Lotus Elan

1700cc in a stock twin cam block

PostPost by: garyeanderson » Tue Jan 11, 2005 2:12 pm

Truely the best of both worlds is a 1700cc in the stock twin cam
block. 1600 cc crank with the 3.06 stroke from Dave Bean or any of
the othe suppliers or just a reground Cortina crank with custom
pistons, .030" or .040" over from JE or Bean with a pin hight of 1.43
to 1.46 inches. The money spent is worth the 10 cubic inches and just
keep the revs under 7k and theres not much to go wrong. The block
will probably need some releaving at the bottom of the bores for rod
clearence and maybe a little on the jackshaft. The money spent doing
it this way is small and the rewards are a nice 145+ hp and 130 lb/ft
of torque with the the reqround cams with .380" to .410" lift and 285
degrees duration. If I were Les and wanted to do the Zetec swap I
would not stop at 170hp as this just has to much custom fabrication
to achieve such a limited gain over the modified twin cams power.
This modification works well with a Weber or Stromberg head and could
be done for about $3k USD doing most of the work yourself.

Gary Anderson

--- In ***@***.***, "rob_lamoreaux"
<[email protected]> wrote:
Seems to me that for a lot less than the Au$12000 mentioned you
could build

a nice 1700 twincam that would deliver a very streetable, reliable
150bhp

that would be very nice in an Elan without the concern of
overstressing the

engine or other parts. It would have a nice broad torque band,
still look

stock, and be driveable by most anyone. For another couple thousand
you

could add fuel injection and it would be as easy to use and
efficient as a

Zetec. Of course you wouldn't have the retarded (in degrees) idle
that dumps

fuel down the exhaust to keep the catalyst hot that a stock zetec
ECU has,

and you wouldn't be able to set the rev limiter over 7000, but
that's ok

with me.

My Elan with it's way to long a duration cam and stromberg carbs
isn't too

bad to start for a New Years Day drive even in 35 degree weather
after

sitting for a month. When I build up the weber engine in the
garage it will

have a .380"-.410" 285 degree cam which will be much nicer. If I
could add

the extra displacement of the tallblock it would be really really
really

nice without loosing the character of the car. But then I'm not
interested

in doing all the engineering Les described doing on his Zetec, when
I can do

a simple engine rebuild upgrading to a nice cam and get 95% of what
I want

in the car without going out of the autocross class I am currently
in. If I

went to a Zetec or even the tall block I'd be in a class with
either no

competition at an event, or cars I had no hope of beating without
also

adding fender flares and major changes that would make the car
unhappy on

the street. With the Weber engine I will have a nice street car
that will

have a better chance of beating the viper more than once a season.

And my Fiancee loves the Elan, both as a driver and a passenger. I
am sure

she will even help work on it like she has done for her dad on his
Alfas

(she helped put the tranny in the GTA Jr. twice last spring among
other

things). I just had to promise that some day she will have an Alfa
Romeo to

keep the Elan company in the garage. Of course the Alfa might have
to wait

until we do the addition on the house so that the Elan, Alfa and
Corvette

can be in the garage while the daily drivers sit in the driveway.
It is

Michigan after all, and I prefer not to have the nice cars sitting
under a

few feet of snow.

Just my outlook, for what works for me and my car.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
Cell (734)-604-9280
Email: [email protected]
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending
adventure.
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PostPost by: garyeanderson » Tue Jan 11, 2005 2:24 pm

I forgot to mention that this is with the later lip seal engines,
you will need a lip seal - rear seal housing and a lip seal oil pan
for the conversion on a rope seal engine. I think the rope seal oil
pickup should work with the later pan but you shold check it to make
sure.

