11 replies to this topic

[mvahora]

Hi guys,

 

Have a few Qs 

 

I have a modified eng 1275 + 40, piper 285 cam, 45D dizzy with lumenition electronic ignition, hilift roller rockers, main bearings -020, conrod bearings -020, camshaft bearings, cam lifters, twin hs2 carbs and many other smaller items. It has also been tapped and drilled from 9 stud to 11 stud.

 

Receipts say a stage 1 modified head by a custom engine builder. I however actually think this may be a stage 2 head as the receipt shows upgrade of 1.401" / 35.6mm stainless steel inlet race valves as well as upgraded stainless steel race exhaust valves, set double valve springs and inner valve spring seats, 

 

Q1. Would i be correct to assume it also has steel valve guides and unleaded valve guides as a result of the above upgrades?  

 

Q2. Would i be correct in assuming this builders stage 1 head would perhaps be a stage 2 for example that minisport in the uk supply as a result of the upgraded parts?

 

Q3. what is the stage factor dictated by? is it the chamber size or how much the head has been ported?

 

 

Thanks

Edited by mvahora, 21 May 2020 - 05:51 PM.

[nicklouse]

1 nope

2 nope

3 whatever some one thinks. There is no standard. 
 

never assume anything. Open it up and look.

 

steel valve guide is basic road use. You don’t get unleaded guides you mean seats.

 

bigger valves on their own mean little. Has it had any porting done? Has the combustion chamber been modified? Does the combustion chamber the right size to give the CR for the piper cam?

 

so which rockers does it have it will not have a mix.

 

to me it does sound more like a collection of parts rather than a build.

 

as the Hs2 card will be a real limiting factor if the head has had some work done. Even if it has not had much done they will still be a big limiting factor.

[Turbo Phil]

No such thing as steel valve guides. They will either be iron or some form of bronze. If it has stainless race valves fitted they will be bronze.
The “stage” thing is almost meaningless as it differs from company to company. The 285 cam is quite “sporty” and as such the head will need to be quite well modified to get anywhere near the best from that type of cam.

Phil.

[mvahora]

1 nope

2 nope

3 whatever some one thinks. There is no standard. 
 

never assume anything. Open it up and look.

 

steel valve guide is basic road use. You don’t get unleaded guides you mean seats.

 

bigger valves on their own mean little. Has it had any porting done? Has the combustion chamber been modified? Does the combustion chamber the right size to give the CR for the piper cam?

 

so which rockers does it have it will not have a mix.

 

to me it does sound more like a collection of parts rather than a build.

 

as the Hs2 card will be a real limiting factor if the head has had some work done. Even if it has not had much done they will still be a big limiting factor.

 

No such thing as steel valve guides. They will either be iron or some form of bronze. If it has stainless race valves fitted they will be bronze.
The “stage” thing is almost meaningless as it differs from company to company. The 285 cam is quite “sporty” and as such the head will need to be quite well modified to get anywhere near the best from that type of cam.

Phil.

 

thanks for the reply, i pulled this motor out of another mini and it was going well, there has been work done to it. I would like to determine how much work has actually been done to the head so that i can make improvements and get it setup right.. Is there any way to figure this out without opening it up?

 

ive been told it has had some light porting and machining done to it. but dont know precisely how much.

 

i stated 1.3 and 1.5 as im not sure which has been installed, I do know they are hi lift roller rockers and that they are gold in colour when looking at them from the rocker cover. 

 

you would think that with this amount of work done and the spec listed above it would be a misfit to install a so called "stage 1" head? 

 

ive uploaded pics below showing the works done. would love to know ur guys thoughts. 

Edited by mvahora, 22 May 2020 - 11:22 AM.

[mvahora]

1 - 5 attachments

Edited by mvahora, 03 June 2020 - 12:05 AM.

[mvahora]

attachements

Edited by mvahora, 03 June 2020 - 12:05 AM.

[mvahora]

Does anyone have any information / advise on the above pics? Thanks

Edited by mvahora, 22 May 2020 - 10:51 AM.

[nicklouse]

You will have to find Lynne Rogers and ask.

Edited by nicklouse, 22 May 2020 - 11:18 AM.

[gazza82]

You will have to find Lynne Rogers and ask.

Might not be so easy ..

 

 LynnRogersAuto.jpg   31.25K   0 downloads

 

https://www.harrisperformancenz.co.nz/

 

[gazza82]

Is there any way to figure this out without opening it up?

 

ive been told it has had some light porting and machining done to it. but dont know precisely how much.

 

 

1. Nope

2. You'd have to compare it to a standard head ..

 

[mvahora]

You will have to find Lynne Rogers and ask.

 

Yes will do, Gazza above managed to find them will get in touch with them.

Edited by mvahora, 22 May 2020 - 12:17 PM.

[nicklouse]

Well Harris are well known for excellent work. They may have info on the head. Check for any stamps that might help ID it.