1905 engine ?

[slak]

Has anybody built or heard of anybody that has built a 1905 engine
82mm stroke 86mm bore ?
i have done some calculations and it is possible just wanna know if anybody's done it

[Tony Z]

whats the point? It will cost much more than a standard type 1915cc and make less power. Will also be more difficult to build and if you dont get custom pistons made, it will be so wide it wont fit in the engine bay...

[slak]

Thanx for the feedback Tony
won't really cost that much as i have some parts to be able to build it got a oetinger crank H beam rods block
the most expensive thing will be the wbx bearings and getting the block linebored for it
std sleeves bored to 86mm there are a couple of pistons i can use that are off the shelf nissan or opel

why would u say that it would have less power do u mean hp or torq ?
not looking for a high reving drag motor just a motor with torq

[Tony Z]

as a thumb suck, without thinking about it (thanks to a few beers tonight), if you are aiming at less then 100hp it will be a good engine, with plenty low down torque.
a little port work and chamber work will do it nicely.

If you looking for bigger hp, then your cylinders are too small. Remember, bigger cylinders allow bigger valves and bigger airflow. The more air you get, the more power you have. small cylinders mean small valves and less airflow. For a daily driver that your mother will drive (drive like a granny - sorry), it will be good, but if you wanting to go the route of building an engine that takes so much effort, then you will probably be looking for a little more, and thats what you wont find.

[4agedub]

I have bult a couple of 1914cc engines.... it is a perfect combo due to the short stroke. This setup can rev to the moon and makes plenty torque.

The piston on a 69mm crankshaft will do 2716 feet / minute at 6000rpm , where the piston on a 82mm crankshaft will do 3228 feet / minute at the same RPM.

[slak]

Thanx 4agedub
don't think it will see 6000rpm
so will the longer stroke just lower the powerband because of piston speed ?
if so should u,r choice of cam be std or std with higher ratio rockers ?
i'd like to give it a go with the std sleeves and c what happens if it happens to be k@k
then i wasted some time , then just go to bigger sleeves and heads later
but if it's got lots of torq then i'll leave it as is

[4agedub]

The longer stroke in my experience makes the engine rough... it's simply not as smooth anymore. Also the bigger piston does generate a lot more torque.

The cam choise depends on what you want to do with the engine. Personally I like the scat c55 camshaft as it comes in real early and lasts up to about 6500rpm with a set of 1.25:1 ratio rockers. The c55 is a winner even for a mild street engine. Even the c65 would be ok... but the c65 use std rockers.

The other thing that I have experienced is that the engine temperature seems real happy in a 1914cc... even compared to a 1776cc. On my race car I've run with a 1776cc, 1914cc and a 2165cc before. The 1914cc ran the coolest out all all the engine combo's with the same cooling system and around the same compression ratio.

[slak]

rough have u seen my car ?

when u go to 82mm stroke does the cam get in the way as i'm sure things
get a little tight inside the block
i don't understand why cooling would be bad as the cooling tin would still fit perfectly and the sleeve
is not really that thin

[4agedub]

I think the cam will still clear with a 82mm crank... best would be to ask TonyZ

[Tony Z]

when u go to 82mm stroke does the cam get in the way as i'm sure things
get a little tight inside the block

You get cams that come pre-clearanced to avoid contact with the crank and rods, which can happen at higher stroke, not saying it will for you, but it might.
It will get tight inside the block. I hope you are ready to do some grinding and clearancing....

i don't understand why cooling would be bad as the cooling tin would still fit perfectly and the sleeve
is not really that thin

Is it? Do you honestly think that by making your engine approx 13mm wider the fanhousing will actually fit onto the cylinder tin without 7mm gaps on either side. Also remember, the tin isnt horizontal, it slopes, so you will have a gap the full width of the engine where the fan housing meets the cylinder tin.



Have you put more thought into this than just grabbing a crank and fitting it?
Clearancing the case is a effort that isnt to be underestimated. And welding magnesium to repair a hole you punched in the block is very costly.
Are you going to use 40 year old conrods or are you going to upgrade? At least, you need to improve the rod bolts.
Pushrods... cant use stock, they will be too short
new cam.... needs new lifters
HD valve springs to handle the cam
If you are moving the pistons out by 7mm on each side (you are talking about using stock pistons), how much support do you think you are loosing where they mate to the case.
Are the head studs long enough? They should be, but might not be.
will your exhaust still fit?

I am not trying to be negative, but you really need to consider all of this. In my opinion, you need a lower deck piston. You are going to so much effort, get a set of 90.5s made for the 82mm crank and you'll be much better off.

[slak]

have been giving it alot of thought
the pistons i want to use have a 32mm compression height
STD compression height is 39.44mm
and the skirt is 10mm shorter than the original t1 piston
so i'm not using spacers or shims to move the sleeves out i am using a shorter pistons to keep sleeve close to the block with little or no shims
i have a new set of H beam con rods ,don't have any 40 year old ones
push rods chrome moly ones yip got a set
i was going to build a 76mm stroker but my crank got lost so i collected most of the parts already
so i'm just going to use a longer stroke crank

the cam is actually the part i need to get right as the engine i'v got now, runs nice but i
need the power lower down in the rev range because my car's tyres are so big it brings the ratio down alot
for a std car with std tyres it would go like hell
that is why i want a longer stroke to get more torq but i think the cam will make or break this engine

[Tony Z]

Engle 100 for nothing but torque
Engle 110 for a little more (the "stock" engine characteristics with an 82mm crank)
Engle 120 for more power up top

Sounds like you have done a bit of homework. Make sure your pistons can fit your rods. Otherwise have the rods bushed to accept them.
I personally would run the 110 cam with 1.25 rockers if you looking for good grunt.

[slak]

yip homework was done
pin size is 22mm same as std piston
Bugger also advised me not to have a cam reground but to buy an original billet cam
does the piston speed and cam have any efect on each other like making the cam
to start working earlier in the rev range or later depending on stroke ?

[Tony Z]

you dont want more than 6000rpm, so dont worry about piston speed.
Its the engine capacity and breathing ability of the engine that effects the rpm range of the cam.

[slak]

Do U think it is a good idea to enlarge the valves and port heads
or stay with std size and port the heads
my original plan was to put 40mm in and 36mm ex in