--- In ***@***.***, "garyeanderson"
<[email protected]> wrote:

Truely the best of both worlds is a 1700cc in the stock twin cam
block. 1600 cc crank with the 3.06 stroke from Dave Bean or any of
the othe suppliers or just a reground Cortina crank with custom
pistons, .030" or .040" over from JE or Bean with a pin hight of
1.43

to 1.46 inches. The money spent is worth the 10 cubic inches and
just

keep the revs under 7k and theres not much to go wrong. The block
will probably need some releaving at the bottom of the bores for
rod

clearence and maybe a little on the jackshaft. The money spent
doing

it this way is small and the rewards are a nice 145+ hp and 130
lb/ft

of torque with the the reqround cams with .380" to .410" lift and
285

degrees duration. If I were Les and wanted to do the Zetec swap I
would not stop at 170hp as this just has to much custom fabrication
to achieve such a limited gain over the modified twin cams power.
This modification works well with a Weber or Stromberg head and
could

be done for about $3k USD doing most of the work yourself.

Gary Anderson

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PostPost by: lotuselanman » Wed Jan 12, 2005 9:34 am

Gidday Gary,
Between you and for Gawds sake don't let anybody else know. I am expecting a lot more than 170 HP but as a very conservative person I under quote.
Sworn to secrecy,
Les
----- Original Message -----
From: garyeanderson
To: ***@***.***
Sent: Wednesday, January 12, 2005 12:11 AM
Subject: Re: [LotusElan.net] 1700cc in a stock twin cam block



Truely the best of both worlds is a 1700cc in the stock twin cam
block. 1600 cc crank with the 3.06 stroke from Dave Bean or any of
the othe suppliers or just a reground Cortina crank with custom
pistons, .030" or .040" over from JE or Bean with a pin hight of 1.43
to 1.46 inches. The money spent is worth the 10 cubic inches and just
keep the revs under 7k and theres not much to go wrong. The block
will probably need some releaving at the bottom of the bores for rod
clearence and maybe a little on the jackshaft. The money spent doing
it this way is small and the rewards are a nice 145+ hp and 130 lb/ft
of torque with the the reqround cams with .380" to .410" lift and 285
degrees duration. If I were Les and wanted to do the Zetec swap I
would not stop at 170hp as this just has to much custom fabrication
to achieve such a limited gain over the modified twin cams power.
This modification works well with a Weber or Stromberg head and could
be done for about $3k USD doing most of the work yourself.

Gary Anderson

--- In ***@***.***, "rob_lamoreaux"
<[email protected]> wrote:
Seems to me that for a lot less than the Au$12000 mentioned you
could build

a nice 1700 twincam that would deliver a very streetable, reliable
150bhp

that would be very nice in an Elan without the concern of
overstressing the

engine or other parts. It would have a nice broad torque band,
still look

stock, and be driveable by most anyone. For another couple thousand
you

could add fuel injection and it would be as easy to use and
efficient as a

Zetec. Of course you wouldn't have the retarded (in degrees) idle
that dumps

fuel down the exhaust to keep the catalyst hot that a stock zetec
ECU has,

and you wouldn't be able to set the rev limiter over 7000, but
that's ok

with me.

My Elan with it's way to long a duration cam and stromberg carbs
isn't too

bad to start for a New Years Day drive even in 35 degree weather
after

sitting for a month. When I build up the weber engine in the
garage it will

have a .380"-.410" 285 degree cam which will be much nicer. If I
could add

the extra displacement of the tallblock it would be really really
really

nice without loosing the character of the car. But then I'm not
interested

in doing all the engineering Les described doing on his Zetec, when
I can do

a simple engine rebuild upgrading to a nice cam and get 95% of what
I want

in the car without going out of the autocross class I am currently
in. If I

went to a Zetec or even the tall block I'd be in a class with
either no

competition at an event, or cars I had no hope of beating without
also

adding fender flares and major changes that would make the car
unhappy on

the street. With the Weber engine I will have a nice street car
that will

have a better chance of beating the viper more than once a season.

