HEAD HELP! PLEASE!

NICKYB

hi all, firstly thanks to BURT for helping out so far getting me through with some basic's.

anything to do with internals and i'm out of my depth so here goes..

been to see someone at a company today that i'm going to be taking my spare head to within the next week to have it cleaned up and pressure checked just to make sure that its ok to carry on with, also hes checking the cams to make sure there worth getting sent to PIPER for to have them re-profiled

basically after this has been done, i've asked and hes fine with doing the skim to lower the compression of it for me if i get the info needed but they wouldn't do the port & polish.

what is the port & polish going to intail? is it worth replacing the valves/stems, etc? (sorry but i really havn't a clue about all this) anything else that needs replacing? or that can be done with the head?

all info will be very helpful to me and any links that you think would be a good read for me to get some info from would also be very helpful, thanks in advance to anyone that can help!

thanks nick

MikeS

they will strip the head down to port and polish - so yeh new stems,u can decoke and lap the valves - cheap and effective

if you got the head off it makes good sense to replace the oil pump and water pump but how far do you go before u think enough is enough lol - by increasing performance of the head your putting more pressure on the rest of the components, so if your oil pump and water pump has done 100k + then it makes sense to replace it

NICKYB

MikeS said:
they will strip the head down to port and polish - so yeh new stems,u can decoke and lap the valves - cheap and effective

if you got the head off it makes good sense to replace the oil pump and water pump but how far do you go before u think enough is enough lol - by increasing performance of the head your putting more pressure on the rest of the components, so if your oil pump and water pump has done 100k + then it makes sense to replace it

thnaks mike, the head is a spare that i got from a scrap car, was told the other week it had around 90K on it but then again i was told the chain snapped but soon realised the crank had gone once i got the head off, its in a right state atm with a serious lack of services.

i'm taking it too the shop and too start with there going to clean it up and just check it over then go from there, my engine that its going on has only done 70K and is very clean and serviced too often too be honest so i'll leave the pumps for now as tring to do this as cheap as poss for now as i'll be having a BIG spend next year.

sorry to sound thick but as for the porting & polishing you say they 'strip the head down', i would be ok doing the exhaust manifold side of the head out to the gasket bore but what other parts do they do?

like i say, i'm very cluless about this and am learning all the time! :shifty:

MikeS

http://cylinderheaddevelopments.co.uk/index.html

looks like u got the head off an old ford escort OHV lol

i used the above company for a redtop head and he stripped it down, chemical cleaned it, lapped the valves back in and skimmed for £100

i then sold the head for like £280 haha

NICKYB

thanks mike, think i'm going to have to have a big read up on all this, when the engine is in one peice i can deal with the outside of it! :lol:

i'll see how it gets on with the pressure testing and go from there!

vocky

that will clean up with a decent wash at the engine shop :thumbup:

NICKYB

cheers vocky!

when i get the head to how i want it, would i need to upgrade any of the block internals or will these be ok for the extra thats done on the head?

also is it worth getting the rocker cleaned up as well or will this just be ok with putting abit of engine degreaser on it?

MikeS

think the bottom end is good for 200 bhp

just look at the SC engines m8 - should be a good gauge of what the rods and pistons can handle

Blue_2_2

MikeS said:
think the bottom end is good for 200 bhp

just look at the SC engines m8 - should be a good gauge of what the rods and pistons can handle

more than that!

the 'bottom end' ranges from 250bhp for the rods/pistons to 500bhp for the crank

MikeS

so you would feel comfortable increasing performance to 250 bhp without touching the bottom end ?

Blue_2_2

The difference between 200 and 250 bhp is HUGE!

200 is achievable for a couple of grand in parts and labour

250 needs ALOT of work to achieve it (no one so far has reached it with a n/a)

JohnnyN has got 257bhp and his engine is still in one piece!

So would i build a 250bhp with a standard bottom end

Yes is the simple answer

MikeS

that's not what i said

in theory would you be happy increasing your engine output to 250bhp without even looking or touching the block considering the possibility that the engine in question has been in his vectra for the past 10 years

i am not questioning how much it will cost or how much work is needed cos i completely agree with you

what nickyb is saying is that would it be oki just to chuck a modded head on to his existing block without touching it and would it handle the performance increase

then yes

are we both agreeing on this ?

Blue_2_2

MikeS said:

what nickyb is saying is that would it be ok just to chuck a modded head on to his existing block without touching it and would it handle the performance increase

then yes

are we both agreeing on this ?

Yes, fit and enjoy!

NICKYB

the head was sat in a chem bath today and then the shop is stripping it all down checking as he goes, then once pressure tested it's coming back to me striped so i can port & polish it, hes going to do the deep parts in his dinner hour for me as he has much better tools (he's glad to be doing something other than skimming morris minor heads all day) so hopfully i'll be seeing some progress with it soon.

MikeS

get some pics

chemically cleaned heads before and after is quite an accomplishment lol

Matt

Looking forward to seeing some after pictures