SCCA EMod MGB GT V12 Build

tuna55 wrote: Think of it like this. You're 80 and talking to your grandkid about cars, and he would love to enter the 205X Challenge. You tell him one of two stories: A) So I once put a Jag V12 in an MGB GT and raced it. Yeah, it overheated at first and it spun a few bearings, so I rebuilt it and then it made 100 hp more than stock and kicked ass. I may not have won any championships, but the build process was amazing and I actually still have it... B) So I once put a Jag V12 in an MGB GT and raced it. Yeah, it overheated at first and it spun a few bearings, so I dropped in a 302 instead. I got bored a few months later and bought a beige Camry. Still have that Camry, want to see?

This is my perspective on it. At the end of it all, you're doing this for fun and bragging rights. You're not going to make ANY money by winning Nats. This is all for personal enjoyment, just keep that in mind.

loosecannon wrote: I like the way you think. A friend is giving me a 5.0 that has a few go fast items on it and it would bolt directly to my T5-it's hard to argue with free.

I was going to say stick with the V12, but it's really difficult to argue with "free engine". If you stay V12, I'm on the "rebuild the one you have" boat. Any used motor may have the same kind of problems that this one did. Or worse yet, different ones. Like the other guys said, at least you know where this one's been..

friedgreencorrado wrote:

loosecannon wrote: I like the way you think. A friend is giving me a 5.0 that has a few go fast items on it and it would bolt directly to my T5-it's hard to argue with free.

I was going to say stick with the V12, but it's really difficult to argue with "free engine". If you stay V12, I'm on the "rebuild the one you have" boat. Any used motor may have the same kind of problems that this one did. Or worse yet, *different* ones. Like the other guys said, at least you know where this one's been..

The V12 I have still has sentimental value. I can take the time to pull it apart, clean it all out and put it back together with high compression pistons, cams and Webers. For now, I need to get my car ready for Nationals and I think a free 5.0 is the way to do it.

In reply to loosecannon:

I vaguely remember the Miata v12 guy talking about how tolerant those motors were of excessively high compression due to some design factor. Is that something you have heard?

MrJoshua wrote: In reply to loosecannon: I vaguely remember the Miata v12 guy talking about how tolerant those motors were of excessively high compression due to some design factor. Is that something you have heard?

The V12 bottom ends are incredibly tough. Even with all the abuse I put mine through, the crank journals are perfect even though the bearings are screwed. The pistons need to be replaced if running high compression but the rest of the engine is pretty robust. Even in stock form, they are good for almost 8000 rpm (with the right cam/springs)-it's insane.

This morning I pulled the exhaust, spoiler, splitter, bumper and fenders off so pulling the engine will be easier. I also bolted the bearing caps and oil pan back on the engine so I don't lose anything. I may rebuild this engine some day and make it into a real screamer with high compression pistons and good cams.

Ive never been a blue oval guy, but the price is right, and parts and literature should be practically growing on trees. I think the swap was the right choice given the circumstances, and I think youll be happy in the long run. The fit to the existing trans is an extra treat as well. Please keep us posted!

If you need parts, I happen to know that ThunderCougarFalconGoat in FL has a new racing cam, rebuilt E7 (5.0HO) heads, and some other goodies for a 302 as I gave all of it to him

He's in a selling mood, too.

Oh, I have an X303 cam if you need it - aggressive high lift - as in it probably needs reliefs in pistons... yours for shipping if you could use it.

oldtin wrote: Oh, I have an X303 cam if you need it - aggressive high lift - as in it probably needs reliefs in pistons... yours for shipping if you could use it.

I will keep that in mind, thanks :) The cam in it now is a Ford Racing 331 grind, which I think is pretty aggressive. What I need is a better intake manifold.

