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4 hours ago, Buz said:

I have a 2.4 frontera engine 👍.  Going to rebore it , new pistons and rods and the 16v top end . Simples 😂

The only part I am unsure of is the crank. Obviously with forged pistons and rods it can rev higher but I don’t know if the crank needs to be changed / uprated 

There was a guy in Sweden iirc selling a forged crank, it was very cheap like €10k 🤯
what about the Diesel crank?
 

Personally as your not going to turbo, a good balanced bottom end (matched rod weights etc) and Nitriding would be my choice

Edited by Jessopia74
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9 hours ago, 611 said:

What pistons are you going to go with?

I haven’t really done much research into pistons and rods , cams etc. I’ve read articles with lots  of manufacturers recommended.  With regards to pistons , wossner and omega seem popular choices

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9 hours ago, Jessopia74 said:

There was a guy in Sweden iirc selling a forged crank, it was very cheap like €10k 🤯
what about the Diesel crank?
 

Personally as your not going to turbo, a good balanced bottom end (matched rod weights etc) and Nitriding would be my choice

As long as the standard crank is capable of revving to 6000rpm safely then I think that’s realistically where I’m at. I’m not building a race car. More of a real world fantasy . I could strip the bottom end and find that the bores are perfect and don’t need touching but at 100k I doubt it so if I have to rebore it then I have to get new pistons , so I might as well spend a bit more on decent forged pistons and then maybe rods too but I also have to keep the budget real world too and not fantasy. I know the 16v cih is a more expensive route but i feel it keeps the heart of the car the same 

On 29/08/2020 at 21:49, 611 said:

If your going to that much effort on the engine you have to go throttle bodies and Omex 600 🙂

 

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Maybe these are the answer 

55C0460B-4746-4732-8324-2304F585294E.jpeg

8BFF1DB7-9CCD-4AD5-8C90-5F4056E6F16F.jpeg

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6 hours ago, Buz said:

As long as the standard crank is capable of revving to 6000rpm safely then I think that’s realistically where I’m at. I’m not building a race car. More of a real world fantasy . I could strip the bottom end and find that the bores are perfect and don’t need touching but at 100k I doubt it so if I have to rebore it then I have to get new pistons , so I might as well spend a bit more on decent forged pistons and then maybe rods too but I also have to keep the budget real world too and not fantasy. I know the 16v cih is a more expensive route but i feel it keeps the heart of the car the same 

Maybe these are the answer 

 

 

As I said, your key here is not what we perceive as (Tensile) strength of the crank as such, but the twisting action at higher rpm. This lack of ductile strength is what will kill a crank n/a engine. 

Absolute minimum is balance of bottom end, as your rods/pistons will no longer be matched to the counter weights. Lowering the rotational mass is a good thing, but making sure it's all static/dynamically balanced will really help you here.

a lot you can do yourself anyway, matching piston weight to rod weight, so that they are all equal. Or the best is to match all rods so they are exactly the same on big ends when supported at little end, then match with pistons.

Then send with Flywheel, pulley and crank to all be balanced. If you build the top end properly, you can be looking at a bottomless end that you can push the red line to 7.5K 😎 

 

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13 hours ago, Buz said:

As long as the standard crank is capable of revving to 6000rpm safely then I think that’s realistically where I’m at. I’m not building a race car. More of a real world fantasy . I could strip the bottom end and find that the bores are perfect and don’t need touching but at 100k I doubt it so if I have to rebore it then I have to get new pistons , so I might as well spend a bit more on decent forged pistons and then maybe rods too but I also have to keep the budget real world too and not fantasy. I know the 16v cih is a more expensive route but i feel it keeps the heart of the car the same 

Maybe these are the answer 

55C0460B-4746-4732-8324-2304F585294E.jpeg

8BFF1DB7-9CCD-4AD5-8C90-5F4056E6F16F.jpeg

They look interesting. What sort of cost for those??

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  • 4 months later...

Hi Buz,

im just catching up on this thread....not had a look in for a while

On 06/09/2020 at 07:56, Buz said:

I could strip the bottom end and find that the bores are perfect and don’t need touching but at 100k I doubt it so if I have to rebore it then I have to get new pistons

If it’s a frontera 2.4, I will put good money on the cylinder bores being oval and requiring a rebore or even hardened liners to sort it out.  How did you get on with things on the bottom end? 

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I’m embarrassed to say it’s still sat on the pallet in my shed . I’ve done nothing this year except source parts, which are still dotted around the country  awaiting collection . Southport, Oldham , Scunthorpe & Northampton to be precise. It’s a decent road trip 😂.  I do agree however that it is indeed extremely likely that the bores are oval. I will need new pistons anyway as it will be 16v and I can’t see the point of skimping on it whilst it’s all apart.  

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14 hours ago, Buz said:

I’m embarrassed to say it’s still sat on the pallet in my shed . I’ve done nothing this year except source parts, which are still dotted around the country  awaiting collection . Southport, Oldham , Scunthorpe & Northampton to be precise. It’s a decent road trip 😂.  I do agree however that it is indeed extremely likely that the bores are oval. I will need new pistons anyway as it will be 16v and I can’t see the point of skimping on it whilst it’s all apart.  

