Big Valve cylinderheads-or not.
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Big Valve cylinderheads-or not.
I am trying to roughly work out if it is feasible to upgrade my heads to give more power.
After talking to Perry I believe the most cost effective way to give a power increase is fit a better cam with porting the heads.
Is it possible to tell if I have a large valve head from a photo as at the moment I don’t want to take the heads off ?
Cheers
Dave
After talking to Perry I believe the most cost effective way to give a power increase is fit a better cam with porting the heads.
Is it possible to tell if I have a large valve head from a photo as at the moment I don’t want to take the heads off ?
Cheers
Dave
1973 MGBGT
1975 MGB V8
I thought I could see the light at the end of the tunnel but it turns out it was a train comming!!
1975 MGB V8
I thought I could see the light at the end of the tunnel but it turns out it was a train comming!!
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Dave,
As far as I can see they look like bog standard heads,
A pair of Stage 1 Econotune heads with standard valve size from peter burgess will yield approx +30--35 BHP without a change of cam and make for a nice free revving engine.
More can be had obviously, depends on what you want and how much you want to spend.
http://www.mgcars.org.uk/peterburgess/page18.html
Kevin.
As far as I can see they look like bog standard heads,
A pair of Stage 1 Econotune heads with standard valve size from peter burgess will yield approx +30--35 BHP without a change of cam and make for a nice free revving engine.
More can be had obviously, depends on what you want and how much you want to spend.
http://www.mgcars.org.uk/peterburgess/page18.html
Kevin.
Hi Kevin
When you say bog standard do you mean they are not SD1 heads?
30 BHP is exactly what I want. It would bring me up to 200 which is as far as I want to go. Would a change of cam (+ followers) give even more power with out losing smooth tickover and give oomph from low revs?
Dave
When you say bog standard do you mean they are not SD1 heads?
30 BHP is exactly what I want. It would bring me up to 200 which is as far as I want to go. Would a change of cam (+ followers) give even more power with out losing smooth tickover and give oomph from low revs?
Dave
1973 MGBGT
1975 MGB V8
I thought I could see the light at the end of the tunnel but it turns out it was a train comming!!
1975 MGB V8
I thought I could see the light at the end of the tunnel but it turns out it was a train comming!!
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- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
they look standard to me, if your car is heavy and an auto box stay away from the typhoon cam, rich
Nightbreed racing, http://www.youtube.com/watch?v=NJoUTZ8UUps
it always helps, have a chat with Paul at v8 tuner, he can advice on cams rich
Nightbreed racing, http://www.youtube.com/watch?v=NJoUTZ8UUps
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Its 3.5 with MGOC ceramic coated block huggers and a twin system.
Perry tuned her up for me and she runs fine but I would like to stop the start-up smoke and get her to breath a bit better.
I plan on porting the head and fitting the later valve stem seals (modding guides) and if recommended, change the cam. Perry has recommended I chat to a chap he knows so I am roughly trying to find out the costs. When I have the spare cash I will go looking.
I have the Mr Gasket 14" by 2" deep round air filter. Do K&N do a replacement and would it be a worthwhile upgrade?
Dave
Perry tuned her up for me and she runs fine but I would like to stop the start-up smoke and get her to breath a bit better.
I plan on porting the head and fitting the later valve stem seals (modding guides) and if recommended, change the cam. Perry has recommended I chat to a chap he knows so I am roughly trying to find out the costs. When I have the spare cash I will go looking.
I have the Mr Gasket 14" by 2" deep round air filter. Do K&N do a replacement and would it be a worthwhile upgrade?
Dave
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- Top Dog
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Dave,
If your getting smoke on start up I would check that the positive crankase ventilation is working properly.
If faulty or not properly installed it causes pressurisation of the crankcase and valve cover areas which causes oil to be forced down the inlet guides.
Re the Air filter yes you can get a K+N but the problem with the Mr Gasket low rider is the filter depth of 2" which is too small and brings the top of the filter casing too close to the top of the carb causing a restriction to air flow. With the amount of space available between the top of the carb and underside of the bonnet being the controlling factor, you are somewhat limited as to what can be done.
To check under bonnet clearance get some platiscine or blue tack and make up three little cones about 2" high and place one at the front of the filter lid and one on each side and then gently close the bonnet the resultant squashed height will tell you the amount of clearance you have.
If you have the offy manifold you may have room for a 2 1/2" filter, V8 tuner has them and you can also filt a K + N extreme top which also a filter and will increase the flow significantly.
Kevin.
If your getting smoke on start up I would check that the positive crankase ventilation is working properly.
If faulty or not properly installed it causes pressurisation of the crankcase and valve cover areas which causes oil to be forced down the inlet guides.
Re the Air filter yes you can get a K+N but the problem with the Mr Gasket low rider is the filter depth of 2" which is too small and brings the top of the filter casing too close to the top of the carb causing a restriction to air flow. With the amount of space available between the top of the carb and underside of the bonnet being the controlling factor, you are somewhat limited as to what can be done.
To check under bonnet clearance get some platiscine or blue tack and make up three little cones about 2" high and place one at the front of the filter lid and one on each side and then gently close the bonnet the resultant squashed height will tell you the amount of clearance you have.
If you have the offy manifold you may have room for a 2 1/2" filter, V8 tuner has them and you can also filt a K + N extreme top which also a filter and will increase the flow significantly.
Kevin.
Kevin
I have started down that route already, with recommendations from yourself and others I have fitted a filter on one rocker and a flame trap and PCV valve into the PCV port on the Webber. It seems to be running fine.
One of the problems is I have a special Filter cover so all I could do is look for a better filter material or a cover that dropped down to lower the base of the filter. I have about 5mm clearance between the cover and the bonnet.
If I really need to I will have to fit an MGC or RV8 bonnet. ( More money though!!!)
Dave
I have started down that route already, with recommendations from yourself and others I have fitted a filter on one rocker and a flame trap and PCV valve into the PCV port on the Webber. It seems to be running fine.
One of the problems is I have a special Filter cover so all I could do is look for a better filter material or a cover that dropped down to lower the base of the filter. I have about 5mm clearance between the cover and the bonnet.
If I really need to I will have to fit an MGC or RV8 bonnet. ( More money though!!!)
Dave
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- Top Dog
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- Joined: Sat Aug 18, 2007 5:09 pm
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Dave,
Souds like you are limited to fitting a K + N Extreme top, you cant really lower the filter More than the Mr.Gasket one anyway, you can always swap your nice MG V8 one over if you intend showing the car.
A MGC bonnet will give more clearance for a 14" round filter, the bulge in the RV8 one I have, does not increase the height at the edges of a round filter,
Kevin.
Souds like you are limited to fitting a K + N Extreme top, you cant really lower the filter More than the Mr.Gasket one anyway, you can always swap your nice MG V8 one over if you intend showing the car.
A MGC bonnet will give more clearance for a 14" round filter, the bulge in the RV8 one I have, does not increase the height at the edges of a round filter,
Kevin.