If it has stock cast heads - well, aluminum aftermarket are best flowing - to make do if it hasn't been done is opening up the exhaust ports - that is the restriction point of getting a 302 to flow. Otherwise, an edelbrock performer air gap manifold and 1405 or 1406 carb suit it well (600 cfm) on a budget. 1406 is the same as the 1405 with electric choke.

oldtin wrote: If it has stock cast heads - well, aluminum aftermarket are best flowing - to make do if it hasn't been done is opening up the exhaust ports - that is the restriction point of getting a 302 to flow. Otherwise, an edelbrock performer air gap manifold and 1405 or 1406 carb suit it well (600 cfm) on a budget. 1406 is the same as the 1405 with electric choke.

To save money on the top end look at Summits new manifolds and carburetors.

It's an efi engine and I have no plans to go back to carbs...EVER! ;)

loosecannon wrote: It's an efi engine and I have no plans to go back to carbs...EVER! ;)

phew...glad to hear you say that lol

loosecannon wrote: It's an efi engine and I have no plans to go back to carbs...EVER! ;)

Waitaminute... 2 days ago, you mentioned Webers on the next iteration of the V12.

Could be Weber-style sidedraft throttle bodies.

Like the ones from Jenvey, Extrudabody or TWM Induction. Simple way to have the advantages of ITB's without the hassle of tuning carbs or building your own manifold.

Ian F wrote:

loosecannon wrote: It's an efi engine and I have no plans to go back to carbs...EVER! ;)

Waitaminute... 2 days ago, you mentioned Webers on the next iteration of the V12.

You caught me. What changed is that I my tow vehicle (Suburban) is having trouble pulling my trailer with a headwind, so yesterday I got a Superchips programmer. I programmed the EFI and it runs better and has more power, I didn't have to change jets or touch the distributor! I was just reminded how much carbs suck.

tuna55 wrote: Think of it like this. You're 80 and talking to your grandkid about cars, and he would love to enter the 205X Challenge. You tell him one of two stories: A) So I once put a Jag V12 in an MGB GT and raced it. Yeah, it overheated at first and it spun a few bearings, so I rebuilt it and then it made 100 hp more than stock and kicked ass. I may not have won any championships, but the build process was amazing and I actually still have it... B) So I once put a Jag V12 in an MGB GT and raced it. Yeah, it overheated at first and it spun a few bearings, so I dropped in a 302 instead. I got bored a few months later and bought a beige Camry. Still have that Camry, want to see?

My wife and I aren't having kids so that's not an issue but I think the story I would tell is more like how I built a kicka$$ race car with a Jag V12 but when I blew that up I had to make do with a V8 and won Nationals anyways ;)

I removed the final bits and pieces getting in the way of pulling the engine today so now all I have to do is get my engine hoist and pull out the V12. There should be lots of room in there for the V8, maybe I can add a trunk for holding our helmets? ;)

Such a shame to see her barfing her kibbles and bits. But its gonna be worth it. Pretty nice to be able to basically break down the whole front clip to yank the mill. None of that pesky painted body gettin in the way. Why cant all cars be built like race cars.

I talked to the extrudabody folks a while back. The budget version - use a cobra lower intake - add a flange with 8, 90* curved tubes - alternating which direction they go - add ITBs to other end of tubes - maybe a couple of sets of motorcycle itbs??? I'm throwing all the ideas I wanted for mine that don't fit in a challenge budget.

I think I'll just stick with something traditional like GT40 upper and lower intake, chip, underdrive pulleys and headers.

Must be an old engine pic- no pink valve covers.

I hate to see the V12 go. Maybe you can put it to the side and go through it while running the car with the V8?

It took quite a while but I finally got the Ford 5.0 I'm using out of the vehicle it's been sitting in. The engine is a mess with all it's emissions garbage still attached and a layer of rust on every surface but it was free and does run really well so I can't complain too much. Just to get an idea of how it will fit, I hoisted the V8 into the space freshly vacated by the V12 and it looks like everything will fit ok. There will be a bunch of fab work required but I think I can handle it.

loosecannon wrote: There will be a bunch of fab work required but I think I can handle it.

I don't know, have you done fab work before?

teeheehee