Just got back home. Very nice to meet you in person. Once again I would like to thank you for the warm welcome and your time. As expected you have a serious piece of equipment there and boy was it noise at full throttle. We arrived back in the hotel at 00:45, two junctions closed. Also enjoyed the Autosport International the day after.
We too were surprised to see the inlet choking at .400. Will investigate what’s going. Very strange indeed. We even double checked the results on the neighbouring cylinder.
Plans are as followed;
- Find a head tuner with flow bench in my area and take some further
measurements.
- Ask the friendly people at RealSteel for an explanation.
- Get the old Dremel out?
Prior to visiting you we paid JE Developments a visit. To my surprise he had a pair of Merlins laying around. I asked him for his opinion. I noticed he had reworked the intake quite extensively. My goal with the 5.0 and the Merlins is to achieve around 300bhp. John said this would be easily achieved with the Merlins in standard trim. As one should expect of course.
I'll of course keep posted on any progress.
you will get at least 320bhp with rover stage 4 heads for 5.0litre.
I will wait to hear what results merlin gives.. Because i don belive their flow capacity..
Sorry to hear of the long slog back to Birmingham - I really appreciate the opportunity to put the Merlins on the bench.
...
No worries mate. Really appreciate the opportunity to get them measured as well. This is the least I could do for the forum. Put an end to the almost mythical Merlin flow mystery. I didn't expect to stumble across the chocking issue though. The story continues...
Darkspeed wrote:
...
Marcus came up today with what is typically considered to be Stage3 - Ported with the largest valves for the standard seats - 41.5 and 35.5 be assured that Merlins outflowed them by a very significant margin.
Again having another ported/modified head on the bench provided some very interesting results that had me and Marcus scratching our combined heads and swapping heads back and forth. (Careful how you read that )
...
Numbers Andrew we need numbers!
Darkspeed wrote:
...
Lots to do.
Andrew
You sure do! Just let me know if I can be off any assistance. Maybe some a little closer to your location can supply you with some Merlins for further measurements.
Any way very nice to meet you in person and I think this thread will be running for a while.
HairbearTE wrote:
... but i'm now more sure than ever that a home built flowbench and a bit of home r+d is money better spent than just taking a chance on buying someone elses "stage 3" etc. heads.
And perhaps a lot more rewarding to!
Thanks a lot for giving Andrew the opportunity to have a go at your heads!
spend wrote:
Hmmm are flow figures any more than yet another measurement to be put into perspective???
Reversal, cam and complete induction always spring to mind in my case..
Flow figures are just that, flow figures. They are a good way of comparing one set of heads against another in terms of FLOW. Of course there is more than flow with regards to the heads when it comes to producing BHP, the combustion chamber design being one of them.
If I was in the business of porting heads, given the choice I'd rather have a flow bench than not have one.
Last edited by sidecar on Mon Jan 18, 2010 7:41 pm, edited 1 time in total.
sidecar wrote:
I was in the business of porting heads, given the choice I'd rather have a flow bench than not have one.
Absolutely.
My bench owes me around £800 and quite a few man hours - It's already saved me that and I am NOT in the business of porting heads!
I will say this after only a short time taking measurements on the Rover heads that if buying performance heads, always ensure that flow figures for your actual heads are provided. And that the tuner has a baseline datum from which they are developed.
Port flow is not an art -black or otherwise - it's a science and as with every science you need the best and most accurate instruments with which to measure your results.
Simple fact is that the performance of an engine is directly related to its ability to pump air.
No Flow = No go.
And air flow figures are the clearest indication of an engines ability to produce power - Cam induction exhaust are all important factors but wasted unless the head can provide the air to feed the fire. Simples
sidecar wrote:
I was in the business of porting heads, given the choice I'd rather have a flow bench than not have one.
Absolutely.
My bench owes me around £800 and quite a few man hours - It's already saved me that and I am NOT in the business of porting heads!
I will say this after only a short time taking measurements on the Rover heads that if buying performance heads, always ensure that flow figures for your actual heads are provided. And that the tuner has a baseline datum from which they are developed.
Port flow is not an art -black or otherwise - it's a science and as with every science you need the best and most accurate instruments with which to measure your results.
Simple fact is that the performance of an engine is directly related to its ability to pump air.
No Flow = No go.
And air flow figures are the clearest indication of an engines ability to produce power - Cam induction exhaust are all important factors but wasted unless the head can provide the air to feed the fire. Simples
Andrew
I forgot the word "if" in my last post! ..... As in "If I was in the business..."
Its amazing how one small word can change the meaning of a sentence!
Anyway I still think that what you have built is a VERY useful tool.
Great stuff guys and keep it coming, Darkspeed where are you located, I may have a set of hogged out heads to check over. Off season so no need to rush the job. I am hearing about what I expected to hear so far, although would love to solve the choking problem. Thanks again.
Doable then, now I have to find the heads . Although opened up massively they are still on standard valve sizes so may expose or confirm a few other myths. Is there any way on a flow bench to replicate forced induction? I have several vague ideas regarding the denser air mass in a supercharged application. I do believe the density of the mass must affect flow in subtle ways if not in more obvious ones. Will keep you posted.
So do we need a baseline on some Wildcats for comparison? I have a pair in the garage that I haven't got round to fitting yet and am not too far away (in redditch).
Only Stage I's, I was advised against Stage II's by Ian for a road car. However, even they look HUGE compared to my stage4 Rover heads. I'll post some side by side pics when I get a minute.
So do we need a baseline on some Wildcats for comparison? I have a pair in the garage that I haven't got round to fitting yet and am not too far away (in redditch).
We arrived back in the hotel at 00:45, two junctions closed.
Also enjoyed the Autosport International the day after.
) 
Just let me know if I can be off any assistance. Maybe some a little closer to your location can supply you with some Merlins for further measurements.
..... As in "If I was in the business..."
