STRAIGHT SWAP FLAT TOPS

[Limey]

Hi all,

3 things I need your help with if you know,

1) For a vizard mod - is there a straight swap flat top piston out there to replace my dished units?
2) What part numbers for the Datsun diesel /petrol valves and guides (Jerry??) My engineer wants one of ach for appraisal
3) What Schrick springs part number for a) standard tappet ratio and b) for 1.6-1 roller rockers. max 6000rpm

Yours in hope (and a bit lazy, not wanting to re-invent the wheel and all that...) These are for my 1961 Judson blower Alpine and 1959 racing boat Alpine

Thanks in hope,

Oliver

 

[alpine_64]

Oliver what bore have you got on the motor? Std or over sized? You want pistons for Rootes motor...or replacement pistons..

JP had flattops for Rootes motors...but I don't consider them high performance...just basic ..

There are NOS Rootes specific pistons on eBay UK from hepolite and AE etc..

Hi all,

3 things I need your help with if you know,

1) For a vizard mod - is there a straight swap flat top piston out there to replace my dished units?
2) What part numbers for the Datsun diesel /petrol valves and guides (Jerry??) My engineer wants one of ach for appraisal
3) What Schrick springs part number for a) standard tappet ratio and b) for 1.6-1 roller rockers. max 6000rpm

Yours in hope (and a bit lazy, not wanting to re-invent the wheel and all that...) These are for my 1961 Judson blower Alpine and 1959 racing boat Alpine

Thanks in hope,

Oliver

 

[puff4]

I used dish tops on my Vizard mod engine because my head had been previously shaved considerably and bore enlarged by the original owner. If yours has been shaved, and you’re bore enlarged, and you’re looking to build an engine with near-stock compression ratio (particularly if you’re gonna use a blower), you may not want flat tops. Have you done the math? And what’s your end goal?

 

[jumpinjan]

I bought mine years ago from Victoria British. I think they were made by "King", if I remember?
Jan

 

[Five Reviver]

Oliver, yes, JP certainly do them. You can buy them direct (Nornda Automotive) or through autosurplus.com.au. Photos on Messenger
David

 

[Limey]

I used dish tops on my Vizard mod engine because my head had been previously shaved considerably and bore enlarged by the original owner. If yours has been shaved, and you’re bore enlarged, and you’re looking to build an engine with near-stock compression ratio (particularly if you’re gonna use a blower), you may not want flat tops. Have you done the math? And what’s your end goal?

Hi and thanks - Flat tops are for a Vizard1600 not the blower Ihave a previously rebuilt bottom half so justwant the opton to flat top it if the maths indicate that requirment. Cheers, Oliver

 

[Limey]

Oliver what bore have you got on the motor? Std or over sized? You want pistons for Rootes motor...or replacement pistons..

JP had flattops for Rootes motors...but I don't consider them high performance...just basic ..

There are NOS Rootes specific pistons on eBay UK from hepolite and AE etc..

Thanks Michael - Just checking option if i need to adjust fto get the CR up to 10 approx

 

[Eleven]

Late checking in. PO on my car put in flat top pistons with a stock head. Net effect is you have to run premium gas to control knock and you get zero performance improvement. In short, unless to you build to get a real benefit, there is little point to them for street use. My humble opinion

 

[alpine_64]

Late checking in. PO on my car put in flat top pistons with a stock head. Net effect is you have to run premium gas to control knock and you get zero performance improvement. In short, unless to you build to get a real benefit, there is little point to them for street use. My humble opinion

I'll have to disagree... While doing further mods to the motor would yield more from the change .. a bump in compression will bump up power .... And yes you will have to run higher octane fuel ( and I would guess your head had a least a light skim in its life.. so would likely be a little higher yet.

If you had the flat tops and ran higher octane fuel you could have also advanced the timing a little to get more out of it

 

[Eleven]

I'll have to disagree... While doing further mods to the motor would yield more from the change .. a bump in compression will bump up power .... And yes you will have to run higher octane fuel ( and I would guess your head had a least a light skim in its life.. so would likely be a little higher yet.

If you had the flat tops and ran higher octane fuel you could have also advanced the timing a little to get more out of it

True. Poorly worded on my part. My view is that the piston shape comes at the end to make sure they do what you want. On my car the PO just slapped them in and apparently expected some big gain. Ah no.