engine upgrade

Post any info regarding parts for conversion and swaps.
and any posts regarding swaps help.

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ppyvabw
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engine upgrade

Post by ppyvabw »

I am going through one of my phases where I want to ditch the 3.5 and put a bigger one in my b. There are a few on fleabay at the moment, but I am torn as to what my best option will be.

1st question
I would like to go to 4.6, but I don't want to replace my lt77 box and original b axle. Will the LT77 box and b tube axle cope with a mildly worked over 4.6, I'm thinking not. I reckon the LT77 is good for 300hp ish. There's a school of thought that says mgb axles are unbreakable, except I have managed to break one in a 3.5 :lol:

My other option is a mad 3.9. What's the best thing to do here in your opinion.

2nd question

I've asked something similar ages ago, but then got bored of the idea until I was shamefully burned off the other day by a chav in a souped up mr2. There's a cross bolt 4.0L but it's miles away and has the wrong bits on and a 3.9 that's right next door, with all the right bits on i.e front cover... How much of an advantage is the cross bolt block if i want to make a screamer? Will studs and a girdle be just as effective?

3rd question.
I'd like to inject it. The engines I'm looking at come with injection manifolds, but I want to keep my mgc bonnet. I know the rv8 had a funny shaped bulge over the plenum. Has anyone squeezed such a thing under a normal b or c bonnet? I know nothing about injection systems, are there different ones with different heights or stuff? what combination of stuff could I use? I don't even know what system there are. Any advice at all about this would be usefull.

4th question
What sort of money would a mildly worked over 3.5 fetch with 20000 miles on with some of it's bits on, carb dizzy etc....

Replies much appreciated. Thank you in advance.



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Post by JC. »

MGB axles are solid. Theres a member on here putting 350bhp + through a MGBV8 axle.
Its how you put the power down that is the difference between the axle taking it and breaking.

4.6 V8 will be a laugh. Thats what my BGT is getting.
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ppyvabw
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Post by ppyvabw »

what about the gearbox though?

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ChrisJC
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Post by ChrisJC »

The R380 is newer than the LT77, presumably it's an improvement.....

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Series IIA 4.6 V8
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Post by JC. »

No idea if the LT77 will take it. I converted mine to a 3.5 using an LT77 but decided I didnt like it. I'm putting a powerglide in instead. A TH350/400 would be a good swap too.
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