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cylinder head replacement vittesse mk 1

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hello guys got a mk 1

Vitesse  and just bought tuning standard triumphs by david vizard. now he states that a 2.5 litre cylinder head

can be used on my engine i did not think this possible. some one stated in the distant past that not even a mk 2 head

could not be fitted or are they wrong i need to get as much power out of this motor as poss as i want to race

its a saloon with origional over drive by the way D L O 

any advice would appreciated 

cheers mick

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I'm surprised to hear that someone as guruistic as Vizard would say that.    The Mk1 and 2 had different studs, as well as a very different layout of ports.     2.5L head on Mk.2, yes, but you would either need to fit domed pistons (as Triumph did) or skim a lot off the head to restore compression.   To race the heavy saloon, a 2.5 engine, preferably Pi, would be best - you'll not get far with a Mk1 2L.     What series do you plan to go into?

JOhn

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The Mk1 engine uses the same basic block as the Mk2/2.5 with the same bolt pattern. However, the Mk1 has 3/8” UNF studs and the Mk2 has 7/16” UNF so Mk1 block needs drilling out and re-tapping to use the Mk2 heads.

There are two thicknesses of Mk2 head. For a 2L engine with flat topped pistons you need the thin heads @3.3”. 
 

The more common thick heads are 3.4” or more and used on 2.5s or 2.0 with domed pistons. You don’t want domed pistons.....

Perfectly possible to tune the Mk1 head/engine. The late Oldtuckunder formerly of this parish had a solid 120bhp from his which brought him considerable success on the hills

 

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19 hours ago, JohnD said:

I'm surprised to hear that someone as guruistic as Vizard would say that.    The Mk1 and 2 had different studs, as well as a very different layout of ports.     2.5L head on Mk.2, yes, but you would either need to fit domed pistons (as Triumph did) or skim a lot off the head to restore compression.   To race the heavy saloon, a 2.5 engine, preferably Pi, would be best - you'll not get far with a Mk1 2L.     What series do you plan to go into?

JOhn

Hello John and Nick thanks for the info in reply i just wanted to race in a classic car series that has a two litre section hence the need to tune up what i have

got instead of just slapping in  a big lump from another motor that is not my style. whilst  obviously trying to create short cuts which do not seem

to be working

mick.

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I would stick with tuning the 2L as is and sorting the rear suspension. Roger may still have a camber compensator going spare......

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I have a plan to put a skimmed MK2 head on a MK1 short motor at some point, be rude not to as I have the bits, should be good for revs and aftermarket manifolds/efi...

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Mick, Last few years, there were several Triumphs racing in the CSCC's Swinging 60s series (I don't name

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21 hours ago, Nick Jones said:

I would stick with tuning the 2L as is and sorting the rear suspension. Roger may still have a camber compensator going spare......

Hello Mick

                  Yes I have a Camber compensator looking for a new home!

Get in touch if interested

Roger

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On 7/30/2020 at 4:51 PM, Nick Jones said:

I would stick with tuning the 2L as is and sorting the rear suspension. Roger may still have a camber compensator going spare......

hello mate thanks for your contribution i will be contributing some money to this site but i have advise from a few of you guys 

and i do not know who to respond to first or does it not matter dont want to put any ones nose out of joint

this bui;ld is crucial to me i need every support going this starts during the minors strike

 

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On 7/29/2020 at 6:46 PM, Nick Jones said:

The Mk1 engine uses the same basic block as the Mk2/2.5 with the same bolt pattern. However, the Mk1 has 3/8” UNF studs and the Mk2 has 7/16” UNF so Mk1 block needs drilling out and re-tapping to use the Mk2 heads.

There are two thicknesses of Mk2 head. For a 2L engine with flat topped pistons you need the thin heads @3.3”. 
 

The more common thick heads are 3.4” or more and used on 2.5s or 2.0 with domed pistons. You don’t want domed pistons.....

Perfectly possible to tune the Mk1 head/engine. The late Oldtuckunder formerly of this parish had a solid 120bhp from his which brought him considerable success on the hills

 

 

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20 hours ago, rogerguzzi said:

Hello Mick

                  Yes I have a Camber compensator looking for a new home!

Get in touch if interested

Roger

Hello Roger thanks for the offer i will gladly buy this off you just name your price mate.

i do actually have a snide convertable which already has one fitted

but i need to sell it to make room for the race car mega build and it is the only redeemable attribute of this sad mess of a car

first purchase got drunk went on ebay . so knowing that if you still want to sell then i will buy 

mick

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On 7/30/2020 at 5:20 PM, spider said:

I have a plan to put a skimmed MK2 head on a MK1 short motor at some point, be rude not to as I have the bits, should be good for revs and aftermarket manifolds/efi...

thanks for that mate getting on it straight away.

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On 7/30/2020 at 5:20 PM, spider said:

I have a plan to put a skimmed MK2 head on a MK1 short motor at some point, be rude not to as I have the bits, should be good for revs and aftermarket manifolds/efi...