And my Fiancee loves the Elan, both as a driver and a passenger. I
am sure

she will even help work on it like she has done for her dad on his
Alfas

(she helped put the tranny in the GTA Jr. twice last spring among
other

things). I just had to promise that some day she will have an Alfa
Romeo to

keep the Elan company in the garage. Of course the Alfa might have
to wait

until we do the addition on the house so that the Elan, Alfa and
Corvette

can be in the garage while the daily drivers sit in the driveway.
It is

Michigan after all, and I prefer not to have the nice cars sitting
under a

few feet of snow.

Just my outlook, for what works for me and my car.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
Cell (734)-604-9280
Email: [email protected]
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending
adventure.









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PostPost by: rgh0 » Wed Jan 12, 2005 10:03 am

--- In ***@***.***, "garyeanderson"
<[email protected]> wrote:

Truely the best of both worlds is a 1700cc in the stock twin cam
block.


Gary
There is no substitute for cubic inches as the saying goes and it is
almost always cheaper to go for more capacity at lower revs than its
equivalent of less capacity at higher revs. Choosing revs versus
capacity is a decision based on cost, competition classes and
originality desires. For a street engine or a competiton class that
allows it I would always go for the biggest bore and stroke
combination allowed and practical.


doing it this way is small and the rewards are a nice 145+ hp and
130 lb/ft

of torque with the the reqround cams with .380" to .410" lift and
285

degrees duration.

Certainly the 145+ hp and 130 ft/bs is available under 7000 rpm with
this 1700 cc bottom end combination but the costs start to add up if
starting with a good condition standard twin cam that you do all the
dissassembly and reassembly on. If you dont do the all head work
below you will not get the 145 hp. Without the big valves, carb
exhaust mods and matching porting you run into a head breathing limit
around 140 hp below 7000 rpm no matter what cam you put in or how
much capacity you put below the head. That limit will be maybe 5 to
10 hp lower again on a Stromberg versus a Weber head. You will get
about 3 hp more in the long stroke 1700 conversion versus the same
head mods in a standard stroke 1600 cc engine and it will come in at
slightly lower revs and have a slighly better torque curve across the
rev range. Maybe get a bit more than extra 3 hp if you optimised the
cam for 1700cc long stroke engine but hard to do as a huge range of
cams is not available

Total list of mods for 145 plus hp 1700 cc engine at 7000 rpm limit

1. 1600 Crank, second hand
2. New main and big end bearings
3. Long Rods, second hand top bush checked and resized
4. New 12 point rod bolts ( a must for 7000 rpm limit)
5. New 83.5 mm pistons and rings for 10.5 comp ratio and 1700 cc,
cast Ok but forged desirable and not that much more expensive.
6. Block rebore to 83.5 mm
7. New 85mm head gasket
9. Bottom end gasket set
10. Water pump rebuild kit ( crazy not to do with the engine out)
11. New large 1.62 inlet and 1.4 exhaust valves
12. New high lift spring kit ( springs, seats, retainers, collets).
Need to select the right kit to avoid having to deepen the spring
pockets which is expensive and risky.
13. New steel, thin bucket followers and any needed new shims
14. Porting and flow bench testing the head
15. Larger bore headers,tail pipe and muffler
16. 34 mm chokes in 40 DCOE's or ideally 36 mm chokes in 45 DCOEs
plus dyno tuning to set them up properly
17. Possibly a replacement of your distributor advance springs to get
a quicker curve depending on the actual dizzy you have and fuel you
are using, again generally requires dyno tuning to set properly
18. New or reground cams. A .45 lift cam can be fitted for same cost
and will be better than a .41 lift cam and much better than a .380
lift cam.
19. New timing chain ( again crazy not to put new chain in when
rebuild an engine)
20. Oil and filters for running in filter change, fresh antifreeze.
21. Sump and mods to sump and rear seal carrier if have early rope
seal engine. Need to modify baffling in later sumps to suit earlier
oil pick up location.
22. Anything else you find wrong with the base engine when you pull
it apart.

be done for about $3k USD doing most of the work yourself.

