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ptsrv8
17-08-05, 08:58 PM
Claims of power output seems to be a topic that winds people up on here quite easily.

I get asked quite often how powerful my motor is but I honestly wouldn't know to the nearest 100bhp. :confused:

Please could somebody give me a clue what the output would be?

Chevy 350
Fully rebuilt and balanced
Competition cam - fast road spec
roller rockers
4 barrel Holley
K&N Filter

Thanks in anticipation :thumb: :thumb:

Happy Jim
17-08-05, 09:01 PM
Paul,


Not so easy as you'd imagine, the Chevy came in many vehicles as standard and ranged from sub 200Hp to 350 (ish) HP. You'll need to let the Chevy experts know what it started life as first.

Rgds

Jim

ptsrv8
17-08-05, 09:04 PM
OK - stated life as a 1979 Chevy Malibu, it was imported by a US soldier serving at Greenham Common (not that that bit is relevent!)

adricar2
17-08-05, 09:31 PM
paul
the power the engine will produce is dependant on the type of cylinder head used , and also the compression ratio of the engine amungst other things. for example you can not support 500 bhp with a set of smog heads , the flow on the heads will not support large bhp figures.
the bottom end makes the engine live whilst the top end produces the power.
if you give me all, the details cam timing manifold etc i will run it through my desktop dyno programme for you.

Ricky
17-08-05, 09:34 PM
stock the engine produced 165 bhp, with the few upgrades you have i should think it will be around 200-220bhp, this engine was used in police cars in th states and reached a top speed of around 110 mph.

regards
Jim:finger: and im not a cheve expert:D :D

ptsrv8
17-08-05, 09:54 PM
Adrian,
Thanks for the offer, could you be a little more specific as to what info you need? I am a bit of a nivice in this area :o

Ricky - Are you sure??
I had an Astra with 157bhp, a Supra with 320bhp and a 540BMW with about 240bhp. I know the cob is lighter but it is massively different to any of the above.
0 to 60 appears to be easily under 5 secs (although the wife is usually screaming by then and forgets to stop the stop watch :mad: ) The engine revs freely to over 6000rpm and sounds more like a NASCAR than a police car :confused:

Somebody tell me it aint true ...please... I'll never sleep tonight :thumb: :thumb:

ptsrv8
17-08-05, 09:57 PM
oh yes - and I cant spell either (novice)

Ricky
17-08-05, 09:58 PM
This reading was taken from a dyno in the states out of my american engines book... although the 165bhp was taken at 4000 revs.


sorry:D but i did find out that if this engine is rebuilt with a vortech blower it could produce over 500 bhp:p :p :D

Ricky
17-08-05, 10:04 PM
i can pm you the information you need to put into a desktop dyno,

ptsrv8
17-08-05, 10:15 PM
That would be great Ricky - thanks.

Just been to the garage (10 past 11 at night and working tomorrow - I must be upset) to get the build manual. The engine was rebuild over 10 years ago and had 3327.05 spent on it :rolleyes: Surely that means nore than 200bhp :-( :-( :-( :-( :-( :-( :-(

mylesdw
17-08-05, 10:19 PM
I'd go along with the 220 hp estimate. The reason it feels so different is, as you say, due to the power/weight ratio and because the V8 generates far more torque at low revs than the others you mention.

Happy Jim
17-08-05, 10:22 PM
regards
Jim:finger: and im not a cheve expert:D :D

Clearly...The abbreviated form is Chevy :p

ptsrv8
17-08-05, 10:40 PM
What a downer - anyway I suppose it's what you do with it and not how big it is that counts... isn't that what all us inadequates say :D

Adrain

It has a WEIAND intake manifold (part 2P-180)
Carb is Holley part 3310 - 4 (only for competition / off road use - interesting!!)
Competition cam part 12-206-2 High Energy (0.446 valve lift)
Competition lifters and Magnum roller rockers
some information in build manual about new pistons but not enough to relay any worthwhile info to you.
High performance Chevy exhaust headers

Does that help you to get the calculation? - Thanks either way :thumb: :thumb:

mylesdw
17-08-05, 10:44 PM
The standard engine quoted at 165 hp @ 4000 rpm equates to 216 lb/ft torque. Nothing that you mention about the engine will have changed the torque much but it now revs freely to 6000. If it produces maximum torque at 6000 then that gives just under 250hp at that rpm. However, with standard heads the figure is unlikely to be that high.

ptsrv8
17-08-05, 10:53 PM
Cheers Myles,

All I can say is that if 8mpg average (I know we shouldn't talk about the dreaded consumption) only gets me those sort of output figures I am going to have to think again!

