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tips, technology, tools and techniques related to vehicle driveline components

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BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 21, 2009 09:07AM

Better finish that engine Nic!

The BOP/R has the center lobes splayed a bit to clear the siamesed center ports, where the 350 has the front and rear runners paired. The center offset is close to 3/8" at the cam so you probably couldn't run a 340 cam in a 350 even with oversized bearings. That is part of what we are trying right now to figure out. Undoubtedly a custom cam, he mentioned that the lobes were well centered under the lifter bores. Possibly it will have some markings on it that can be used to identify the source.

Jim


pcmenten
Paul Menten

(242 posts)

Registered:
10/08/2009 10:40AM

Main British Car:


Re: TA Performance heads for the BOPR and SBB
Posted by: pcmenten
Date: October 22, 2009 11:42AM

Seems to me the hot ticket would be the 300 block with the 340/350 crank.

If the 340/350 is a taller deck version of the 300, there ought to be a way of doing it.


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: TA Performance heads for the BOPR and SBB
Posted by: roverman
Date: October 22, 2009 02:45PM

Paul, I "think" the 340/350 has monster 3" mains? 300 has 2.5". Your thoughts on this? Anybody? 340/350 block being both taller and wider than 300, fitment issues in likes of MGB's etc.? Old School method in strength to effort ratio was using 427" Ford main bearings,2.75" dia. Using a #8620 or #9310(better) material for "roller" cam, is strong enough to get the base circle small enough to clear the 3.85" stroke. Giving-up some lobe lift to clear, you can get back with rocker ratios. Monster torque or high rpm. HP.? Can't have both with this set-up. roverman.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 22, 2009 05:15PM

You could do that, if you were willing to go with custom pistons and move the pin up so that you could keep a favorable rod ratio. Also have to cut the mains down as Art mentioned. Now that I think about it, the cam is no more of an issue than it would be in the 340 or 350 block, since all of these engines use the same timing set. The smaller stroke engines do indeed have more cam clearance, something I may have mis-stated.

Anyway, the extra width is not an issue, but the extra height might have to be dealt with, depending on your choice of induction system. It may be as much as 1-1/2" taller than the 215. (Which, with the stock intake was a short engine to begin with.)

Jim


pcmenten
Paul Menten

(242 posts)

Registered:
10/08/2009 10:40AM

Main British Car:


Re: TA Performance heads for the BOPR and SBB
Posted by: pcmenten
Date: October 22, 2009 07:27PM

Art, that's good information. Yeah, my first thoughts would be to turn the mains down, losing the rod/main overlap.

It's pretty much idle talk from me. I do have a 340/350 crank kit, but no intention of doing anything with it besides selling it. But for a MGB application, it might be a fun option partly because it allows the use of an automatic transmission with a BOP pattern, something like the 200R4.

But Jim is right about the incremental issues like hood clearance.

BTW, are roller cams ever used in these Buick/Rover engines? I didn't see anything with I did a quick search with google.


hoffbug
Tony Hoffer
Minnesota
(323 posts)

Registered:
10/15/2007 05:25PM

Main British Car:
Olds 215 EFI

Re: TA Performance heads for the BOPR and SBB
Posted by: hoffbug
Date: October 22, 2009 09:17PM



pcmenten
Paul Menten

(242 posts)

Registered:
10/08/2009 10:40AM

Main British Car:


Re: TA Performance heads for the BOPR and SBB
Posted by: pcmenten
Date: October 22, 2009 11:52PM

Ah ha! I had read that, but I had read so much stuff recently, I couldn't remember it clearly. It would be interesting to hear what Dave Michel did with the engine.

348 cubic inches. Reading Blackwood's description of his work, I find a reference to block weights that says the 340 block weighs 82 pounds more than a 215 block. I'll guess that the 300 block weighs about 55 pounds more than a 215 block.

Hmm. I have the chance to weigh the 340 crank and the 215 crank. I'll do that soon.

That would put the stroked 300 with T5 maybe 50 pounds more than the original 1800 w/OD?



castlesid
Kevin Jackson
Sidcup UK
(361 posts)

Registered:
11/18/2007 10:38AM

Main British Car:
1975 MGB GT Rover V8 4.35L

Re: TA Performance heads for the BOPR and SBB
Posted by: castlesid
Date: October 23, 2009 06:42AM

You guys have got me going again, must dash out and buy some more lottery tickets!

That combination would make some serious power without having to worry about the inherent fragility of the Rover block.

Curious to know how you would overcome the alignment problem of using the 350 block with it's different cam lobe and presumably lifter bore spacing with either the 215/340/Rover/ TA head pattern if you used a cam to match the TA heads arn't the lifter bores going to be in the wrong position?