When you add up the above I think you will be around US$5K or A$8k.
Only way to bring down cost significantly is if you can do the
porting and flow bench testing yourself as this is a time consuming
and expensive process to pay for.



regards
Rohan
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PostPost by: rgh0 » Wed Jan 12, 2005 10:22 am

--- In ***@***.***, "Rohan Hodges" <[email protected]> wrote:


Total list of mods for 145 plus hp 1700 cc engine at 7000 rpm limit

3. Long Rods, second hand top bush checked and resized


Sorry made a mistake on my list - you dont need new rods can use the
standard Lotus rods with low compression height pistons. I was
thinking of the tall block conversion.

Rohan
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PostPost by: lotuselanman » Wed Jan 12, 2005 10:48 am

Gidday Rohan,
1600 crank and rods in a 1500 block? What are the pistons.
Surely a 711 type block,crank and rods with standard or + over pistons for 1700cc ?
Trust this is not cheating for class ?
See ya, Les
----- Original Message -----
From: Rohan Hodges
To: ***@***.***
Sent: Wednesday, January 12, 2005 8:01 PM
Subject: Re: [LotusElan.net] 1700cc in a stock twin cam block



--- In ***@***.***, "garyeanderson"
<[email protected]> wrote:

Truely the best of both worlds is a 1700cc in the stock twin cam
block.


Gary
There is no substitute for cubic inches as the saying goes and it is
almost always cheaper to go for more capacity at lower revs than its
equivalent of less capacity at higher revs. Choosing revs versus
capacity is a decision based on cost, competition classes and
originality desires. For a street engine or a competiton class that
allows it I would always go for the biggest bore and stroke
combination allowed and practical.


doing it this way is small and the rewards are a nice 145+ hp and
130 lb/ft

of torque with the the reqround cams with .380" to .410" lift and
285

degrees duration.

Certainly the 145+ hp and 130 ft/bs is available under 7000 rpm with
this 1700 cc bottom end combination but the costs start to add up if
starting with a good condition standard twin cam that you do all the
dissassembly and reassembly on. If you dont do the all head work
below you will not get the 145 hp. Without the big valves, carb
exhaust mods and matching porting you run into a head breathing limit
around 140 hp below 7000 rpm no matter what cam you put in or how
much capacity you put below the head. That limit will be maybe 5 to
10 hp lower again on a Stromberg versus a Weber head. You will get
about 3 hp more in the long stroke 1700 conversion versus the same
head mods in a standard stroke 1600 cc engine and it will come in at
slightly lower revs and have a slighly better torque curve across the
rev range. Maybe get a bit more than extra 3 hp if you optimised the
cam for 1700cc long stroke engine but hard to do as a huge range of
cams is not available

Total list of mods for 145 plus hp 1700 cc engine at 7000 rpm limit

1. 1600 Crank, second hand
2. New main and big end bearings
3. Long Rods, second hand top bush checked and resized
4. New 12 point rod bolts ( a must for 7000 rpm limit)
5. New 83.5 mm pistons and rings for 10.5 comp ratio and 1700 cc,
cast Ok but forged desirable and not that much more expensive.
6. Block rebore to 83.5 mm
7. New 85mm head gasket
9. Bottom end gasket set
10. Water pump rebuild kit ( crazy not to do with the engine out)
11. New large 1.62 inlet and 1.4 exhaust valves
12. New high lift spring kit ( springs, seats, retainers, collets).
Need to select the right kit to avoid having to deepen the spring
pockets which is expensive and risky.
13. New steel, thin bucket followers and any needed new shims
14. Porting and flow bench testing the head
15. Larger bore headers,tail pipe and muffler
16. 34 mm chokes in 40 DCOE's or ideally 36 mm chokes in 45 DCOEs
plus dyno tuning to set them up properly
17. Possibly a replacement of your distributor advance springs to get
a quicker curve depending on the actual dizzy you have and fuel you
are using, again generally requires dyno tuning to set properly
18. New or reground cams. A .45 lift cam can be fitted for same cost
and will be better than a .41 lift cam and much better than a .380
lift cam.
19. New timing chain ( again crazy not to put new chain in when
rebuild an engine)
20. Oil and filters for running in filter change, fresh antifreeze.
21. Sump and mods to sump and rear seal carrier if have early rope
seal engine. Need to modify baffling in later sumps to suit earlier
oil pick up location.
22. Anything else you find wrong with the base engine when you pull
it apart.