I can see a large investment on the horizen (but don't tell the wife!)

mylesdw
17-08-05, 10:59 PM
That is indeed very poor consumption, I would check that Holley, the ignition timing and the fuel pressure. Mine gives more than 10 mpg on four webers. It dynos at just under 300hp at the wheels.

I suspect that a pair of good aftermarket heads would transform your car!

ptsrv8
17-08-05, 11:03 PM
Thats what I can't understand - it doesn't need transforming - it goes like hell, smokes the tyres in first and second, makes them squeal in third and I get scared in forth :angel:

Maybe it already has after market heads on - I'm really not sure.

Miket
17-08-05, 11:10 PM
Paul

Have a look at the spec on the engine I have for sale in the classifieds, it should give you some idea of whats needed to produce approx 340bhp without spending loads of dosh.

http://www.cobraclub.com/classifieds/showproduct.php?product=528&sort=1&cat=8&page=1

ptsrv8
17-08-05, 11:28 PM
Thanks for that Mike - looks like a great motor.
I'm off on my jollies for a fortnight from tomorrow night and I will be straight into the rolling road upon my return.

I will resurrect this string with the results.

enjoyed the banter - cheers all!

adricar2
18-08-05, 10:34 AM
please can you let me know the deatils on the heads?
size of valves. or at the very least casting numbers.

cheesr adrian

Ricky
19-08-05, 10:23 AM
Clearly...The abbreviated form is Chevy :p

it was late at night.......:p :D

mikey
19-08-05, 12:16 PM
Why does everybody get so excited about BHP figures. For a starter take at least 10% off American figures.

The secret of a good motor is the power and torque curves and where they come in. As somebody previously mentioned to get near 400 HP in a 350 CDI done properly normally aspirated you are looking at spending 10K or more and will have a motor that is a pig dog rat to drive.

A motor with good torque and reasonable HP well sorted will outperform a motor that has simply been geared to achieving maximum horsepower at the very upper rev range limit unless its only driven opn the track.
Mike

Ricky
19-08-05, 12:41 PM
Why does everybody get so excited about BHP figures. For a starter take at least 10% off American figures.

The secret of a good motor is the power and torque curves and where they come in. As somebody previously mentioned to get near 400 HP in a 350 CDI done properly normally aspirated you are looking at spending 10K or more and will have a motor that is a pig dog rat to drive.

A motor with good torque and reasonable HP well sorted will outperform a motor that has simply been geared to achieving maximum horsepower at the very upper rev range limit unless its only driven opn the track.
Mike

charlie, pat, ian and robs engines are producing near or more than 400 bhp built by ken colman.. im pretty sure they spent no were near 10 grand. all there cars are smooth and very reliable , infact pat uses his every day.

regards

Colin GD427
19-08-05, 08:00 PM
Hi

My LS6 Chevy has 398.6 bhp and 381.2ft of torque at the wheels:thumb: and it is so smooth to drive on the open road or in traffic. Just got back from a run to Nurburgring, its a joy to drive. I have had the throttle body gas flowed and high ratio rockers fitted so I could of increased the BHP and Torque. See when I get it back on the dyno.:D

Regards

Colin

Ricky
20-08-05, 11:36 AM
glad to hear you got the car back on the road mate:thumb: now you just need to make up for lost time at elvington, and come the snetterton:D :D i hope that will be the last i have to push your car on the back of a low loader:thumb: :-} :-}


regards

mikey
20-08-05, 06:59 PM
charlie, pat, ian and robs engines are producing near or more than 400 bhp built by ken colman.. im pretty sure they spent no were near 10 grand. all there cars are smooth and very reliable , infact pat uses his every day.

regards

Thats interesting - I thought it was around 10K for a decent motor producing that sort of Horse power from Kenny and I think Rob will have spent at least that even without the supercharger on at present. Correct me if I'm wrong

I'm over at Kennys to get my Barry Grant set up properly so I will ask him his opinion, When last we spoke as he sorted my last motor you could get to around 390 with reasonable spend but going over 400 without a Stroker was serious stuff.

