Turbo on 250 crossflow

[Fknclevo 3]

thinking about turbocharging my carby 250 crossflow out of xf (alloyhead) but have almost no knowledge of them, I’m planning to build a built clevo or turbo crossflow both have pros and cons for my purposes wondering if I’d make similar power for similar cash on each engine.

what is weakest parts and are there fixes or just buying stronger parts,  

are aftermarket parts still being made 

are there turbo kits available 

what sort of power am I looking to make reliably don’t want much more then around 400-450 at crank, want to stay carby. probably other questions I’m forgetting to ask but we will cross that bridge later 

 

[slydog 7,873]

Seen a guy from Wellington make over 450whp on a stock blow thru xflow with a ebay turbo. 

 

Mine made 460fwhp NA and would beat alot of 400kw cars at the track. So hp number means nothing if set up is not on point. 

 

But lets assume you turbo a xflow with stock flowing head with a xr6 turbo. Prob 500hp is a safe number on good tune and fuel. 

[Fknclevo 3]

1 minute ago, slydog said:

Seen a guy from Wellington make over 450whp on a stock blow thru xflow with a ebay turbo. 

 

Mine made 460fwhp NA and would beat alot of 400kw cars at the track. So hp number means nothing if set up is not on point. 

 

But lets assume you turbo a xflow with stock flowing head with a xr6 turbo. Prob 500hp is a safe number on good tune and fuel. 

Don’t know much about them how are their bottom ends and what would I need to do to make it reliable and is it worth spending that money or should I just build a cleveland

[XCeed 205]

Hi Fknclevo,

 

If you decide to go with the Crossflow, read up on Slydog's XF Ute build thread in Projects/Extreme Builds section.

 

This is my favourite post of his in the thread:

 

 

[Fknclevo 3]

55 minutes ago, XCeed said:

Hi Fknclevo,

 

If you decide to go with the Crossflow, read up on Slydog's XF Ute build thread in Projects/Extreme Builds section.

 

This is my favourite post of his in the thread:

 

 

Which build would I end up spending more money on to get around 400-450 at the crank reliably, turbo Crossy or na clevo

[XCeed 205]

$$$? I've got no idea.

 

Pavtek website, $18,550 for a 393 Cleveland long motor 485HP off the shelf.

 

Turbo build, how much of the fabrication work can you do yourself? My understanding is that there are no Crossflow kits available off the shelf. Custom turbo exhaust manifold, custom everything! You'll have to pay megabucks to get everything fabricated, maybe block machined to suit an EF Falcon crankshaft, conrods, pistons, dyno tuning, etc, etc.

 

Everything I've read about Crossflows on this forum is that Crossys are not not designed for huge power, but you can build them into a torque monster with boost, keeping revs down below 5500.

 

Isn't there an old rule of thumb, if you want 1HP or more per cubic inch of displacement, you have to start spending lots of money. I suspect it would be cheaper to buy a built 351 Cleveland off the shelf to achieve 400HP than build a blown Crossflow.

[slydog 7,873]

Well... my engine could be copied for nearly half of a $18,000 clevo. However every engine needs fuel system, ignition, exhaust and so on. 

 

A turbo xflow is cheaper than a na clevo. Remember a clevo still needs cyl heads to work, ignition exhaust manifold carburettor and so on. But its all the same regardless of engine really.

 

A xflow bottom end needs a quality damper and flexplate. Pushrods, convert to a solid lifter cam and cyl head porting. Porting is free hp that all but doubles with boost.

 

But big 1 is how much can you do yourself if your asking money money money before you start. Money usually kills a build before it starts in most cases. I however just did it over many years...and still going. 

 

First race out from turbo build raced a NA clevo XA. Beat it running a 10.7 to his 11.1.

Next meeting first race was against a clevo xy. We both went 10.3 129 but I won by a better reaction time. But my car costs way less than both of theres and beat em. However its still more than most want to spend which is the part that makes or breaks the car. 

[Fknclevo 3]

18 minutes ago, slydog said:

Well... my engine could be copied for nearly half of a $18,000 clevo. However every engine needs fuel system, ignition, exhaust and so on. 

 

A turbo xflow is cheaper than a na clevo. Remember a clevo still needs cyl heads to work, ignition exhaust manifold carburettor and so on. But its all the same regardless of engine really.

 

A xflow bottom end needs a quality damper and flexplate. Pushrods, convert to a solid lifter cam and cyl head porting. Porting is free hp that all but doubles with boost.

 

But big 1 is how much can you do yourself if your asking money money money before you start. Money usually kills a build before it starts in most cases. I however just did it over many years...and still going. 

 

First race out from turbo build raced a NA clevo XA. Beat it running a 10.7 to his 11.1.

Next meeting first race was against a clevo xy. We both went 10.3 129 but I won by a better reaction time. But my car costs way less than both of theres and beat em. However its still more than most want to spend which is the part that makes or breaks the car. 

Won’t be doing to much drag racing more of a street car, have a top loader, stock 302 Cleveland and a couple crossflows I’m either gonna piece together a beefy top end on the Cleveland go a 6inch rod 351 and try to stay with the standard 2v cc and port the shit out of them which will not run me to 18k🫣 have a fuel system for a carby that will support upto 700hp

just very not knowledgeable on the crossys and how much it would run me but cheers for the info almost all the work will be done at home unless I go Crossy and it needs dyno tune etc 

[slydog 7,873]

So if you know a clevo you know xflows. Same shitty valve train in both. Both have same issues except cyl heads flow differently but both crap.

 

And as expected your not going to build 1 anyway lol. 

[Fknclevo 3]

8 hours ago, slydog said:

So if you know a clevo you know xflows. Same shitty valve train in both. Both have same issues except cyl heads flow differently but both crap.

 

And as expected your not going to build 1 anyway lol. 

Wdum im not going to build one anyway?