Herman is looking at pistons for his 400 at the moment, might be worth seeing what he comes up with as they seem quite hard to source.

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Yes I was looking for "400" forged pistons. Found a set at Risse (Omega ones) but had them yesterday on the phone. I contacted them cause today (the 26th) is the last day we are allowed to cross the German border to go after the set of pistons. They were very embarrased cause when opening the box they noticed one piston was missing. Till one of the guys said they lended the piston out to let it measured to copy them.  Hmm lets say I was not amused, luckily I phoned them before driving to them.

About the engine of Buzz, it all depends of what you are going to do with the car. The original "400" Mahle pistons have no "half moon" shaped notches. Only the ones with high compression. The plate designed top of a C24NE is even deeper then the "400" one:

f2YbZrJ.jpg

So technical the C24NE ones would fit in a "400"... Not sure what the valve lift of a shortened 24V head is? But if you are going to use the car on track days I would go for forged pistons. Had also an offer from "Flatlander", Wiseco forged pistons 855€ C.R 11/1 without taxes. 

Noticed Wiseco makes pistons for 2.4 CIH with rebuilded 24-16V head, will look for the info.

Grts, Herman

 

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2 hours ago, H-400 said:

Yes I was looking for "400" forged pistons. Found a set at Risse (Omega ones) but had them yesterday on the phone. I contacted them cause today (the 26th) is the last day we are allowed to cross the German border to go after the set of pistons. They were very embarrased cause when opening the box they noticed one piston was missing. Till one of the guys said they lended the piston out to let it measured to copy them.  Hmm lets say I was not amused, luckily I phoned them before driving to them.

About the engine of Buzz, it all depends of what you are going to do with the car. The original "400" Mahle pistons have no "half moon" shaped notches. Only the ones with high compression. The plate designed top of a C24NE is even deeper then the "400" one:

f2YbZrJ.jpg

So technical the C24NE ones would fit in a "400"... Not sure what the valve lift of a shortened 24V head is? But if you are going to use the car on track days I would go for forged pistons. Had also an offer from "Flatlander", Wiseco forged pistons 855€ C.R 11/1 without taxes. 

Noticed Wiseco makes pistons for 2.4 CIH with rebuilded 24-16V head, will look for the info.

Grts, Herman

 

Some guys on the Opel GT site seem to suggest that Chevy 305 pistons are very close and just need a skim on the top and the  pin bore enlarging?

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41 minutes ago, 611 said:

Some guys on the Opel GT site seem to suggest that Chevy 305 pistons are very close and just need a skim on the top and the  pin bore enlarging?

Yeah, I read that too. Cheap too. There are other options all depends if you are wanting to get the magic Rod Ratio.

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31 minutes ago, Jessopia74 said:

Yeah, I read that too. Cheap too. There are other options all depends if you are wanting to get the magic Rod Ratio.

All far too technical for me 🙂

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Standard 24v pistons do have cut outs for valves in the top.  Both the 3.0 and the 2.4 share the same bore but different strokes but I have no idea how the pistons compare in other physical dimensions. I have seen pistons available from varied suppliers and manufacturers including Wisecco , Omega and JE pistons and Risse, Westspeed etc.  With a range from 0.5 to 2.0mm oversize. My preference seems to be the omega ones but I need to contact them for further info. Obviously at this time it’s ideal then to match or make changes to con rod lengths.  I’m waiting to find another head as I want to convert 2 at the same time , so I’m reluctant to start stripping down yet as I don’t want to lose parts.  

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45 minutes ago, Buz said:

Standard 24v pistons do have cut outs for valves in the top.  Both the 3.0 and the 2.4 share the same bore but different strokes but I have no idea how the pistons compare in other physical dimensions. I have seen pistons available from varied suppliers and manufacturers including Wisecco , Omega and JE pistons and Risse, Westspeed etc.  With a range from 0.5 to 2.0mm oversize. My preference seems to be the omega ones but I need to contact them for further info. Obviously at this time it’s ideal then to match or make changes to con rod lengths.  I’m waiting to find another head as I want to convert 2 at the same time , so I’m reluctant to start stripping down yet as I don’t want to lose parts.  

What you doing about camshafts?

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There are a few options. You can get custom custom  or “off the shelf” camshafts relatively easily. As you know the 16V Facebook group is quite good for info and resources but everything is expensive 🤣  As for profile , I was kind of thinking  fast road territory ish probably 🤪

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It’s very excessive. They are taking advantage of us poor deluded fools. It does seem maybe to be an expensive troublesome route but at least it’s only contained within the engine itself and not into the chassis.

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About 30 years ago had a 1976 Z1000 got cams reworked to stage 2 , head reworked ect

Before the rework at 5;000 RPM doing 70 MPH ,After the rework at 5,000 RPM doing 90 MPH 

If you can cams reworked it will be a cheaper option 

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46 minutes ago, Buz said:

It’s very excessive. They are taking advantage of us poor deluded fools. It does seem maybe to be an expensive troublesome route but at least it’s only contained within the engine itself and not into the chassis.

Indeed mate. It's a long term aspiration for me, but will collect parts for my head if they come it at reasonable costs. I think £600 is very reasonable for a pair imo. I will be reluctant to pay over that.

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