Aparently the Herbert cam with Kenny's profile will deliver around 400 BHP and give a reasonable low end - Kennys running one with Delortos in his Cobra at present.

I have also heard that the LS6's push out good Horse Power thought about one myself, but in the end plummed for a Mowtown that gives quite a bit more power with Torque to suit - but it was expensive.

The point of my post is that many people seem to just want the highest HP and that is not a clever way to go. Its a matter of balancing it with the driveability.

The other point was about the American claims - They recon I should be making around 550 HP but I am sure that it will be more around 500 ish.

Bit like the Performer RPM cam - clains around 400 HP but reasonably you get around 360 if you have done a good job and around 390 if you really go to town.

I guess if you can tell me what chaeap spec gives 400 plus and keeps the motor nice to drive I'd more believe it - I've tried to get there myself in the past with decking and real tight tolerance building withot success. As i say 390 is easy but beyond - good luck.

Mike

osgood
20-08-05, 07:46 PM
Amazing still no posted BHP figure unless I have missed something, Unique Autocraft Python with good range of tune (Auto) 210 BHP at the rear wheels with a loss of 25% through transmision Osgood:angel:

Clarkson
20-08-05, 08:13 PM
Mikey,

Wot's the spec of your engine and what is the BHP??

I hope mine makes the claimed output,There again it's a bit radical. If I don't see a least 400bhp, I will be disapointed. I have a solid lifter crane cam, with 244 and 252 duration .533&.576 with 1.6 roller rockers, 195cc AFR race ported heads, 11.0 comp,Vic jnr intake and 750 mighty demon carb. 3200rpm to 6800rpm. And a NOS Cheater kit:o

Got given a spare 350 block last week and gonna build a 383 for my spare engine.

Clarkson
20-08-05, 08:26 PM
My stock 350 chevy when it was dyno'd 10 years ago put out 200bhp at the wheels with 310lbft torque. Went well,enough to scare my mates in it, but ran out of power at 4500rpm!

Ricky
20-08-05, 11:02 PM
[quote:53e23e7360="mikey"]Thats interesting - I thought it was around 10K for a decent motor producing that sort of Horse power from Kenny and I think Rob will have spent at least that even without the supercharger on at present. Correct me if I'm wrong

i was talking about rob stevens, but im pretty sure that rob stanley hasnt spent that much either, if he has its because of things going wrong ie, blets snapping on the dyno etc... plus he is producing nearly twice the 400bhp we were talking about. :thumb:

regards

mikey
21-08-05, 10:10 AM
Mikey,

Wot's the spec of your engine and what is the BHP??

I hope mine makes the claimed output,There again it's a bit radical. If I don't see a least 400bhp, I will be disapointed. I have a solid lifter crane cam, with 244 and 252 duration .533&.576 with 1.6 roller rockers, 195cc AFR race ported heads, 11.0 comp,Vic jnr intake and 750 mighty demon carb. 3200rpm to 6800rpm. And a NOS Cheater kit:o

Got given a spare 350 block last week and gonna build a 383 for my spare engine.

The engine is a Mowtown 415 with around 10 to 1 CR Victor Junior Air Gap Barry grant 825 CFM with annular discharge Very solid bottom end and a Crower 290 grind which is a level 4 cam solid roller cam (one off full race) 266 overlap. The set up is solid lifters, which is a pain as you need to set them every 200 miles. It cost around 13K but is I suppose a bit hybrid to say the least.

