Aussieveedubbers · Tech Talk

Stroker question

https://forums.aussieveedubbers.com/threads/64179/stroker-question

kombiute ·

Hello,

I've just received my alloy Empi Bubble top case ready for a stroker crank

details are as follows:

EMPI H.D SuperStroker Engine Case - 90.5/92mm Bore - Stroker Clearanced - Bubble Top and Full-Flow Oiling - 2 Shuffle Pins on center main - 10mm Inserts - Filled behind #3

I'm now in the market to purchase all the bits from crank, cam, pistons etc and wanted to go the 90.5 pistons & B's. I'm currently running 40 idf webbers, and am going a c45 cam and I have my eyo on a Scat or Empi counter weighted crank.

My question is, can I go with a standard set of rods? I have been told that I can, if my buider adjusts the deck height and uses shims, is this correct? If so, will I lose any performance? also, if their any need to go with Ratio Rockers? I again have been told they will add 15% performance, but are not neccessary.

I do allot of surf trips up and down the coast, so I want performance, together with reliability. I'm also throwing this into a 70 dual cap ute. Any guidance would be greatly appreciated.

Cheers

Bizarre ·

can I go with a standard set of rods? - depends on what crank you are going to run.
69mm - no problems. Then why would you have bought a bubble case
82mm - no way.

I think 76 and under you can get away with standard rods.

A rough rule of thumb is a 2:1 rod ratio.
69 crank has a 5.4" rod (137mm) ie 2:1

I think 5.7" is the longest you can get.

Have a read of some of the combos here
http://www.geocities.com/enginecookbook/menu.htm

Or go to www.aircooled.net and have a look at what makes up some of their long blocks

any need to go with Ratio Rockers? -
Depends if the cam you want says you can. They need to be designed for it.
Can put extra wear on the valve train.
Need to set the geometry of the rockers. ie custom cut push rods. Extra work that results in HP

56astro ·

82 stroke with std rods (5.394) is quite common for street engines.

82 stroke with an even shorter porsche (5.352") rod is also quite common for streeters.

std stroke with std rods gives a stroke ratio of almost 2:1 like Bizarre said. That is extremely long in the engine world - like many diesel engines. About 1.7:1 is as short as many builders recommend.

Go the the STF also, heaps of info there.
http://www.shoptalkforums.com/

Bizarre ·

Kombiute

The reason good engine builders are "good" is because they have experience.

Go through the Cookbook and click on all the 2L+ motors and have a look at the rod length.

Also have a read here
http://www.aircooled.net/gnrlsite/resource/articles/t1hpeng.htm
and go down to "Connecting Rod Length"

Bloody confusing if you ask me

:beer

vw54 ·

where u at Kombiute ???

Bizarre ·

He is in Sydney (east)

kombiute ·

Thank you for the information! It's greatly appreaciated, VW54 I'm in the eastern suburbs of Sydney, why can you help with the build ? have you got a shop?

I will have a read on the suggested threads.

Thanks again!

vw54 ·

I suggest that you talk with someone at a Shop who knows how to build a decent engine otherwise your wasting alot of funds

56astro ·

http://www.shoptalkforums.com/viewtopic.php?t=107350

Read, read, read, read, read.