Dilemna

ihatesissycars · Post by **ihatesissycars** » Thu May 10, 2007 5:35 pm

Real steal phoned me up today and said

"Hi Gav, Do you want some of our heads?"

Its decision time!

I'd lost hope that they would come out and went and got some tvr 5.0 griff heads which i guess i can sell on. I've been sent an email with pictures and a dyno graph on a 5.0 bottom end with 10:1 c/r and it made 336 hp at 6k and 351 torque (it doesn't say if its nm or lb/ft). I'm not sure what inlet was used but knowing rs its probably a carb of some sort. The cam was a hydraulic jobbie, not sure the specs of that.

The price is £1100 and i have to let them know by tomorrrow morning.

They'd be going on a high c/r 4.6 initially.

Lets hear your thoughts.

Lewis · Post by **Lewis** » Thu May 10, 2007 5:44 pm

Not that it's much help but if it were - 351Nm equaptes to 260ft.lb.....

I hope it's 351ft.lb, most dyno print outs seem to have that as the standard units.......

1100........Lot of cash, do you think you'll get gains that you want over the TVR items? (How much, by the way

) Could you spend that money on getting the TVR items improved a little and then spread the rest around other areas of the engine for a better overall unit?

ihatesissycars · Post by **ihatesissycars** » Thu May 10, 2007 5:54 pm

These tvr jobbies are as far as rover heads can go apparently (£630). I'm 100% it was lb/ft in that case.

For the 4.6 i need a cam, pistons, followers, pushrods, rocker assemblies, a rebore, a crank main journal grind and a timing chain set.

I'm thinking that if these heads are as good as rs say they are then it'd be practice as i'd future proof that area of the engine should i go up in capacity or improve elsewhere.

Lewis · Post by **Lewis** » Thu May 10, 2007 6:20 pm

Sounds like you're sold on the idea then

If you reckon it's a good buy and will stand you in good stead, I'd go for it

ihatesissycars · Post by **ihatesissycars** » Thu May 10, 2007 6:28 pm

I certainly like the idea of them its just are they worth it over the Griff heads i have. If i can sell them for what i paid for them then the rs heads will cost me £600.

Post by **katanaman** » Thu May 10, 2007 7:22 pm

TVR grif heads can make that power on their own but they are known not to be the best of port shapes so low down revs they tend to loose out a bit. I have heard comments from people in the know that grif heads are actually too big for the road on smaller engines. So its known that grif heads can flow but do the RS heads work any better at lower revs but maintain peak flow? You would need to see the curves and preferably of both sets of heads to know for sure.
For new heads they are a bargain but they are new to market as well so still unproven so a gamble. If you have the money I would get them but keep the grif heads just in case. If you want an engine built on known parts and a proven path then just stick with the grif heads.

In the words of Harry "Do you feel lucky punk"?

ihatesissycars · Post by **ihatesissycars** » Thu May 10, 2007 7:48 pm

I have an excel dyno graph for them on the 5.0. I'd post it up but i don't know how to display it as a pciture, photbucket tells me to get stuffed!

The torque curve is mighty impressive.

kev_the_mole · Post by **kev_the_mole** » Thu May 10, 2007 8:27 pm

Gav,

download Gadwin Printscreen from http://www.gadwin.com/printscreen/ (freeware). Run the program setup and program. Get your graph up on the screen, press Prnt Scrn and the world's your bi-valve mollusc! Crop the resultant pic and upload to Photobucket.

Cheers,

Ian

ian.stewart · Post by **ian.stewart** » Thu May 10, 2007 8:36 pm

The question has not been asked, are the RS heads "AS CAST" or fully ported, If they are raw, there has to be a lot of scope to exceed the TVR heads

Post by **katanaman** » Thu May 10, 2007 8:48 pm

ian.stewart wrote:The question has not been asked, are the RS heads "AS CAST" or fully ported, If they are raw, there has to be a lot of scope to exceed the TVR heads

Sure I read they are cnc machined but that doesn't mean they don't still have plenty left in them. Given that they can use standard rocker gear and all that they must have left the valves in the same place so I guess valve size is the ultimate limitation.
All said and done I don't think RS ever intended them to be a competitor to wild cat heads just better than costing a lot of money on expensive porting work to standard heads. These should be a lot closer to ideal out the mould so end results will be far more repetable.

ihatesissycars · Post by **ihatesissycars** » Thu May 10, 2007 8:49 pm

HairbearTE · Post by **HairbearTE** » Thu May 10, 2007 10:52 pm

Marki as I understand from the head I saw at RS the only CNC operations were the finish maching of the head to correct dimensional spec. There's no way RS have got a 5 axis machine to do the ports like US companies such as Brodix and AFR. If the heads make 330 as cast on a 5 litre then they have to be a good thing because I have seen the as cast ports, and they are not enormous by any means. This would suggest that the numbers are reached through highly improved and effecient design, this in turn would lead me to believe that low down performance in everyday conditions would be vastly superior to the stg 4 griffs. I think its Gavs duty to assume the title of "V8 Forum new technology testing officer" and go get a set!

ihatesissycars · Post by **ihatesissycars** » Fri May 11, 2007 7:00 am

I suppose i should get them then eh!

I'll keep you all posted!

ihatesissycars · Post by **ihatesissycars** » Fri May 11, 2007 8:08 am

It is done! I should get them monday, i'll get some pics up for all to see.

I have some pub bragging material now with these as i'm the first person to buy some, there was a variety of chamber sizes too and i got the smallest ones at 27cc and it could be something like 6 years before they make another set.

It'll be later in the wwek now as they're going to drill the ends to suit my serpentine setup.

ihatesissycars · Post by **ihatesissycars** » Fri May 11, 2007 9:38 am

Their test engine.