The cam is reputed to be capable of giving around 410 BHP in a 350, but you need to go up to around 400 plus CDI to get a motor that is comfortably driveable.

Reason I went this route is in a fey years when I have got some money left I want to supercarge it as its the only real way you can get the power output and keep torque and driveability. I will belooking for around 750 BHP so I will probably need to seek Rob's experience in beefing up the running gear.

If you are running that profile on the crane cam it may well be worthwhile putting a timing cover with removable plate on using a hex-adjust cam gear as you can usefully bring down the power band to around 900 RPM lower if you advance the cam around 8 degrees. Kenny has them in stock.

You will also probably find that it will want around 16 to 18 degrees initial advance so make sure you have a decent dizzy where you can limit the mechanical advance to give you around 34 to 36 degrees overall (you do this with bushings). Contact me on private message if you want to ru through it.

With regards the cost, rather than argue as I am not sure of the facts and could easily be proved incorrect I will ring Kenny on Monday to find out how much he will build a 400 + 350 CDI for. I will be amazed if it is cheaper than 10 g unless he will do near standard engines now as when you add up the bits he does e.g. smoothing lifter valley and relieving stress point plus balancing etc there is quite a few grand there.

The point is still being missed - I dont want anybody to end up with what I had around 10 years ago without wanting that. I went the HP route assuming that 5.7 litres would overcome the radical cam. What i ended up with was a car that was a pig when queing into car shows and in town was alwys at the beginning of the cam making it very lumpy. I got around 405 BHP but it took some serious work around machining, tolerances and it was developing this above 6000 RPM so the cost of including parts capable of these RPM,s came in.

Within 12 months I had changed the cam for a milder profile, but because the power and torque was delivered more appropriately the car was much faster and more enjoyable anywhere other than on the track.

If you still want to search horsepower without thinking it through then so be it, I was only trying to be helpful by warning against the expensive mistakes I have made.
Mike

robert
21-08-05, 06:07 PM
Thats interesting - I thought it was around 10K for a decent motor producing that sort of Horse power from Kenny and I think Rob will have spent at least that even without the supercharger on at present. Correct me if I'm wrong

Mike

Nowhere near 10K, nearer half that inc supercharger. :thumb:

mikey
22-08-05, 08:03 AM
I assume that you built it yourself then.

Superchrged motor for 5K that,s built with decent gear - are you really telling me thats possible Rob with new parts and thats well prepared.

Shows how wrong I am - I wouldn't touch a motor that is capable of 600-800 BHP that was built on a budget of 5K including the block etc. Would you?

However you may be very good at soursing stuff. As I mentioned I am thinking of Supercharging the Mowtown eventually. Pricing decent equipment and taking out the expense of the Mowtown I would have assumed a budget of around 9000 where am I going wrong.

Mike

robert
22-08-05, 09:06 AM
Mike

You assume wrong, Ken Coleman built it.

The engine cost about 5k to build although I already had the block. The blower and intercooler were extra.

The engine was built, and all the bit supplied by Ken and I dropped the blower off at Andys so he could pattern up the brackets etc.

All in, the engine, blower, intercooler, brackets, belts etc cost around 8K. The engine is only as good as the bloke that puts it together, and in this case, I trust Ken to do a good job. He has done one or two before. :D

Mind you, I have spent a bit more on it since. I have 2 blowers in the garage and a couple of intercoolers whilst trying out different options. :thumb:

tonym
22-08-05, 09:11 AM
If you decide to dispose of your "spare" blowers Rob, send me a mail with price, description etc. :thumb:

mikey
22-08-05, 09:30 AM
Mike

You assume wrong, Ken Coleman built it.

The engine cost about 5k to build although I already had the block. The blower and intercooler were extra.

The engine was built, and all the bit supplied by Ken and I dropped the blower off at Andys so he could pattern up the brackets etc.

All in, the engine, blower, intercooler, brackets, belts etc cost around 8K. The engine is only as good as the bloke that puts it together, and in this case, I trust Ken to do a good job. He has done one or two before. :D

Mind you, I have spent a bit more on it since. I have 2 blowers in the garage and a couple of intercoolers whilst trying out different options. :thumb:

I know, I used to and still read your posts including those whe you first built the beast - I know its a good strong engine and well built which is why to say 5K puts it down to something else which it is not.

