Is this worth the effort? (ported/polished head)

3rd April 2007, 11:25

Hi,

Considering whether or not I should get a secondhand cylinder head (low mileage) and have it ported/polished, currently have the below minor mods, & if I would see any difference in performance?

4-2-1 manifold
de-cat, s/s zorst
BMC
Dastek/Re-map (to be fitted)
Newman PH1 (258 lift, not wild & to be fitted)

The above is/will on a '00 silvertop 90bhp VTR.

Your advise please as I am very un-sure what I want to do

One thing I am sure about is stopping all mods at this point as its a day to day drive & any further mods I feel will compromise upon this (mpg, rough idle....)

Thx & I hope you can help.
ManC

PS: Thought I'd post my engine bay if it helps in anyway, this is before mods of course :d

3rd April 2007, 11:38

port and polish will be worth it, the flow will be alot better. not sure if you will see bhp gains, but im sure it will have some gains

ever thought about gettin an s engine in?

not sure how much it would be to have the head done proffessionally

3rd April 2007, 12:10

Bought this in a rush and overlooked the VTS

A ported/polished head you looking in the region of £400 not via qep or gmc etc thou, cant afford there high level service, there are other places who do an equivalent service who I intend to approach if I decide to go ahead for this.

Higher flowing head surely should offer a good increase in performance or is that wrong, have to consider my current mods?

ManC

3rd April 2007, 12:15

not too sure, just know that alot of people do it with mods, everythings smoother so it flows better, could help gain extra bhp but not sure, i know spencer has his vts done and he got higher than average bhp on the rolling road for his mods

is yours a 1 plug ecu then?

400 to do that, you could get a vts lump

3rd April 2007, 12:19

i think i heard that flowing the head and doing something else (cant rember what it was thou) can slow you you car down, cant rember exactly what and why but ive deff heard this from someone at a tuning company

3rd April 2007, 12:34

Quote:

Originally Posted by Matt

not too sure, just know that alot of people do it with mods, everythings smoother so it flows better, could help gain extra bhp but not sure, i know spencer has his vts done and he got higher than average bhp on the rolling road for his mods

is yours a 1 plug ecu then?

400 to do that, you could get a vts lump

Yea its the single plug ecu (thankfully)

I know you can pickup VTs lump for around that money but I would have to declare it on the insurance and the increase would be silly, also want to keep "some" resale value and I know it will be near on impossible selling the car with "engine swap" in the description.

@sy_VTR, I think you maybe referring to a badly ported/polished head, or maybe a head that has not been flow benched, in this case you will get all sorts of problem not to say poor performance, the chaps I intend to approach "will" be flow benching mine and have been doing it for quite a while.

ManC

3rd April 2007, 13:26

i have a ported head on my mi16 engine and its otherwise standard other than throttlebodies. On a rolling road it made about 2 bhp more than others with same spec but standard head.

Basically i wouldnt bother unless you have a cam that can utilise the free'er flowing head. I would recommend you find someone thats worked on that engine and can be trusted to not just cut away merrily. Theres a guy down in Cornwall called Mark Shillaber who does some really good work on pugs. Might be worth giving him a call. I think i have his number somewhere.

ps a flow bench can only be used as a guide. it doesnt tell the whole story

3rd April 2007, 14:07

Hi & cheers for the reply,

Hmm seems like alot of effort & cost for an extra 2bhp and as you can see I dont have a very wild cam thus not utilising the higher flowing head, nor will I be boosting. Would still be intresting to see what he quotes for the work, you never know it maybe reasonable...

ManC

3rd April 2007, 14:32

dont bother with the dastek. get a standard ecu remap or standalone.

3rd April 2007, 14:33

cost will be around the £500 mark for a 'good head job'

3rd April 2007, 14:50

Quote:

Originally Posted by williamsvts

dont bother with the dastek. get a standard ecu remap or standalone.

Got the Dastek quite cheap (£80) and the remap will be £250 so all in all it does work out a little cheaper than a ecu remap...

Headwork is reasonably priced but it's establishing whether or not it is merited with my invisiged mods...

ManC

3rd April 2007, 17:22

as kam has said, your cam is not gonna be wild enough to warrant getting it done

3rd April 2007, 17:23

Quote:

Originally Posted by manc

Got the Dastek quite cheap (£80) and the remap will be £250 so all in all it does work out a little cheaper than a ecu remap...

Headwork is reasonably priced but it's establishing whether or not it is merited with my invisiged mods...

ManC

the dastek wont raise your rev limit though so you may not see the full benefit of the cam.

3rd April 2007, 17:24

i would also buy an adjustable cam pulley before the remap.

3rd April 2007, 17:25

i concur

3rd April 2007, 17:28

I'm pretty sure the new dastek (green/silver) version can raise the rev limiter, but I shall confirm this.

Forgot to mention I have a Catcam vernier pulley

ManC

3rd April 2007, 17:29

it cant raise RPM on a saxo. none of the add-ons for it can raise it either.

3rd April 2007, 17:39

oh poo

However the spec of the PH1 cam has a duration of 1k to 5k.. this is within the current limiter which is 6.5k aint it?

ManC