be done for about $3k USD doing most of the work yourself.

When you add up the above I think you will be around US$5K or A$8k.
Only way to bring down cost significantly is if you can do the
porting and flow bench testing yourself as this is a time consuming
and expensive process to pay for.



regards
Rohan








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PostPost by: rgh0 » Wed Jan 12, 2005 11:20 am

--- In ***@***.***, "Les Mellor" <[email protected]>
wrote:
Gidday Rohan,
1600 crank and rods in a 1500 block? What are the pistons.
Surely a 711 type block,crank and rods with standard or + over
pistons for 1700cc ?

Trust this is not cheating for class ?
See ya, Les


Les
You can do it, just need special low compression height pistons so
the pistons dont come out the top of the blockwith the long stroke
crank. Enough bore length at the bottom of the block for the piston
to go down at the bottom of the stroke.

Unfortunately stroke mods not allowed in my Group Sb Historic racing
as you must keep the stroke standard and max of 1.5 mm overbore. I
run 83.5 mm bore and standard stroke for 1600 cc and have my engines
offically measured and sealed so I dont get protested. I think I am
one of the few strictly legal cars in my class !!

You can get the long stroke out of a Datsun L18 if you want rather
than a standard 1600 ford crank. This is a beautiful 8
counterweighted forging good for more revs than anything else you can
build into a twin cam , even better than the Datsun L16 crank you use
for standard stroke which has only 4 counterweights like the ford
cranks.

In reality I dont need more than 1600cc in my engines to get near
enough to the head breathing limit at around 8000 rpm.

Rohan
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PostPost by: garyeanderson » Wed Jan 12, 2005 12:27 pm

Hi Rohan

Your reply is certainly more in depth than mine. Yes the 145 hp
was a little optimistic with the .380" lift cams but I think that
most of the rest could be done for the $3k without touching the head
much. 135 hp with a near stock top end would be about right but the
torque number would be about the same (130ish).I was just trying to
demonstrate that engine swaps are not the only way to go and power
increases that you can feel and don't have to be in the 8k to 10k
plus neighborhood.

Gary

--- In ***@***.***, "Rohan Hodges" <[email protected]> wrote:

--- In ***@***.***, "garyeanderson"
<[email protected]> wrote:
>
> Truely the best of both worlds is a 1700cc in the stock twin
cam

> block.


Gary
There is no substitute for cubic inches as the saying goes and it
is

almost always cheaper to go for more capacity at lower revs than
its

equivalent of less capacity at higher revs. Choosing revs versus
capacity is a decision based on cost, competition classes and
originality desires. For a street engine or a competiton class
that

allows it I would always go for the biggest bore and stroke
combination allowed and practical.


> doing it this way is small and the rewards are a nice 145+ hp and
130 lb/ft
> of torque with the the reqround cams with .380" to .410" lift and
285
> degrees duration.