If anything I think if asked you would give reasonable advice in relation to cost or how to do things. Indeed I benefited from this via you, Wilf and a few others who were giving sensible advise to new comers like me.

I am not suggesting that others are meaning or trying to mislead, but rather than hearsay I think we need to present knowledge, experience and facts whenever we can. I learnt from experience when I managed to build the big BHP 400. Wrong for the road and expensive - no very expensive mistake.

I am passionate though about not misleading new members that are having to invest their hard earned savings in to there dreams, especially when on a budget which is why I get on my high horse sometimes - and apologies for that. It is too easy to send them in the wrong direction which can result in something which they didn't intend for or has stretched their budget too much.

All the best and thanks for your imput on a great site - even though you do get sticklers like me around sometimes
Mike

Big Thirsty
22-08-05, 10:53 AM
Mikey,

I don't believe you are going wrong, as that does not seem an unreasonable budget to correctly build a supercharged motown blocked engine. You also made some very valid point's in your earlier thread, regarding the quest to achieve high (non blown) bhp figures and the effect it can have on drivability. There are very few roads now in the UK, where you can safely extract peak horsepower from an engine running at 5000 + RPM. There is a whole world of pain waiting for you, when you combine lumpy cams and traffic jams



When we sell an engine based on a particular horsepower level, we know that the performance parts we build into it will give a peak bhp, somewhere in the region of the figures quoted by the US parts manufacturer. We appreciate that in reality, these figures are from an American calibrated dyno with open header systems. In addition, these engines are fully run in whilst being run on better quality pump fuels found in the US.



To answer your question about the cost of building a Chevy at the 400 bhp mark, we recently had one of our 400+bhp Chevy engines tested by Tim Adams. He used standard unleaded fuel to match the comp ratio of approx 9.6 : 1 with a closed header dyno system. Our engine peaked at 400.8 bhp (UK dyno figures) and I would estimate that the yanks would call this an easy 420 +bhp, when using their USA dyno figures. We sell this engine for 5399 including VAT, which is reasonable for a turn key engine, built and blueprinted in the UK, using parts purchased solely from the UK.

Ian

mikey
22-08-05, 11:59 AM
What is the duration of the cam, overlap and at what RPM does it come in at.

Even better do you have the Dyno graph as I am honestly still sceptical about a 350CDI with 400+ that is easy to drive.

When I managed it I had to Deck to zero and cut the pistons and I certainly needed 10 to 1 with the cam profile. It all happened way up the range and the unit was a lumpy bitch in town.

Can't put it down to my building either - I've done too many Ford and lotus Racing engines to build a loose motor.

My knowledge of Chevys is basic but I did advanced vehicle technology at Bolton I.T. (unfortunately in 1970 but you dont forget the principles) and induction/camshaft technology was one of the main areas in the performance improvement section.

Keep it going - I'm genuinely interested and enjoying the debate. You may even turn round what my Tutors taught me.
Mike

robert
22-08-05, 01:59 PM
Mike

The specs on my engine, and the lot came to 6700.

Original block, strip and rebuild, full engine balance etc etc.

Fit 4 bolt main cap conv
Line and bore and hone

Milodon 4 bolt mains
Wisco blower pistons & Rings
Eagle rods
Eagle 4340 crank
Comp Eng bearings/gaskets
Other goodies such as performer rpm heads, vic jnr manifold etc etc.

The cam is a blower cam therefore the duration is quite long, and I have added the FI since.

The engine runs really nicely without the blower, as it is 8:1 comp ratio and produces just shy of 400hp without the blower. There is no lumpy cam, and traffic jams aren't a problem other than the clutch which needs to be a bit beefy to cope with the blown horsepower.

