). And not just in the case of
supercharging an engine.
ANYTIME you up the HP output on ANY engine, it needs to be strengthened.
And I will do that even with a competition engine. If I can figure a way
to increase the output, I'll also look for some way to increase it's
strength. Basically because I'm lazy. I do not get off rebuilding engines
(or writing them off) for a reason I could have forseen.
All the HP in the world is totally useless if the engine is a grenade
looking for a place to go off. For a street engine, reliablility should
be foremost in the builders mind. If, as in the case in question, an
increase in output is considered, an increase in the strength of the
engine is a requirement, if the original reliablility or at least a
semblence, is to be retained.
And in case anyone wants to bring up the "point" that you can get around
this by not driving the "hot" motor hard, I ask you, what's the purpose
of tuning it, if not to make use of the increased output.
Remember, too, when you're comparing HP figures, you are also using two
different measuring criteria. (see all the earlier posts, ad nauseum, on
this subject).
Rick Morrison
72 MGBGT
74 Midget
On Tue, 24 Nov 1998 00:22:55 -0500 "Paul A. Tegler, Jr"
<wizardz@amdyne.net> writes:
>...hate to single you out Rick..but not all needs to be replaced
>older (63 to 69) B's put out about 20 more HP than post 75's
>due to cam detuning to meet emissions here in the states
>the 1800 (18V) is quite comfortable putting out 120HP
>post 75's are rated somewhere around 75HP
>while earlier models are rated at 94HP
>a 4-6 pound boost would add about 25% to the power
>this only brings it back up to around 93.5 HP.
>Sure! too much boost would rip an 1800 up.
>What does a 1934cc big bore do to it!
>a mild boost just to get back the 20 or so HP lost to piston
>ring friction and suction work would be great!
>-----Original Message-----
>From: Rick Morrison <gofastmg@juno.com>
>To: eric@erickson.on.net <eric@erickson.on.net>
>Cc: mgs@autox.team.net <mgs@autox.team.net>
>Date: Monday, November 23, 1998 10:48 PM
>Subject: Re: Supercharging an MGB
>
>
>>
>>On Tue, 24 Nov 1998 03:19:00 +0000 Eric Erickson
><eric@erickson.on.net>
>>writes:
>>>Mike Gigante wrote:
>>>>
>>>> High Performance Products (Hans Pedersen) has a modern
>supercharger
>>>> kit for a B (and A series as well).
>>>>
>>>
>>>That's done it!
>>>
>>>I am planning a leisurely drive across from Adelaide to Melbourne
>soon
>>>(via the coast which must make it close to 800 kilometres or so?) so
>
>>>it
>>>looks like I should look this guy up. Any ideas on a price for the
>>>kit?
>>>
>>>Meanwhile, can anyone tell me what I would need to strengthen if I
>was
>>>
>>>to supercharge a 30 year old engine/vehicle?
>>
>>Every thing from the head studs/nuts to the sump bolts and from the
>>flywheel to the harmonic damper.
>> Look at it this way. You are going to increase the output of the
>engine
>>by 10-20%. If you were to get this increase in any other way (ie
>radical
>>cams, head, pistons etc,etc) you would make every part as strong as
>>possible. Same thing here.
>> The lower end of the engine needs to be as bullet proof as you can
>make
>>it. This will mean spending some $$$$. ARP rod bolts and main cap
>bolts;
>>have the rods magnafluxed, straightened and shot peened. Crankshaft
>>should be shotpeened also. as well as measured and re-ground as
>needed
>>(no out of round journals,etc). ALL journal shoulders should be
>radiused.
>>ANY part that is questionable should be replaced with new, preferebly
>>with aftermarket competition equipment.
>> On the top end, have the block "decked", with the minimum cut
>neccessary
>>to level. Likewise the head. Remove no more metal than needed to true
>it
>>up. ARP head studs and hardened, ground washers. Undercut the stud
>holes
>>in the block before installin the new studsInstall new hardened
>exhaust
>>seats; have a good 3 angle valve job done. Phospher bronze guides,
>>correctly sized and fitted.
>>
>>This should get you started.
>>
>>Remember, "Speed cost money. How fast do you want to go?"
>>
>>
>>Rick Morrison
>>72 MGBGT
>>74 Midget
>>
>>
>>>My recent dashing around the countryside has left the little yellow
>>>beast sounding a bit ragged around the edges as I think I pushed her
>a
>>>bit hard - so would the supercharger just give me the ability to
>>>really
>>>tear her apart at the seams?
>>>
>>>BTW I am hoping the noise is purely exhaust (I haven't had time to
>>>even
>>>look properly yet) as I had already half crushed one of the pipes on
>
>>>an
>>>errant rock or speed hump on the weekend so it may have given up the
>>>ghost on some of the even rougher roads at speed.
>>>
>>>Or maybe it was that slow cat...?
>>>
>>>Eric
>>>'68 MGB MkII
>>>
>>
>
>
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