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So what engine do I have?

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drooartz

drooartz

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So the new engine is on my garage floor now, and I'm taking some inventory to figure out just what I've got. It's an 18V (18V801AE-L6793) which I believe is a '76 low compression. Most recently it came out of a 1971 MGB. I did check, and the engine does have what I'm pretty sure are the early style square engine mounts.

What else should I be looking at? How do I tell what head this has? Anything is possible after all these years. What else might be a gotcha for putting this into my MGB (November '70 build)?

Also, a non-OD transmission came with it. Are there any useful things I should pull off of it? I've no need for a non-OD tranny, but would like to know what's worth keeping before I get rid of it.

mgspareengine.jpg
 
Drew, If it came out of a 71, it has to have the early mounts!
The 4 spd, non OD transmissions aren't worth much as far as the market goes, I have a couple of good ones, an early and a late one. If someone offered me 100 bucks a piece, it's theirs.
I don't have my engine chart in front of me, but I'm sure someone will chime in and identify the engine for you. PJ
 
Drew -

According to Clausager's book (Original MGB), the 801 prefix engines ran from June, '75 thru June '76, with numbers from 101-14801. Yours (6793) would be in the first half of that production.

The head for those engines had a new, smaller intake valve, and was set up for unleaded fuel, and catalyst exhaust; no overdrive.

Hope that helps.
Mickey
 
Thanks, Mickey. Now the question is, do I use that head or should I try and find a different one? Does the valve size matter? Is that smaller than the early heads? I've much to learn.

Paul, My friend's car is modified, so I didn't want to assume *anything*, just never know what could have been modified. I know a lot more about the smaller A-series engines than I do the B-series, time to educate myself.
 
Drew, To find out about what mods can be done to the engine, such as head change, or even if it's necessary, contact Hap Waldrup. I know no one who knows more about 1800 series engines and what can and can not be done with them. PJ
 
Yep, size matters. (OK - get your noggins outta the gutter! :angel: ) Engines need to breathe - both intake and exhaust. Like Paul, I'll leave the particulars to those that know the specifics better than I do.
 
IMO, the 18GB was the last stout incarnation. Emissions standards and cost cutting (skimping on materials) eviscerated the later versions.
 
I will have to chat with Hap at some point. As to valve size, I did find out that these "smaller" valves are the same size as the 18G engines -- went up with the first of the 18V engines, then dropped back down with this one.

That assumes, of course, that this is the original head for this block. Have to look deeper to figure it out.
 
Any of these engine can be made better, bigger intake valves in the cylinder head is no big deal, this can easily be done to any of the MGB head, i do it often, in fact, i hardly ever build a cylinder head with the 1.56" intake valves, almost always opting for the 1,625" intake, or 1.70". The connecting rods will be the 18V press fit rods, they are thelightest of all the MGB rods, and I quite often convert earlier 5 main enginje to this connecting rods, over the 1000 gram angled rods. The crank if form 1 76, could be the flat sdie steel crank, but could also be the cast cranks, really doesn';t matter either one are fine for street, street performance use. it probably has a single row timoing chain set up, but in rebuild it can repalce with th duplex set up. Tye ehad will probably be a CAM1106, this is the most prone MGB to cracking, they get the normal exterioir sprk plg side crack, but the also are know to crack in the exhaust seat area, if it is crack free, then it as good as nay of the other MGB head, as for rebuilding.


WhenI built the 1900cc engine for my 67 GT street car, I used a combination of MGB engine parts to come up with the engine, because the car was a 67, I wanted it to look the part from the outside, so I stayed with the 18GB block, and pre smog 12G1326 cylinder haed, so it looked the way a 1967 engine would have looked, but the origianality soon ended there. It got a flatside steel crank from the middle year cars, 18V rods from the later year cars, later style valve cotter and retainers allowing me to take advantage of bigger intake valves. So when people ask , which year was the best MGB, as for as the engine, I tell them , "well it's a little of all of them, and none of any one of them" :smile:


I read alot of stuff on the forums, that make me go hmmmmmm. One being, "I scored a big valve head", when any MGB head can be a big valve head. The next one is people often think new replacment parts are inferior to what the facotry used, but in almost all cases afermarket parts are not just better, they are ALOT BETTER, examples are gaskets, especially head gaskets, pistons and rings, cams, lifters, fasteners, valves , valve springs, valve guides, valve seals, rear seals, the list goes on and on. Even if you were just rebuilding a MGB to exact stock, which there is no good reason to do that, because performance enhancments can be had without spedning one more dollar, especaily if you need to replace the cam, pistons and resurface the head, right there you can gain 20% and never spend a extra dollar,and use better parts than the factory ever did. For the most part MGB engine parts are dirt cheap, the only exception if you want good qauilty is the cam and lifter, this is good place to spend a little extra, there si alot of junk cams and lifter for seal, one must be aware of this, it could easily cost you a early failure.
 
Thanks for the info, Hap. I checked, and this spare engine does have the CAM1106 head as expected. If nothing else, it will be educational to do the tear down, inspection, and measuring.
 
Drew, here's a plan for that engine, get the head peessure checked, if it is good, it worth something to later MGB owner, these were the heads most prone to cracking, so if it is good, its worth a couple hundred dollars. Save the 18V connecting rods for your orignal engine rebuild, if it has the flat side steel crank, I would recommend using in your future rebuild as well, you probably have the early steel crank in that engine, the flat side is a better crank. You can then clean up, and sell the remainder of the engine as parts.

This engine core can actually give you ways to improve your 1970 engine, by using some of the internal parts from this engine.

One tip on taking a MGB engine apart for some odd reason they do not number the rods, so make sure you number both the rod and cap on each rod, you can do this as simply as using a center punch and hammer, one dot equals #1 rod, 2 dots equals #2 rod, and so on , make sure to reinstall the cap to it's matching rod as you are disassembling
 
Thanks for the tip, Hap. Will be interesting to see what is actually inside this engine -- if there are pieces that will be better than what I have in the car now, that's a nice bonus for a free engine.
 
Will do, John. Been too cold to do any work out in the garage these past couple weeks, so the parts are just sitting out there.
 
Yeah, what Hap said
 
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