Possible car rebuild - crossflow engine

[6carjon]

Not a cross flow expert but I wouldn't have this in a road car as it's really trackday or race orientated. Anything with a lumpy idle will be very annoying in regular road use and low on torque unless you get it to 4000rpm ish at a guess which is exciting at first but short lived excitement in my experience. Now a fully qualified old git.

[Yanto]

32 minutes ago, 6carjon said:

Not a cross flow expert but I wouldn't have this in a road car as it's really trackday or race orientated. Anything with a lumpy idle will be very annoying in regular road use and low on torque unless you get it to 4000rpm ish at a guess which is exciting at first but short lived excitement in my experience. Now a fully qualified old git.

Yes, i fully agree with you, not something I would want.

[Jim G]

30 minutes ago, Yanto said:

Yes, i fully agree with you, not something I would want.

You could possibly change the cam easy enough and sell the a6?

[B.RAD]

Quote "CR will be about 10:1."

sends shivers down my spine. If he's a decent engine builder, he will have measured the CR accurately and tell you exactly what it is. The headwork can massively impact the CR on these engines making the head gasket thickness, block skim depth etc absolutely critical. Did he confirm if the pistons are forged or STD? If not forged, don't bother.

I wouldn't worry too much about lumpy idle, on a crossflow it's manageable and the kick at 4000rpm is worth putting up with it for! Needs a proper gearbox to manage it though, a std type 9 doesn't suit a racey cam - have experienced this and it ruins the drive. A close ratio box with a race cam is great, or a 234 cam with a std box is also great. Just don't mix the two!

[Yanto]

I didn't ask about pistons, but I did look them up as you'd mentioned them, and you were corrected, just std replacement ones, did make me wonder if skimping on pistons for a higher CR and potentially higher revving engine if anything else internal is skimped on.

Could always buy it, change cam shaft, change pistons and check it all over, oh hang on, that would be stripping and rebuilding a stripped and rebuilt engine.

[Mighty Mart]

I'm no expert, having just jumped into westfield and xflow ownership in the last two years....

i love my crossflow by the way......

so talking about a std crossflow, or one possibly tweaked a bit, and talking about a proper power crossflow is chalk and cheese to be honest.....

nearly everyone that has a crossflow talks of power of 120 bhp plus.....this is a rarity in general, despite what people like to think they have? Rolling roads are notorious for power gains as well, as it sells the tuning or upgrades that have just been done....

i have receipts for my engine....a part rebuild of the original owners supplied engine, amounting to £2431 inc vat in 1996!

i would suggest that this was probably the most you could have paid for one at the time! for fast road use. It's not quite in its first flush of youth now, but feels very quick and was tested at 140 bhp last year, so still no slouch.

not too sure what the spec would cost now, but certainly wouldn't be cheaper. 

The only issue I can see with the linked engine would be the pistons, as everything else looks good. With carbs etc, it looks a good price, but rebuilding with decent pistons would add another four / five hundred in parts alone I'd reckon.

mart.

[B.RAD]

As above, forged pistons are around £4-500 - if you could get the engine for under £1500 and were willing to strip & rebuild, testing everything properly and installing forged pistons, I think you'd be ok.

Also check the exact specs of the cylinder head, a lot of the crossflow community refer to 'big valve' heads as an upgrade, they're just a 1600 GT head and the valves are only fractionally larger than std, they're not actually a worked head. A properly sorted head will have the ports ground out extensively, which also involves machining down the bronze guides, something few builders bother to do but makes a huge difference. If that has been done, and it has larger valves installed, it's probably worth £1000 on its own (cost to get a head and have an engineer install valves, hardened seats for unleaded and the machining/flow work).

I'd still be cagey about what you could end up with though, if the blocks been decked too far already or corners have been cut, you could easily find yourself putting another £1500 into it.

HTH!

[IanD]

Personally I think if the spec and parts are right as others have said then I think its about the right cost. Its got some nice buts on there.

But. there are a few things that don't sound quite right to me. 150bhp from a Cross flow is quite a lot and it would need some good head work and forged pistons to do this.

The comment of about 10:1 as BCF says is a bit worrying.

That exhaust looks pants. lol.  

Now the bit that I am not too sure about so happy to be proved wrong, but something worth checking. I didn't think those pistons were for use on a chambered head. Most Cross flows (especially 711 blocks) had a flat head and combustion chamber in the pistons as these seem to have so also having a chambered head doesn't sound right to me. Hopfully some one who has had this set up will be here in a min to tell me I am wrong.

