Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

GMH Starfire 1.9L 4cyl interest?

Started by _vk4akp_ , Aug 15 2012 09:03 PM

«
Prev

Next

Please log in to reply

188 replies to this topic

#151 _Bomber Watson_

Guests

Posted 10 November 2013 - 05:28 PM

I see. This is because opposing cylidners are on the opposing stroke and in all balance themselves out?

Meaning if a crank shaft is torsionally rigid enough the combo's you mentioned would not suffer from any kind of issue?

If this is the case, take the previously mentioned 3cyl engine, back to my original point (full circle, woot) why would they not just build a flat twin and be done with it instead of dicking around with balance shafts, witchcraft and quantum mechanics?

Edited by Bomber Watson, 10 November 2013 - 05:29 PM.

Back to top

#152 _oldjohnno_

Guests

Posted 10 November 2013 - 06:18 PM

The trouble is that anything that makes an engine shake tends to get thrown under the heading of "balancing". I think engine balance refers to the management of the rotating and reciprocating masses. But other things can make the engine shake too: torsional vibration of the crank for one, irregular or widely spaced power impulses is another. But they have nothing to do with balance.

A flat twin is nice and smooth, but not without its own problems. Packaging or the sheer bulk of it would be the main one. Inline engines are very compact, and this brings along other benefits like very compact manifolding (that can be integral to the head casting) and this in turn has other benefits such as a very quick cat-con light-off time. These are the things that make or break a production engine.

Back to top

#153 _Bomber Watson_

Guests

Posted 10 November 2013 - 06:21 PM

Right, so, what we learnt here is that the guys designing new engines are smarter than me.

Contrary to my thoughts.

Cool.

Back to top

#154 _oldjohnno_

Guests

Posted 10 November 2013 - 06:41 PM

Right, so, what we learnt here is that the guys designing new engines are smarter than me.

They're certainly a helluva lot smarter than me. Anyone can build a fast engine but it takes real brains to design one that's fast, clean, economical and fits into the space allocated.

Back to top

#155 _Bomber Watson_

Guests

Posted 10 November 2013 - 07:14 PM

Mate its taken me 12 months to tack up a swingarm for my KZ/CBR hybrid, so i know what your saying there.

Back to top

#156 _barana_

Guests

Posted 24 December 2013 - 08:18 PM

Hey Noballsuc

How did you go with ur starfire crank, rods pistons and pins, any improvement?

Back to top

#157 EunUCh

Lotsa Posts!

Members
2,769 posts

Location:not this planet
Car:japos
Joined: 23-November 06

Posted 25 December 2013 - 08:53 AM

Pretty well over it for now,the money and time spent on this thing made me think I should have put a six in it from the start.

So six it is,might go against the grain a bit and graft in an ecotec.

Back to top

#158 _Bomber Watson_

Guests

Posted 25 December 2013 - 09:17 AM

Back to top

#159 _barana_

Guests

Posted 25 December 2013 - 01:32 PM

Aiiiiiiiieeeeeeee

Back to top

#160 _barana_

Guests

Posted 25 December 2013 - 01:35 PM

Noballsuc:4 light pistons pins and rods would be the same or less than a 6.... And an sc12 supercharger would be cheaper than an ecotec transplant.

.
Well if ur really thinking of cancelling the project, could u possibly publish the measurements to make up that jIg to drill the pins so others can follow in ur footsteps?

Edited by barana, 25 December 2013 - 01:39 PM.

Back to top

#161 EunUCh

Lotsa Posts!

Members
2,769 posts

Location:not this planet
Car:japos
Joined: 23-November 06

Posted 31 December 2013 - 02:02 PM

Its OK Bomber,it will have the right number of cylinders and painted red no one will ever know the difference

This was just to see how close I would get to striking oil with a 5/8 hole

I didnt keep any records of measurements of jig,but I will measure it up when I get some more time,oldjonno is right about

being well under balanced and the Mallory I ordered that was advertised as the size I wanted ended up being

too big and there just isn't enough room to fit it,and it was tuff titties from the mob who supplied it.

Time and money spent could have gone into something else.

Back to top

#162 _big jack_

Guests

Posted 13 June 2014 - 04:35 PM

Got a question, I was talking to a bloke who told me his dad bought a 1982 Toyota Corona with a Starfire engine in it I've never heard of that one before. Is that right?

Thanks, John.

Back to top

#163 _Muzzy_

Guests

Posted 13 June 2014 - 05:11 PM

Got a question, I was talking to a bloke who told me his dad bought a 1982 Toyota Corona with a Starfire engine in it I've never heard of that one before. Is that right?

Thanks, John.

Yes that is correct, toyota moved from the 18rc 2lt engine to the star fire 4 in 81-82 to align with a model change ( 4 rectangle headlights) to about 84 when the next model was released which was a forerunner to the brilliant twin cam 2lt

Back to top

#164 rodomo

To advertise here, call 13TORANA

Members
18,030 posts

Name:R - O - B Dammit!
Location:Way out west of Melbourne Awstraylya
Joined: 10-December 05

Posted 13 June 2014 - 10:34 PM

You'll note somewhere on the tags an X. Maybe on the body badges too? The engine might have a decal 1X too from memory?
This was Toyota's way of telling everyone WE DIDN'T MAKE THIS DAMN ENGINE!