Certainly the 145+ hp and 130 ft/bs is available under 7000 rpm
with

this 1700 cc bottom end combination but the costs start to add up
if

starting with a good condition standard twin cam that you do all
the

dissassembly and reassembly on. If you dont do the all head work
below you will not get the 145 hp. Without the big valves, carb
exhaust mods and matching porting you run into a head breathing
limit

around 140 hp below 7000 rpm no matter what cam you put in or how
much capacity you put below the head. That limit will be maybe 5 to
10 hp lower again on a Stromberg versus a Weber head. You will get
about 3 hp more in the long stroke 1700 conversion versus the same
head mods in a standard stroke 1600 cc engine and it will come in
at

slightly lower revs and have a slighly better torque curve across
the

rev range. Maybe get a bit more than extra 3 hp if you optimised
the

cam for 1700cc long stroke engine but hard to do as a huge range of
cams is not available

Total list of mods for 145 plus hp 1700 cc engine at 7000 rpm limit

1. 1600 Crank, second hand
2. New main and big end bearings
3. Long Rods, second hand top bush checked and resized
4. New 12 point rod bolts ( a must for 7000 rpm limit)
5. New 83.5 mm pistons and rings for 10.5 comp ratio and 1700 cc,
cast Ok but forged desirable and not that much more expensive.
6. Block rebore to 83.5 mm
7. New 85mm head gasket
9. Bottom end gasket set
10. Water pump rebuild kit ( crazy not to do with the engine out)
11. New large 1.62 inlet and 1.4 exhaust valves
12. New high lift spring kit ( springs, seats, retainers, collets).
Need to select the right kit to avoid having to deepen the spring
pockets which is expensive and risky.
13. New steel, thin bucket followers and any needed new shims
14. Porting and flow bench testing the head
15. Larger bore headers,tail pipe and muffler
16. 34 mm chokes in 40 DCOE's or ideally 36 mm chokes in 45 DCOEs
plus dyno tuning to set them up properly
17. Possibly a replacement of your distributor advance springs to
get

a quicker curve depending on the actual dizzy you have and fuel you
are using, again generally requires dyno tuning to set properly
18. New or reground cams. A .45 lift cam can be fitted for same
cost

and will be better than a .41 lift cam and much better than a .380
lift cam.
19. New timing chain ( again crazy not to put new chain in when
rebuild an engine)
20. Oil and filters for running in filter change, fresh antifreeze.
21. Sump and mods to sump and rear seal carrier if have early rope
seal engine. Need to modify baffling in later sumps to suit earlier
oil pick up location.
22. Anything else you find wrong with the base engine when you pull
it apart.

> be done for about $3k USD doing most of the work yourself.

When you add up the above I think you will be around US$5K or A$8k.
Only way to bring down cost significantly is if you can do the
porting and flow bench testing yourself as this is a time consuming
and expensive process to pay for.



regards
Rohan
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PostPost by: "e s" » Wed Jan 12, 2005 5:58 pm

Not to encourage the engine swappers, but after all this you still have a 30000 mile motor, same short valve guides, without seals, same old cast iron, same press in water pump and poor head draining, leaks leaks leaks.

A tall block doesn't really fit under the hood, so you either have to lowerit a smidge or crack your hood[bonnet] or do some glass work.

Of course the zetek is even worse

I always advise people to get the car right and drive it, if you still feelthe need for more hp, go for it. How many projects have you seen in the garage for 10 years, whenthey could have been driving it in a week? Some people want the project, not the car.


A .06 over twin cam is about 1600cc, shave the head and put your big valvesin and you've got your 126 hp.

now how many dollars per hp is it above that?
----- Original Message -----
From: garyeanderson <***@***.***>
To: ***@***.***
Subject: Re: [LotusElan.net] 1700cc in a stock twin cam block
Date: Wed, 12 Jan 2005 12:27:34 -0000



Hi Rohan

Your reply is certainly more in depth than mine. Yes the 145 hp
was a little optimistic with the .380" lift cams but I think that
most of the rest could be done for the $3k without touching the head
much. 135 hp with a near stock top end would be about right but the
torque number would be about the same (130ish).I was just trying to
demonstrate that engine swaps are not the only way to go and power
increases that you can feel and don't have to be in the 8k to 10k
plus neighborhood.

