Dot Head on a 1052?

[spiderpig]

Will a Dot head go on gsxf barrels on a 1052 bottom? 

It's not mentioned in frankensteins guide. 

Have a load of motor parts knocking about and thinking about building a frankenmotor 

[wraith]

Are the 1052 bottom a shorter stroke than the 1127? 

Think @clivegto has a dot head on a 1052 motor ?

 

[Devilman]

1052, 1127 and 1157 barrels are all interchangeable, Dot head will fit all of them too, obviously need to use the correct chain / sprockets to suit the crank.

However, 1052 has 1mm shorter stroke, so barrels are shorter which conversely means if you were to put 1127 barrels on a 1052 crank, you'll lose compression and open up the squish band, robbing you of performance.

I guess you could get the barrels "decked" to shave 1mm off them, but they might be difficult to sell on if you ever wanted to, as a set of 1127 barrels that are only 58mm stroke might not find many buyers.

*Edit*

Not sure how thick a standard base gasket is and whether or not if you had really clean and flat mating surfaces you may be able to do away with it in favor of "form in place gasket" (RTV basically) to regain a bit? 

Edited October 26, 2022 by Devilman

[clivegto]

35 minutes ago, wraith said:

 

Think @clivegto has a dot head on a 1052 motor ?

 

Yes, 1052 motor with gsxr750j/k ported (dot) head and cams. Best way to describe the motor is it goes like a screaming banchee 

[spiderpig]

Cheers gents. 

Plan is 1052 bottom, busa pistons and rods, 1127f barrels, ported and skimmed dot head with reground cams. 

I know the head was skimmed that much that it needed a base spacer to lower comp when on a 748 race motor. 

Not exactly straight forward, but fuck it, why not 

I'm thinking between the skimmed head and busa rods ill more likely have reduce the comp. Will have to wait and see unless one of the brains on here can fill in the gaps for me 

[Devilman]

1 hour ago, spiderpig said:

Cheers gents. 

Plan is 1052 bottom, busa pistons and rods, 1127f barrels, ported and skimmed dot head with reground cams. 

I know the head was skimmed that much that it needed a base spacer to lower comp when on a 748 race motor. 

Not exactly straight forward, but fuck it, why not 

I'm thinking between the skimmed head and busa rods ill more likely have reduce the comp. Will have to wait and see unless one of the brains on here can fill in the gaps for me 

From memory Busa rods are 2.5mm longer than GSXR rods, so even with the 1mm shorter stroke of the 1052 crank, you'll need some kind of spacer to prevent piston-to-head contact 

You should end up with around 1195/1196cc but as to compression ratio, that will depend greatly on how much the combustion chamber volume has been reduced by the skimming, and some math with the swept volume of the cylinder, etc.. etc..

There may be calculators out there now that you can punch the numbers into (bore, stroke, chamber capacity, squish band, valve-pocket capacity on the piston crown etc..) but I don't know of any personally.

[davecara]

8 hours ago, Devilman said:

From memory Busa rods are 2.5mm longer than GSXR rods, so even with the 1mm shorter stroke of the 1052 crank, you'll need some kind of spacer to prevent piston-to-head contact 

You should end up with around 1195/1196cc but as to compression ratio, that will depend greatly on how much the combustion chamber volume has been reduced by the skimming, and some math with the swept volume of the cylinder, etc.. etc..

There may be calculators out there now that you can punch the numbers into (bore, stroke, chamber capacity, squish band, valve-pocket capacity on the piston crown etc..) but I don't know of any personally.

https://www.omnicalculator.com/everyday-life/compression-ratio

 

[Devilman]

3 hours ago, davecara said:

https://www.omnicalculator.com/everyday-life/compression-ratio

 

Nice, that's an awesome calculator, should prove very useful to some folks 


*Edit*   Just to say... I wasn't really sure how to make the mods aware of my following suggestion without "spamming" the thread or creating another one just to ask it, so I have "reported" (not in negative terms) your post and asked the mods to create a "Useful Resources / Links" thread that could contain such very useful resources such as this and keep it pinned to the top of the board. 

I Pray it does not cause any issues or trouble for you or the mods, It just seemed like a prudent way to bring their attention to something very useful 

Edited October 27, 2022 by Devilman

[Blubber]

3 hours ago, Devilman said:

Nice, that's an awesome calculator, should prove very useful to some folks 


*Edit*   Just to say... I wasn't really sure how to make the mods aware of my following suggestion without "spamming" the thread or creating another one just to ask it, so I have "reported" (not in negative terms) your post and asked the mods to create a "Useful Resources / Links" thread that could contain such very useful resources such as this and keep it pinned to the top of the board. 

I Pray it does not cause any issues or trouble for you or the mods, It just seemed like a prudent way to bring their attention to something very useful 

Most just ask or might even use the search option. Very few look at the pinned topics.  

[spiderpig]

On 10/26/2022 at 11:42 PM, Devilman said:

From memory Busa rods are 2.5mm longer than GSXR rods, so even with the 1mm shorter stroke of the 1052 crank, you'll need some kind of spacer to prevent piston-to-head contact 

You should end up with around 1195/1196cc but as to compression ratio, that will depend greatly on how much the combustion chamber volume has been reduced by the skimming, and some math with the swept volume of the cylinder, etc.. etc..