I believe that type of head is now quite rare though so probably more valuable

Cheers

Ian

[Thrustyjust]

My pre-lit crossflow cost me a load more than 2 grand, more like double. It had offset roller rockers on the top ( Titan) . I had a cylinder head which cost nearly £800 alone and was pretty well developed. I had a lightweight steel flywheel, duplex adjustable timing pulley. It also had the main bearing caps replaced with steel ones and line bored. The pistons were 83.5mm Arias forged , which gave it a true 1699cc. It had a hp oil pump, jenvey alloy wet sump also Running a Newman special cam too. Power was a 'genuine' 145 bhp with reliability thrown in. The list of those parts would far outweigh the cost of 2 grand and was probably one of the reasons the current Mrs TJ , became the previous Mrs TJ . But here is the issue. For the money I spent, I could have had a brand new Zetec on the same carbs with more power and probably a few grand in the bank. Crossflows are lovely little engines, but to get more than 145 bhp is definately possible with an open wallet, but to get to 180bhp of untractable road engine, you can get the same bhp from a Zetec , standard engine, albeit a 2ltr.

[Jim G]

57 minutes ago, Thrustyjust said:

My pre-lit crossflow cost me a load more than 2 grand, more like double. It had offset roller rockers on the top ( Titan) . I had a cylinder head which cost nearly £800 alone and was pretty well developed. I had a lightweight steel flywheel, duplex adjustable timing pulley. It also had the main bearing caps replaced with steel ones and line bored. The pistons were 83.5mm Arias forged , which gave it a true 1699cc. It had a hp oil pump, jenvey alloy wet sump also Running a Newman special cam too. Power was a 'genuine' 145 bhp with reliability thrown in. The list of those parts would far outweigh the cost of 2 grand and was probably one of the reasons the current Mrs TJ , became the previous Mrs TJ . But here is the issue. For the money I spent, I could have had a brand new Zetec on the same carbs with more power and probably a few grand in the bank. Crossflows are lovely little engines, but to get more than 145 bhp is definately possible with an open wallet, but to get to 180bhp of untractable road engine, you can get the same bhp from a Zetec , standard engine, albeit a 2ltr.

It all depends on what you want from the car. A Zetec is an easy option, anyone could put one in and it will be boringly reliable, BUT for me, it just doesn't have that 'cool' factor. To me the X-Flow is an engine that makes me feel good just by lifting the bonnet.. I don't even have to start it  it has character that modern engines lack, and that smell... modern engines just don't smell like that.   But it comes at a price..

[B.RAD]

2 hours ago, IanD said:

Now the bit that I am not too sure about so happy to be proved wrong, but something worth checking. I didn't think those pistons were for use on a chambered head. Most Cross flows (especially 711 blocks) had a flat head and combustion chamber in the pistons as these seem to have so also having a chambered head doesn't sound right to me. Hopfully some one who has had this set up will be here in a min to tell me I am wrong.

Agree with you Ian, having just reread the ad, a chambered head (from a very early crossflow) is normally used with flat top forged pistons to create a high CR engine - you would not use this with 1300 pistons as they have a chamber in the top. 

I'm torn between feeling like there's too many question marks to make this a risk free purchase, alongside also seeing the potential from the spec list. I think I come back to it being a good buy at £1000-£1500 with the plan to budget £1000 to take it apart and answer those questions for yourself. 

Have you got a car to put it in yet??

[Yanto]

I have seen a chassis, and I would buy it now if only I could source the bits to make it a nice car reasonably, unfortunately for me the budget is small and finite, despite the desire to say "to hell with it and spend" which is my usual default position.

Engine wise i don't want a racing spec, i would like an easy going set up with mild performance.

Ian

[Jim G]

2 hours ago, Yanto said:

I have seen a chassis, and I would buy it now if only I could source the bits to make it a nice car reasonably, unfortunately for me the budget is small and finite, despite the desire to say "to hell with it and spend" which is my usual default position.

Engine wise i don't want a racing spec, i would like an easy going set up with mild performance.

Ian

If the chassis is right for you and the right price, buy it and just wait. An engine will turn up and in the mean time you can be doing stuff to the chassis. That would be my way of doing it.  Good luck 

[DamperMan]

Over the years I have driven a caterham with race spec k series, 6 speed box and it was very quick but I didn't want it.  within a few weeks I drove a nice sorted older caterham with a 1700 mighty crossflow which had loads of work on it and well sorted. I don't remember the exact engine spec.  The sound was so invocative. The power delivery was great and I loved the way it came on cam.   It was that car which made me want a 7... and hence now I have the Westfield.   The zetec i have is value power for money but no sole,  I feel no passion fire the engine just the way it makes the car go. The cross flow has a sole. 

[Jim G]

4 minutes ago, DamperMan said:

Over the years I have driven a caterham with race spec k series, 6 speed box and it was very quick but I didn't want it.  within a few weeks I drove a nice sorted older caterham with a 1700 mighty crossflow which had loads of work on it and well sorted. I don't remember the exact engine spec.  The sound was so invocative. The power delivery was great and I loved the way it came on cam.   It was that car which made me want a 7... and hence now I have the Westfield.   The zetec i have is value power for money but no sole,  I feel no passion fire the engine just the way it makes the car go. The cross flow has a sole. 

My feelings exactly and the whole point of owning this type of car IMO. The car needs to drive your heart.