Gary

--- In ***@***.***, "Rohan Hodges" <[email protected]> wrote:
>
> --- In ***@***.***, "garyeanderson" <[email protected]> wrote:
> > > Truely the best of both worlds is a 1700cc in the stock twin
cam
> > block. Gary
> There is no substitute for cubic inches as the saying goes and it
is
> almost always cheaper to go for more capacity at lower revs than
its
> equivalent of less capacity at higher revs. Choosing revs versus
> capacity is a decision based on cost, competition classes and
> originality desires. For a street engine or a competiton class
that
> allows it I would always go for the biggest bore and stroke
> combination allowed and practical. > doing it this way is small
> and the rewards are a nice 145+ hp and 130 lb/ft > of torque with
> the the reqround cams with .380" to .410" lift and 285 > degrees
> duration. Certainly the 145+ hp and 130 ft/bs is available under
> 7000 rpm
with
> this 1700 cc bottom end combination but the costs start to add up
if
> starting with a good condition standard twin cam that you do all
the
> dissassembly and reassembly on. If you dont do the all head work
> below you will not get the 145 hp. Without the big valves, carb
> exhaust mods and matching porting you run into a head breathing
limit
> around 140 hp below 7000 rpm no matter what cam you put in or how
> much capacity you put below the head. That limit will be maybe 5
> to 10 hp lower again on a Stromberg versus a Weber head. You will
> get about 3 hp more in the long stroke 1700 conversion versus the
> same head mods in a standard stroke 1600 cc engine and it will
> come in
at
> slightly lower revs and have a slighly better torque curve across
the
> rev range. Maybe get a bit more than extra 3 hp if you optimised
the
> cam for 1700cc long stroke engine but hard to do as a huge range
> of cams is not available
>
> Total list of mods for 145 plus hp 1700 cc engine at 7000 rpm limit
>
> 1. 1600 Crank, second hand
> 2. New main and big end bearings
> 3. Long Rods, second hand top bush checked and resized
> 4. New 12 point rod bolts ( a must for 7000 rpm limit)
> 5. New 83.5 mm pistons and rings for 10.5 comp ratio and 1700 cc,
> cast Ok but forged desirable and not that much more expensive.
> 6. Block rebore to 83.5 mm
> 7. New 85mm head gasket
> 9. Bottom end gasket set
> 10. Water pump rebuild kit ( crazy not to do with the engine out)
> 11. New large 1.62 inlet and 1.4 exhaust valves
> 12. New high lift spring kit ( springs, seats, retainers,
> collets). Need to select the right kit to avoid having to deepen
> the spring pockets which is expensive and risky.
> 13. New steel, thin bucket followers and any needed new shims
> 14. Porting and flow bench testing the head
> 15. Larger bore headers,tail pipe and muffler
> 16. 34 mm chokes in 40 DCOE's or ideally 36 mm chokes in 45 DCOEs
> plus dyno tuning to set them up properly
> 17. Possibly a replacement of your distributor advance springs to
get
> a quicker curve depending on the actual dizzy you have and fuel
> you are using, again generally requires dyno tuning to set
> properly
> 18. New or reground cams. A .45 lift cam can be fitted for same
cost
> and will be better than a .41 lift cam and much better than a .380 liftcam.
> 19. New timing chain ( again crazy not to put new chain in when
> rebuild an engine)
> 20. Oil and filters for running in filter change, fresh antifreeze.
> 21. Sump and mods to sump and rear seal carrier if have early
> rope seal engine. Need to modify baffling in later sumps to suit
> earlier oil pick up location.
> 22. Anything else you find wrong with the base engine when you pull it apart.
>
> > be done for about $3k USD doing most of the work yourself.
>
> When you add up the above I think you will be around US$5K or
> A$8k. Only way to bring down cost significantly is if you can do
> the porting and flow bench testing yourself as this is a time
> consuming and expensive process to pay for.
>
>
>
> regards
> Rohan

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PostPost by: garyeanderson » Wed Jan 12, 2005 11:18 pm

Hi e s
A tall deck fits fine without the issues you state in my Elan S2
with a spyder frame, this combo isnt for everyone but it works for
me. Most of your concerns are non issues for me. Your .060" over Twin
cam is basicly the same money as 1700 long stroke engine plus what
ever you have to pay for the crankshaft.