A testament to the engine and the builder is that it did 3500 miles of long hard driving on the Cannonball and only used a quart of oil over that time. :thumb: Thats a darn sight better than my daily driver. :rolleyes:

I have the original invoice and the dyno sheets, bit sad I know, but filed it away in the Cobra file.

mikey
22-08-05, 02:38 PM
Probably that prices have changed over time. To get Kenny to do it now its not even close - I asked him. How long have you had it done for by the way.

Worth reminding him of the spec as he says the way they do that power is in a Stroker and wouldn't go the 350 route. You speak to him regularly have a word then you can help me pass on the advise - good or bad.

Cheers Rob
Guess you dont have to work for a living either - I wish!
Miike

robert
22-08-05, 08:20 PM
The engine was done in 2001. I need to speak to Ken soon, so will remind him. ;) ;)

mikey
23-08-05, 07:56 AM
You dont need to he remembers it well.

I think we are all about agreeing now anyway as I noticed you posted just shy of 400 BHP. I mentioned before that I achieved around 410 BHP which was lumpy as hell but coming down to 390 with a cam change dramatically changed it into a much nicer car.

Regarding price - look at Summit Catalogue the dollar may have come down but I think you may get a bit of a shock at the cost of parts in comparison. I got my Performer RPM heads in 1970 and they cost me 650 from Brian at Repower you are looking at 200 more. Dont know about your cam, but the Crower 290R I use a whopping 130 more - granted its an expensive cam.

I will bow down to the fact that using Eagle Rods and Crank etc can reduce cost if on a budget. but for your set up now you are looking at around 10K or not far short.

Mike

robert
23-08-05, 09:18 AM
I will bow down to the fact that using Eagle Rods and Crank etc can reduce cost if on a budget. but for your set up now you are looking at around 10K or not far short.

Mike

Mike

Just the engine at 400 horses, 6700. Granted, with the blower and intercooler, about 10K however it does put out nearly 800hp. :thumb:

I don't think that you could get an 800hp NA engine that drives nicely for 10K. :D

mikey
23-08-05, 09:33 AM
You are very good at this - your horns are definately longer than mine.

You interested in a job of agreeing fees with our clients. I'll make a fortune and you too.

They will be extatic when they see the fee of 50K and me and you will be extatic when we get the 75K.

And they will believe they have got a discount and provide you with sponshorship for the 2006 Cannonball out of the redustion.

Smiling.
All the best - really.
Mike

robert
23-08-05, 09:54 AM
You are very good at this - your horns are definately longer than mine.

You interested in a job of agreeing fees with our clients. I'll make a fortune and you too.

They will be extatic when they see the fee of 50K and me and you will be extatic when we get the 75K.

And they will believe they have got a discount and provide you with sponshorship for the 2006 Cannonball out of the redustion.

Smiling.
All the best - really.
Mike

Mike

Have done many many contract (protracted) negotiations with the likes of BT, C&W and a whole host of others, had to get good at it to ensure I got the best deal for my clients. ;) ;)

mikey
23-08-05, 10:44 AM
Mike

Have done many many contract (protracted) negotiations with the likes of BT, C&W and a whole host of others, had to get good at it to ensure I got the best deal for my clients. ;) ;)

We need to chat at the next show.

My forte is going out and getting clients and for some reason that I cant fully comprehend I seem to be good at it. oh and innovating on commissions. Diversified Architecture into a hybrid surveying area to do with True Value that now employs abut 32 people after 12 monts.

There must be something that we can innovate on that is going to provide a strong reward. Just think you will be doing the Cannonball in the Mulsanne Turbo with 2 no three blondes in the back seat next year.

Coming back to earth there are probably 3 members rushing for the Henna right now.

Thats made me think - With the sort of membership we have should we not develop a post that searches whether we have the resourse and capability to establish a venture that is going to make us rich. Sorry Rob I know you are already, but I am sure you wouldn,t complain about being richer. You can get others to do the Farm house then.
What do you recon - worh a post.
Mike

robert
23-08-05, 11:19 AM
There was a post about who does what some time ago, or I could look at adding a field to the user information. :thumb:

Mulsanne Turbo, maybe not. A DB9, hmmmmmmmmmmm. :D