Jag mk2

[barchetta_boy]

Is it me or is this seriously cheap?

http://www.carandclassic.co.uk/car/C437448

Joel

[Flatinfourth]

Could be cheap, but ALL Mkiis need very careful inspection. if the rear spring housings have been repaired badly or are due soon, or there are patches on patches anywhere, it could easily be a nightmare. it's not hard to think of a few repairs that add up to that purchase price.

Might be a lucky find, so check it out!

[lowdrag]

It's also cheap because it is a 3.4, not 3.8. The 3.4 is without doubt the best of the Jaguar engines and while a little less powerful on paper is the smoothest and just as usable in real life. That doesn't mean though that a full investigation with screwdriver and magnet is not required!

[barchetta_boy]

Interesting. Why do you say the 3.4 is better?

[lowdrag]

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

[a8hex]

lowdrag said:

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

That still looks decidedly cheap.

[jith]

lowdrag said:

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

You are right on the button there lowdrag. The 3.8s tend to suffer a certain amount of piston slap that makes them slightly rougher and noiser than the 3.4 when pushed hard

A 3.4 with a straight port head, 9:1 pistons, a lightened flywheel and 2 inch carbs is the one to have.

J

[VetteG]

jith said:

A 3.4 with a straight port head, 9:1 pistons, a lightened flywheel and 2 inch carbs is the one to have.
J

I well remember my old mans 'S' type with this spec of engine. Wonderful!

G

[Bebee]

Sold how much was it?

[a8hex]

jith said:

lowdrag said:

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

You are right on the button there lowdrag. The 3.8s tend to suffer a certain amount of piston slap that makes them slightly rougher and noiser than the 3.4 when pushed hard

A 3.4 with a straight port head, 9:1 pistons, a lightened flywheel and 2 inch carbs is the one to have.

J

In a Mk2 wouldn't the B head be a better bet? The increased swirl of the squirrel port head tended to mean the peak torque was usefully lower down the rev range. The straight port head really comes into its own at higher revs.

[jith]

a8hex said:

jith said:

lowdrag said:

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

You are right on the button there lowdrag. The 3.8s tend to suffer a certain amount of piston slap that makes them slightly rougher and noiser than the 3.4 when pushed hard

A 3.4 with a straight port head, 9:1 pistons, a lightened flywheel and 2 inch carbs is the one to have.

J

In a Mk2 wouldn't the B head be a better bet? The increased swirl of the squirrel port head tended to mean the peak torque was usefully lower down the rev range. The straight port head really comes into its own at higher revs.

Good point a8, but I think it comes down to what you want from the engine. I always thought that these engines really needed 2 inch carbs to maximise their performance, and the straight port head simply helps the gas flow. I have never really noticed a lack of torque with a conversion like this, although it might be the case on an automatic. Mind you most drivers who would prefer an automatic MK 2 probably wouldn't want the extra power anyway.

J

[a8hex]

jith said:

a8hex said:

jith said:

lowdrag said:

Power difference not great and much much smoother than the 3.8. Everyone seems to want to buy the big cojones and overlooks the just-as-good 3.4 so it is far better value.

You are right on the button there lowdrag. The 3.8s tend to suffer a certain amount of piston slap that makes them slightly rougher and noiser than the 3.4 when pushed hard

A 3.4 with a straight port head, 9:1 pistons, a lightened flywheel and 2 inch carbs is the one to have.

J

In a Mk2 wouldn't the B head be a better bet? The increased swirl of the squirrel port head tended to mean the peak torque was usefully lower down the rev range. The straight port head really comes into its own at higher revs.

Good point a8, but I think it comes down to what you want from the engine. I always thought that these engines really needed 2 inch carbs to maximise their performance, and the straight port head simply helps the gas flow. I have never really noticed a lack of torque with a conversion like this, although it might be the case on an automatic. Mind you most drivers who would prefer an automatic MK 2 probably wouldn't want the extra power anyway.

J

The HD8s and an opened out inlet manifold certainly help on a 3.4, at least it did on my 150. Warren Pearce did a triple carb manifold for the "B" head back in period because he found that for the Mk2 it typically gave better lap times, even though the straight port head gave more power. It's really the area under the in gear torque curve that gives you the performance, and by spreading that out you can improve things. The lighter cars like the E-Type gained significantly from the improved high speed gas flow of the straight port. But Mk2s and XK150s are heavy.

[XJ Flyer]

That's probably the best spec for a Mk 2.

www.youtube.com/watch?v=sHP-eijFfOE

Edited by XJ Flyer on Saturday 28th September 17:49