Gary Anderson

--- In ***@***.***, "e s" <[email protected]> wrote:
Not to encourage the engine swappers, but after all this you still
have a 30000 mile motor, same short valve guides, without seals, same

old cast iron, same press in water pump and poor head draining,
leaks leaks leaks.

A tall block doesn't really fit under the hood, so you either have
to lower it a smidge or crack your hood[bonnet] or do some glass

work.

Of course the zetek is even worse

I always advise people to get the car right and drive it, if you
still feel the need for more hp, go for it. How many projects have

you seen in the garage for 10 years, whenthey could have been driving
it in a week? Some people want the project, not the car.


A .06 over twin cam is about 1600cc, shave the head and put your
big valves in and you've got your 126 hp.


now how many dollars per hp is it above that?
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PostPost by: elancoupe » Wed Jan 12, 2005 11:23 pm

you dont need new rods can use the
standard Lotus rods with low compression height pistons. I was
thinking of the tall block conversion.

Rohan
\



Correct. I have the 125e rods in my 1700 TC. I got the special
pistons from DBE for the short height stroker. They are Omega
pistons.

I have regular big valves, a mild port job on an ex C prod (SCCA)
head and 380 lift cams. On Dell'ortos with 34 mm chokes, my motor
dynoed at 139 HP and 133 Lb/ft of torque.


Mike B
66 S3 FHC RHD
Mike
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PostPost by: rgh0 » Thu Jan 13, 2005 11:05 am

> now how many dollars per hp is it above that?

Developing twin cams is very much a $ per HP equation with some clear
stages where big costs set in. The stages I consider are pretty much
like those in the DB catalogue ( he does know his stuff !)Also no
magic fixes to get the hp without the dollars as bigger bottom ends
dont really deliver much as most of limit and costs is in over coming
the head breathing limit.

stage 1 - rebuild to sprint spec 126 hp minimal cost above a standard
rebuild especially if you already have sprint cams

stage 2 - minimal mods but put in the highest lift cam you can into
the standard valve train. Limits you to around 135 hp in a 1600 or
1700 under 7000 rpm as the limit is head breathing. Cost above
standard rebuild around US$1000 for reground cams and little bit of
head work.

stage 3 - mods to make the head flow properly, which raise the
breathing limit in the head to around 180 to 190 hp - carbs ,
exhaust , cams, valves ,porting etc but result limited to around
150hp with standard 1600 bottom end and engine limit below 7000
rpm. A long stroke 1700 or tall block 1760 will get a little more (
but not much) below 7000 rpm with right cam. Costs start to really
kick in here around the US$5000 mark if you do most of the work. Most
of the cost relates to head work, a bigger bottom end does not cost
much, gives better torque but will not get much more hp.

stage 4 - mods to bottom end as well as head mods carried in stage
3. Rev limit to around 8500 rpm and compression ratio to around 12
to 1 to exploit the head breathing limit at around 180 hp with a .45
lift cam in 1600cc engine. The dollars really get big here with a
properly done engine around US$10,000 wih you doing most of the labor.

stage 5- beyond 180 hp, starting to get into exotic territory here in
any capacity engine. You will be heavily trading torque for top end
hp and higher peak revs and be using extreme cam profiles which
really hammer the valve gear. Head mods carried out to extreme limit
to get breathing capability up to around 200hp. To actually have a
quicker car lots of other issues such as gearing to deal with also.
If you have to ask the cost then you dont want to even think about
going here. Every engine is hand crafted masterpiece and has costs to
suit.


As you go up the HP scale each additional HP costs you more and more
dollars
Rohan
In God I trust.... All others please bring data
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