Not sure what advantage you are seeking here?  It is true that some of the very early Mk1 2L had different bearing sizes (more like the 1600) and some claim that these are more free-revving.  However, these are fairly rare and parts like bearings are harder to find.  I'd also be slightly doubtful whether there is really any actual useful advantage.  Externally you can tell these engines by an external breather on the block by the oil filter.  Not sure whether they were ever fitted to the the VItesse 2L but they do turn up in early Mk1 GT6 and 2000 saloon/estate.

The later, and much more common Mk1 2L have a bottom end which is pretty much identical to the Mk2 2L and, as I said further up, the blocks are even interchangeable bar the head stud size.  BTW, some Mk1 users do have their heads and blocks drilled / re-tapped to 7/16" for the beefier studs to help prevent head gasket failures.  These later blocks are interchangeable with 2.5 blocks (detail differences on the first ones) and share the same bearing sizes as the 2.5s and also all the large crank 1300/1500 4 cyl so parts availability is much better.  You can also get aftermarket rods for these including the decent and reasonably priced MaxSpeeding ones.

As regards using 2.5 heads on 2L.  It is possible.  You can do it by using domed pistons as Triumph themselves did on the 2L engines after about 1973.  THis is a bean counter solution though, not an engineering solution and not desirable for a performance engine.  The other way is to skim them down.  It's a BIG skim though with a fair risk of "striking water" and scrapping the casting.  Far better to start with a 3.3" 2L head if you can find one.  Valves sizes are the same.  In fact, it is some of the later, thicker heads that have the smaller exhaust valves to reduce the risk of cracking between the valves.

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Hello Mick

                  It is this type so not sure it will fit your car!

http://www.spitlist.info/CamberCompensator.html

If others say it will fit its yours for about half of what a new one would be

Roger

ps I have a Chris Witor can shaft with the extra lift and a set of cam followers with the oil hole and phosphated all brand new and a set of new push rods if you are interested

This type of cam with 6 branch exhaust and a large valve head (MK1 2lt) was making 122BHP on this 2lt Vitesse!

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10 hours ago, Nick Jones said:

Not sure what advantage you are seeking here?  It is true that some of the very early Mk1 2L had different bearing sizes (more like the 1600) and some claim that these are more free-revving.  However, these are fairly rare and parts like bearings are harder to find.  I'd also be slightly doubtful whether there is really any actual useful advantage.  Externally you can tell these engines by an external breather on the block by the oil filter.  Not sure whether they were ever fitted to the the VItesse 2L but they do turn up in early Mk1 GT6 and 2000 saloon/estate.

The later, and much more common Mk1 2L have a bottom end which is pretty much identical to the Mk2 2L and, as I said further up, the blocks are even interchangeable bar the head stud size.  BTW, some Mk1 users do have their heads and blocks drilled / re-tapped to 7/16" for the beefier studs to help prevent head gasket failures.  These later blocks are interchangeable with 2.5 blocks (detail differences on the first ones) and share the same bearing sizes as the 2.5s and also all the large crank 1300/1500 4 cyl so parts availability is much better.  You can also get aftermarket rods for these including the decent and reasonably priced MaxSpeeding ones.

As regards using 2.5 heads on 2L.  It is possible.  You can do it by using domed pistons as Triumph themselves did on the 2L engines after about 1973.  THis is a bean counter solution though, not an engineering solution and not desirable for a performance engine.  The other way is to skim them down.  It's a BIG skim though with a fair risk of "striking water" and scrapping the casting.  Far better to start with a 3.3" 2L head if you can find one.  Valves sizes are the same.  In fact, it is some of the later, thicker heads that have the smaller exhaust valves to reduce the risk of cracking between the valves.

After building up my nice 2.0L and my 2.5L motors I will have a lot of parts left over, early saloons and a domed piston GT6 mongrel motor,  so thought I would build something up with whats available. A budget build, as much as is possible, to make a pile of stuff useful. I have the same outlook as yourself Nick in as much as improving stuff at minimal cost by using what's available. I don't think cheque book engineering would be much fun even if it were a possibility. :ermm:

 

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Well, I can certainly relate to that, though I fear that the pool of parts left in my garage has been too well picked over already to yield a half decent engine without fairly significant extra investment......

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On 8/1/2020 at 1:55 PM, rogerguzzi said:

Hello Mick

                  It is this type so not sure it will fit your car!

http://www.spitlist.info/CamberCompensator.html

If others say it will fit its yours for about half of what a new one would be

Roger

ps I have a Chris Witor can shaft with the extra lift and a set of cam followers with the oil hole and phosphated all brand new and a set of new push rods if you are interested

This type of cam with 6 branch exhaust and a large valve head (MK1 2lt) was making 122BHP on this 2lt Vitesse!

Hello Roger my problem at the moment is i am being bombarded with too much info i know more about lammbretor 

than any four stroke i just want some one to make that gt6 mk 3 in my rear mirror to get smaller and smaller

do you think that could ever happen . plus i think there is another option for rear suspension  to replicate the lotus elan 

have you heard of that one my friend 

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