Engine and Transmission Tech

The height would depend on the intake of course. The width is a function of the deck height only and that should be 0.583 to 0.590" according to TAPerformance. Meaning the extra width should be 0.824" if my math is correct. The extra height exclusive of the intake would be half that or 0.412". However, using port spacers to adapt a 215 intake will add another 0.412" making the total close to Mike's stated 3/4".

Jim

Large journal/small journal ? What is the first motion of deflection ? I say the crankshaft is. Given the same load/stress the small journal will deflect more. Will the .100" increased wall thickness of cast aluminum, around the small journal crank, without cross bolted mains, make the bottom end/bottom of cylinder bores, stronger/more reliable ? Casey, just think, if you use a 300 block, you can install a 340/350 Buick crank and have 3.8" of stroke ! I'm getting a quote, from a local auto machine shop, to install my flanged liners,(Wildcat) with "sleeve retainer compound". IF this works well, it will get a hyd. roller cam,( I know a guy with a LOT of blanks and lifters). Logical choice for heads is Merlin or TA.

Will the 3.85" crank fit the Rover block and clear the pan rails? Seems that might be a problem.

Jim



Edited 1 time(s). Last edit at 12/12/2016 02:30PM by BlownMGB-V8.

Art is referring to the 340/350 crank in the 300 block. Actually 3.85 stroke.

It looks like if I do go with the 300, it would make sense to find a 340 crank. If I go with the extra weight I may as well squeeze the extra displacement out of it. Hmmm...

"Will the 3.85" crank fit the Rover block and clear the pan rails?

Jim"

Yes.

Greg

With the rods on it I presume?

Some clearancing required:

[forum.britishv8.org]

Using a front cover with the integral pickup is helpful. The crankcase oil pickup inlet has to have some meat ground off otherwise. Also two spots inside the crankcase have to be ground away beneath the front and rear cylinder. Otherwise, looks like it can be made to fit cleanly.

Greg

Greg, About time you got on here!

It would need either a pan spacer or a modified pan of course.

Jim

Check out the Aluminum V8 web site for some information and ideas.

I wonder if the P76 crank will fit a 4.6 block. The main journal diameter might be too small. You can use an earlier 3.9 block.

I would guess that the P76 crank has 2" rod journals. Your choice of rods includes the stock 215 rods, Chevy 327 rods, and Buick 300 rods. Rover 3.5, 3.9, and likely the 4.2 rods will probably fit up, too. I use the Keith Black/Silvolite catalog when I'm browsing for pistons for a stroker lash-up. Of course, you'll have to do the math to calculate compression height to search for a piston.

The Buick 300 heads are about right for what you're doing. The 215 intake is a low-profile design and is usually used in swaps.

Good luck.

Paul

Thanks for the info Paul, I will have to decide which way I want to go. I would still like to answer the initial question--so lets say I end up with $900 in the aforementioned parts, then $1100 in liners via this guy's method (http://www.landroversonly.com/forums/f40/my-diy-cylinder-liner-sleeve-removal-top-hat-install-video-pics-inside-68210/). Is $3k enough to get the rest done? Going with a 300 or other crank would lower the parts and machining cost, so that would probably need to be done away with (if my math is correct you would lose 12ci, but I think the increase in RPM would likely make up for it).

The 300 crank needs a seal adapter to fit it to the 4.0/4.6 block and a custom flywheel. An alternative is a 4.6 crank offset ground from 3.22" to 3.375", but you'll have to find a machine shop that can do the work. My point is that you might ask around to see if there's reliable shop to do the offset grind. It simplifies the job to use the original type crankshaft.

4.6 stock 3.22" stroke is 277 ci.
The 3.375" offset stroke is 290 ci.
The Buick 300 3.4" stroke is 292.5 ci.
A P76 3.5" stroke in a 3.9 block is 301 ci.
4.0/4.6 w/340 3.85" crank is 331 ci.
Buick 300 w/340 3.85" crank is 340 ci.

If you can get the P76 crank, look for a 3.9/4.2 block. That seems like the best combination. The 300 heads have bigger chambers to help keep the compression ratio reasonable.

I favor using the 4.6 crank in the 4.6 block. I'll consider pricing the offset grind of the 4.6 for my projects, but if I really want more, I'm going with a stroked Buick 300 (stroked to 340). Transmission fitment is easier on the Buick 300 block - stock manual bellhousing fits a T-5, and the 200R4 automatic 4 speed with overdrive is a compact, strong transmission with a good first gear ratio.

Yes, $3k is more than enough to get the rest done.

Fun!

Update, added the 4.0/4.6 with 340 crank combo. I'd forgotten that this has been done with a 3.5 block. Seems like a good combination for the kind of daily driver that some of us would like. Since I have a 4.0 and a 340 crank, this might be the eventual build I go with.



Edited 3 time(s). Last edit at 12/13/2016 04:36PM by pcmenten.

The 4.2 blocks are not given good marks by Glenn Towery, Woody Cooper, & Justin Broome.

Just wanted to add that it is not clear if this is with the original 2 bolt main block or the later "interim" block that had the capability to be turned into a 4 bolt main block.



Edited 1 time(s). Last edit at 12/13/2016 10:01AM by MGBV8.

I left a message with the man who owns the engine asking to know what he wants for the complete motor and swapping the 2 barrel intake for the 4. I figure then I can have my options open for either a Rover build or a 300 based build. My question is, how many cubic inches do the ported 300 heads support? I don't want to go trough the trouble of maximizing displacement if the heads won't breathe sufficiently anyway (and TA heads plus porting are not in the budget...).

Casey, The 300 head was THE head before the T/A head came out. Larger valves and seats are the key. 2.3 Ford 1.74 IN and 1.5 EX are what I used years ago. 305 Chevy are the same with taller stems. Ported have gone 200 IN and 150 EX which should be good to 400HP. I would use studs or steel thread inserts in rocker hold downs.

We need to dig up the thread where Dan Jones has the flow numbers for ported 300 aluminum heads.

I have found the thread you speak of and contacted the same company he used (JDC Engineering) to get a quote on porting. The 340 crank mains are 3 inches correct? Would it be possible to offset grind them for a gain of say, .4 inches, for a total stroke of 4.25? Of course you would have to find a rod to compensate but that would yield 375ci with a stock bore or 385ci going .050 over. Just an idea.

Hi Casey, Grinding the mains will not provide an opportunity to offset grind the rods journals. As it is, the 340 crank is already about the biggest you can fit into a Rover block. Some grinding will be needed to make it fit.

I had forgotten that the 340 crank can be fitted to the Rover block and I'm thinking that's my next engine project.

Other recent projects;

351 'Clevor' stroked to 393 for a 70 Mustang
224 Studebaker bored and stroked to 308 in a 1952 R1 pickup truck

Potential new projects;
Ford 2.8 V6 stroked to 3.5 for a Sunbeam Alpine
Rover 4.0 stroked to 5.4 for an MGB

Ha! Well that's my moment for the day... Sometimes the hands type faster than the mind thinks. I am interested to see how the 340 crank in the Rover block would work though.