EDIT: XT 130 was the model

Attached Files

xt 130.jpg 51.43K 3 downloads
xt 130 engine.jpg 71.94K 5 downloads

Edited by rodomo, 13 June 2014 - 10:40 PM.

Back to top

#165 warrenm

Forum Fixture

Members
2,116 posts

Location:Central West NSW
Car:1972 LJ Torana
Joined: 08-November 05

View Garage

Posted 13 June 2014 - 10:35 PM

The motors were fitted to lift the Australian content.

Back to top

#166 _2ELCS_

Guests

Posted 13 June 2014 - 11:03 PM

The gang's all here ?

Back to top

#167 _big jack_

Guests

Posted 14 June 2014 - 08:17 AM

Thanks for that you learn something every day.

Back to top

#168 EunUCh

Lotsa Posts!

Members
2,769 posts

Location:not this planet
Car:japos
Joined: 23-November 06

Posted 17 August 2014 - 05:24 PM

Boring the crankpins made frokal difference,seems like according to the wear marks on the main journals that they suffer in the horizontal plane

vibration even though for all intents and purposes the counter balance weights and pins with rod big end weights seem to cancel each other out,my imagination says that this is wrong and that they need a heap more in the counter weight department,they are horrible little things but "IF" they didn't want to shake themselves

to pieces and some solution was found they would respond to a little blower and be "ok' for 240 bhp,maybe.

The problem is making shit to add some weight,not easy getting at those counter balance weights to bore holes and spread some weight around.

Back to top

#169 _oldjohnno_

Guests

Posted 17 August 2014 - 08:15 PM

I've said this already several times in this thread but here we go again: forget about "balance" and lighten the reciprocating bits. Too much mass in the piston and rod is the source of all your problems.

Back to top

#170 _STRAIGHTLINEMICK_

Guests

Posted 18 August 2014 - 10:40 PM

Just like Johno said dont worry about adding or removing weight off the crank it will get u nowhere, just have enough weight in the crank to balance it self .

Inline engines are balanced differently to V engines . In an inline engine the crank and everything that turns round with it is balanced to itself . You have two pistons up and two down at any given time so they cancel each other out if they are the same weights . The bearings will wear due to the crank being pulled ,pushed and bent in every direction by inertia of the pistons and rods going up and down and the fiiring strokes twisting effect on the crank .

The bigger the bang higher the rpm and the heavier the piston and rod combo is the worse the problem will be .(this also applies to 6cyls) . You dont want to reduce the bang for obvious reasons but u can reduce the reciprocating weight by lightening the rod and piston as much as possible . When these engines are used in speedway classes they use the stock 186/202 rod linished and shotpeened with arp bolts and a light weight piston as an easy and cheap way to lighten the reciproating mass .

Just make the biggest bang u can ,rev it as high as u dare and go out and have fun with it .

Mick

Edited by STRAIGHTLINEMICK, 18 August 2014 - 10:43 PM.

Back to top

#171 warrenm

Forum Fixture

Members
2,116 posts

Location:Central West NSW
Car:1972 LJ Torana
Joined: 08-November 05

View Garage

Posted 18 August 2014 - 11:51 PM

I think oldjohnno is trying to tell you something.

Back to top

#172 _oldjohnno_

Guests

Posted 19 August 2014 - 08:22 AM

When these engines are used in speedway classes they use the stock 186/202 rod linished and shotpeened with arp bolts and a light weight piston as an easy and cheap way to lighten the reciproating mass .

How many rpms are these blokes doing Mick?

Back to top

#173 EunUCh

Lotsa Posts!

Members
2,769 posts

Location:not this planet
Car:japos
Joined: 23-November 06

Posted 19 August 2014 - 04:26 PM

I get the bit about the way the pairs cancel each other out,and i get that making things lighter in the rod/piston area will help and that more pressure

equals more forces applied to everything which will result more power and wear,the bit i don't get is that the wear pattern on the crank that came from

a previous build had the bulk of the problem of wear on the main journals(and bearings) when crank was at 90deg atdc when the big ends and weights

were horizontal.

The wear was more or less 50% of the main journals and was worst on and consistent with being on the big end/pin 'side' on all

of them,this gave me the impression that 2&3 pins were going in opposite directions to 1&4 pins with more force than the weight could counter when they were at "horizontalish" causing the crank to bend hence the need for more or less weight in that area.The wear on the crank and bearings otherwise was "normal".

Will be easy enough to get some red rods but getting a 3.56 or better light piston with correct pin height and pin bore might be a bit different,not only that i don't

think gaskets are available anymore and full groove mains will probably will be out of the question as well.

Back to top

#174 _STRAIGHTLINEMICK_

Guests

Posted 19 August 2014 - 05:20 PM

How many rpms are these blokes doing Mick?

Not sure Johnno

Back to top

#175 _STRAIGHTLINEMICK_

Guests

Posted 19 August 2014 - 05:29 PM

Will be easy enough to get some red rods but getting a 3.56 or better light piston with correct pin height and pin bore might be a bit different,not only that i don't

think gaskets are available anymore and full groove mains will probably will be out of the question as well.

You can lighten the current piston by milling under the crown ,removing any unecessary metal and milling slots in the skirts or check yr wall thickness and bore to 186 std size and do the same.

Edited by STRAIGHTLINEMICK, 19 August 2014 - 05:30 PM.