Engines in Cob's
Discussion
Why is it that Cob engines sually sit around the 2-300 mark in terms of BHP? What do these engines typically provide in terms of lb/ft ?? I assume they must pull like a train in any gear with low top end ? Or do I have the wrong end of the stick ??
I personally would have thought a tweaked Tiv block would work fantastic in these cars. Or can they not handle the power down ??
Oh, looking into shortly purhcasing a Cob of my own
I personally would have thought a tweaked Tiv block would work fantastic in these cars. Or can they not handle the power down ??
Oh, looking into shortly purhcasing a Cob of my own
Plenty Cobras with 400 hp + around (using small block chev). Depending on the chassis some can handle power OK but not for faint hearted.
300hp about the max economically available for a Rover engine I reckon - could tune up more like a TVR but pricey and the weight saving not as great as you would imagine.
Better to fit a US engine , 350-400 hp and 400 ft-lbs, un-temperamental, £5000 or less. Ford V8 looks better in a Cobra (IMHO), Chevvys are cheaper. Much more HP available for a bit more dosh as well, but if you want to use more than 400 hp in a kit car, get an Ultima not a Cobra rep.
300hp about the max economically available for a Rover engine I reckon - could tune up more like a TVR but pricey and the weight saving not as great as you would imagine.
Better to fit a US engine , 350-400 hp and 400 ft-lbs, un-temperamental, £5000 or less. Ford V8 looks better in a Cobra (IMHO), Chevvys are cheaper. Much more HP available for a bit more dosh as well, but if you want to use more than 400 hp in a kit car, get an Ultima not a Cobra rep.
ok, so talking in terms of driveability, would the car be suited more to the Rover block, or something like a 302 Chevy ?
I must admit, i do prefer the stats on the Chevy and that noise is downright dirty !!!!
i'm just trying to toss up (oooh err) between a Tiv (ala Chim) or replica Cobra. In terms of money, looks, rarity etc.
Anyone help on that front ??!?!?
I must admit, i do prefer the stats on the Chevy and that noise is downright dirty !!!!
i'm just trying to toss up (oooh err) between a Tiv (ala Chim) or replica Cobra. In terms of money, looks, rarity etc.
Anyone help on that front ??!?!?
Been a while since I had either a Cobra replica (GD427 with 302 ford) or TVR (350i wedge).
As I recall, the GD427 was quicker, more reliable despite being homemade, better pose value but had no roof which is a set back if you live in Scotland - never got round to fitting one.
The TVR had a roof which was mostly OK and handled a bit better. Unreliable piece of Sh!t it was however, considering I bought it from new and it was not cheap. Later Chims etc may be better, I don't know .
Big American engines if kept to around 1hp per cubic inch capacity are pussycats, lots of torque at all rpm (up to 5000 rpm), low stress, suits cruising in Cobra fine.
My Ultima has 413 hp from 350 ci and gets to 6000 rpm before cam goes off, just starting to get a bit grumbly around idle but still very drivable. The 500 hp plus engines are pretty rough though.
As I recall, the GD427 was quicker, more reliable despite being homemade, better pose value but had no roof which is a set back if you live in Scotland - never got round to fitting one.
The TVR had a roof which was mostly OK and handled a bit better. Unreliable piece of Sh!t it was however, considering I bought it from new and it was not cheap. Later Chims etc may be better, I don't know .
Big American engines if kept to around 1hp per cubic inch capacity are pussycats, lots of torque at all rpm (up to 5000 rpm), low stress, suits cruising in Cobra fine.
My Ultima has 413 hp from 350 ci and gets to 6000 rpm before cam goes off, just starting to get a bit grumbly around idle but still very drivable. The 500 hp plus engines are pretty rough though.
raks said:
When you say 1hp to CU, what is the conversion on typical US engine sizes then ? ie. 5.7L - ??? BHP / ??? lb/ft
5l=302 cu in. This is the engine in a Mustang and will give a tractable 350bhp without major difficulty/expenditure. A long block good for 350bhp could be found for £2200 via the US. This engine may be stroked to up to 347 cu in and 450bhp is not outside the realms of normally aspirated possibility, although it'll be likely to be 'cammy' and have an idle like a cement mixer.
The next Ford engine 'up' is the 351Windsor (avoid the Cleveland) 351 cu in displacement which is 5.7l. This engine is much bigger and heavier (unsurprisingly) but can be stroked up to 427 cu in, the same size as some of the original Ford big blocks. A 'fast street' 351W with a decent idle and good vacuum would give 400bhp or thereabouts.