There may be calculators out there now that you can punch the numbers into (bore, stroke, chamber capacity, squish band, valve-pocket capacity on the piston crown etc..) but I don't know of any personally.

Yep rods are longer, with the shorter stroke and taller block it shouldn't be too far off. 

Will be measuring the chamber volume and doing the maths when I get everything together. 

 

The other issue is the 1052 oil return tubes are seized in the cases so have to sort that out first 

[Metralla]

I have a 1052 and I wonder If it is better to gas flow a DOT head or the original. My issue is that I want to fit original BST34s with the original airbox and there is not enough info about it. Any clues?

[DAZ]

13 hours ago, Metralla said:

I have a 1052 and I wonder If it is better to gas flow a DOT head or the original. My issue is that I want to fit original BST34s with the original airbox and there is not enough info about it. Any clues?

Dot head has "semi down draught"  intake ports  and raise the angle of the carbs so you couldn't use your air box they were used on 750 short stroke motors that were in j/k slingshots 

[Gixer1460]

On 10/26/2022 at 11:42 PM, Devilman said:

You should end up with around 1195/1196cc 

Eh ? ? ? Using a 1052 crank and without changing the bore - you'll end up with . . . . . . 1052cc ! You could put 1m long rods on the crank and you'd still only get 1052cc!

You can ONLY change capacity by varying either the bore dimension and / or the stroke length !

[Captain Chaos]

10 minutes ago, Gixer1460 said:

Eh ? ? ? Using a 1052 crank and without changing the bore - you'll end up with . . . . . . 1052cc ! You could put 1m long rods on the crank and you'd still only get 1052cc!

You can ONLY change capacity by varying either the bore dimension and / or the stroke length !

you're right but Devilman is talking about Busa pistons with 1052 crank.

Try reading a complete post before commenting about it.

[Gixer1460]

1 minute ago, Captain Chaos said:

you're right but Devilman is talking about Busa pistons with 1052 crank.

Try reading a complete post before commenting about it.

Appalogees - wasn't clear! 

Oh - and like i'm the first to commit that particular faux pas ! ! ! 

[Sandman]

On 10/26/2022 at 10:33 PM, Devilman said:

1052, 1127 and 1157 barrels are all interchangeable, Dot head will fit all of them too, obviously need to use the correct chain / sprockets to suit the crank.

However, 1052 has 1mm shorter stroke, so barrels are shorter which conversely means if you were to put 1127 barrels on a 1052 crank, you'll lose compression and open up the squish band, robbing you of performance.

I guess you could get the barrels "decked" to shave 1mm off them, but they might be difficult to sell on if you ever wanted to, as a set of 1127 barrels that are only 58mm stroke might not find many buyers.

*Edit*

Not sure how thick a standard base gasket is and whether or not if you had really clean and flat mating surfaces you may be able to do away with it in favor of "form in place gasket" (RTV basically) to regain a bit? 

This is not correct. All barrels for 1052 cc 1127 cc and 1157 cc have the same heigth. The length of the conrods for 1052 cc are 117.4 mm, and 1127 cc and 1157 cc are 117.0 mm. Therefore, the squish height for 1052 cc is 0.1 mm larger compared to the 1127 cc and 1157 cc engines (theoretlically) .

The DOT head for GSXR 750 -88/89 are equal to the GSX750F. The difference is the camshafts. GSX750F has shorter duration and lower lift compared to GSXR 750.

The DOT head comes with higher valve spring stiffness compared to the 1052 cc 1127 cc and 1157 cc engines. The rev limiter is higher for GSXR 750 -88/89 and GSX750F compared to 1052 cc, 1127 cc and 1157 cc engines. The valve stiffness for the DOT head is equal to the Yoshimura valve spring kit for ST-2 cams. The valve springs for the DOT head needs to be shimmed to get the correct seat pressure.

Edited January 22, 2023 by Sandman

[DAZ]

Thank you for the information,especially about the valve springs 

[george 1100]

10 hours ago, Sandman said:

This is not correct. All barrels for 1052 cc 1127 cc and 1157 cc have the same heigth. The length of the conrods for 1052 cc are 117.4 mm, and 1127 cc and 1157 cc are 117.0 mm. Therefore, the squish height for 1052 cc is 0.1 mm larger compared to the 1127 cc and 1157 cc engines (theoretlically) .

The DOT head for GSXR 750 -88/89 are equal to the GSX750F. The difference is the camshafts. GSX750F has shorter duration and lower lift compared to GSXR 750.

The DOT head comes with higher valve spring stiffness compared to the 1052 cc 1127 cc and 1157 cc engines. The rev limiter is higher for GSXR 750 -88/89 and GSX750F compared to 1052 cc, 1127 cc and 1157 cc engines. The valve stiffness for the DOT head is equal to the Yoshimura valve spring kit for ST-2 cams. The valve springs for the DOT head needs to be shimmed to get the correct seat pressure.

Correct but the 750 spring cannot be used with the ST2 10mm lift cams as they will coil bind

[Duckndive]

On 1/21/2023 at 10:03 PM, Metralla said:

I have a 1052 and I wonder If it is better to gas flow a DOT head or the original. My issue is that I want to fit original BST34s with the original airbox and there is not enough info about it. Any clues?

I would Port the original head and sell the Dot one