Of course, as with anything, it depends how much cash you're willing to put in but a little over 1bhp per cu in should be reliable (only 60bhp/l after all) and reasonable in cost.
Of course, you could go mad
I know someone who has just dyno tested his 347 at over 600bhp 
But it has $30k in... raks said:
Oh, how does the wet weather gear on these things fair up??
Not good. People seem to be able to stop GDs leaking, but the hoods on some of the other kits are little more than get you home rain covers.right, slowly taking this in now.
well i don't think i would sourcing the engine anyway. just looking for the one which would be preferable when i come round to buying a complete replica in the next 2-3 months.
i think a lighter street version of the Windsor sounds right, or indeed the 302 is still ok. Must make sure that I get the engine type info or i'll never know the capacity or power of the samn thing !!!
>> Edited by raks on Thursday 11th December 10:57
well i don't think i would sourcing the engine anyway. just looking for the one which would be preferable when i come round to buying a complete replica in the next 2-3 months.
i think a lighter street version of the Windsor sounds right, or indeed the 302 is still ok. Must make sure that I get the engine type info or i'll never know the capacity or power of the samn thing !!!
>> Edited by raks on Thursday 11th December 10:57
I have a problem with tivs generally being 6'4" tall.
My boss has a tuscan had to go to his house one day and was drooling over it sat on the drive. He opened it up and started her up more drooling ensued. got in. AR5E head squashed against the roof when he said I could take it for a spin I politely declined didn't feel comfortable given the driving position ( head canted to one side and no leg room ) and the fact the roads were a bit greasy.
My boss has a tuscan had to go to his house one day and was drooling over it sat on the drive. He opened it up and started her up more drooling ensued. got in. AR5E head squashed against the roof when he said I could take it for a spin I politely declined didn't feel comfortable given the driving position ( head canted to one side and no leg room ) and the fact the roads were a bit greasy.
spartan_andy said:
I have a problem with tivs generally being 6'4" tall.
My boss has a tuscan had to go to his house one day and was drooling over it sat on the drive. He opened it up and started her up more drooling ensued. got in. AR5E head squashed against the roof when he said I could take it for a spin I politely declined didn't feel comfortable given the driving position ( head canted to one side and no leg room ) and the fact the roads were a bit greasy.
Hmmmm, did the seats not have the removable squabs(?!!) to help reduce height for you extra tall blokes? You should've whipped the lid off
I know what you mean about squashed head though, used to be like that in my Cerbie when I was wearing a helmet at trackdays, I'm a mere 6'1" so God knows how you would cope in one!
Cheers,
Rob
ps sorry for thread digression!
spartan_andy said:
surely there's no issue with a cob as they're meant to be driven topless
The car not the driver but to use a different thread topic if VBH did a cob road test topless that would be a different matter.
Have you not seen Pilgrim's advert in the magazines?
>> Edited by peetbee on Thursday 11th December 14:01
heheheheh !!!
ok, so i get the drift that i could fit with the hood off. but what about with the wet weather stuff ????
reason being, if i get one of these machines, when i take it out in the eve/weekend (which believe me, will take preference over my current run around) i would like to know that i won't get caught in the weather. i'm one of these people where as long as it's dry, it's coming out (regardless of temp !!!)
so with the hood on, am i still ok ?!?!
ok, so i get the drift that i could fit with the hood off. but what about with the wet weather stuff ????
reason being, if i get one of these machines, when i take it out in the eve/weekend (which believe me, will take preference over my current run around) i would like to know that i won't get caught in the weather. i'm one of these people where as long as it's dry, it's coming out (regardless of temp !!!)
so with the hood on, am i still ok ?!?!
Julian64 said:
Where do you go to get 400bhp out of a 350ci Chevy?
I have a cob kit still with the original cast iron head on, and was looking for a turnkey solution?
If you have a rebuilt engine in good nick, flat top pistons, you can probably get close to 400 hp by bolting on a decent pair of aluminium heads (eg Edelbrock/Holley/AFR), Performer RPM manifold, moderate hydraulic cam (eg Comp Cams XE274) and a Holley 770 cfm vac secondary. This should be OK with cast crank and pistons. Ideally your reciprocating assembly should be balanced.
Cost adds up though, and you may be as well to get complete engine built either from one of the UK suppliers or import, particularly if there are any doubts about strength of the bottom end.
I was happy with the build Real Steel did for me although a long waiting list and probably not the cheapest. They did run in and tinker with it on the dyno and result is a very nice engine. If I was doing it again I would go straight for EFI however. That is my next upgrade. Won't make much more power but will improve economy, starting, throttle response and behaviour under cornering/braking loads.
>> Edited by gdr on Friday 12th December 09:06
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