Also what is the advantage of using the 350 block as opposed to the 340?

I love thinking out of the box and this has wetted my appetite, now thinking well built 350 bottom end TA heads, decent induction system, Meagasquirt ECU and a 250 shot of gas should make for a 600-650 BHP motor, now that would give my friend Perry something to think about, he's the guy with the extremely rapid 4.6 engined MGB GT now doing regular quarters at 10.66 at 126MPH and looking to get it down to minus 10 seconds, I'm just dreaming but who knows,

Kevin.


NixVegaGT
Nicolas Wiederhold
Minneapolis, MN
(659 posts)

Registered:
10/16/2007 05:30AM

Main British Car:
'73 Vega GT 4.9L Rover/Buick Stroker

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: NixVegaGT
Date: October 23, 2009 08:44AM

Jim's point about the 350 block is that its WAY more plentiful than the 340. Ok so here's a conundrum I've always been confused about. Why does the 300 weigh more than the 350?

I've seen a number of references that show the 300 at 462 lbs. and the 350 at 450 lbs. If the stat Paul laid out above is right then the 340 must be 489 lbs. I know the '64 300 heads are about 17 lbs each. so that means the '64 300 should be about 407 lbs. The references I've seen put the 300 weight at 400 lbs. so was the '64 using an aluminum intake? The weight savings for the 350 can't be just in the heads and intake, it's got to be in the block too, right? There's some savings in the intake because of the shared runners compared to the 340 but it's gotta come up with 39 lbs. from somewhere. Anybody got a 350 block handy to weigh? I bet it comes pretty close to the 55 lb mark of the 300.

The Lord's light shine on Buick for being so fixated on engine weight. The lightest, torquiest 455 and the lightest all iron 350. Lightest by a LONG shot.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 23, 2009 10:09AM

Some weights for you guys to ponder, based on actually placing the parts on the scale. The 215 block weighs right at 60lbs. The 340 block is exactly 82 lbs heavier than the 215, so 142 lbs. The '64 300 engine is 80 lbs heavier than the 215 exactly (according to Mike Moore). Piston weights are very similar, rods likewise, we're talking grams here. Cranks typically weigh in around 50 or 60 lbs and are very similar also and I may have an exact weight around here somewhere, I can weigh a 215 crank if you like but there isn't much to be gained there. Bear in mind the change in main bearing size from 300 to 340/350 matches an increase in hole size in the block.

The light weight of these engines is due to pioneering work that Buick was doing on thinwall castings during that time period, and they continued to refine their skills as they developed the 350 and the 455 engines. As a result, these were some of the lightest iron engines ever built in terms of weight/displacement. In the case of the 455 they pushed it far enough in the early 70's that over the next few years they felt they had to add weight back in for critical areas and the mid 70's 455's are therefore a bit heavier. This was not the case with the 350 however and to the best of my knowledge it remained the same weight during the entire production run. Developed progressively up through the displacements, by the time they derived the 350 from the 340 they had it pretty well dialed in.

As the lightest iron V8 in the line, the 350 is the obvious choice when combined with aluminum heads and intake, bringing it within spitting distance of the original B series engine weight. It also had the greatest production numbers, well into the tens of millions if I remember correctly, where the 340 numbered maybe 3/4M at best over two years of production and the 300 wasn't that much higher. The actual numbers are in a thread on the V8Buick site so if I get a chance I'll look for them. The iron block is quite strong, having stood up to power output levels of 1000hp without problems like block flex or thread pull-out that plague it's aluminum brethren. The more modern bellhousing pattern is also a plus.

From one owner who claims to have a 350 block with 340 heads, pushrod interference is a non-issue, though the pushrods do appear canted slightly. Tip wear is even. Since the guide holes in the heads are only about a quarter of the way down the pushrod, the effect of the lobe offset seems to be fairly minor.

A 215/300/340/R cam CANNOT be used in this engine without extreme efforts. The journal sizes do not match and the lobes have different spacing, off by perhaps as much as 3/8" at the center lobes. (I don't think this has been verified by actual inspection though, and cam bearing spacers are an option) Therefore, a custom cam is the most likely solution. We are waiting on Randy to respond with more information about this mystery engine, hopefully he can find some cam markings which might help us to identify the source of the cam in his engine. If so, we may find a source for the correct cam blanks.

However, TA has contracted a limited run of 350 roller cams which have shipped to the customers. Somewhat expensive as they were billet items, the original intent was to have them made with a firing order swap (5&7 I believe) for a more performance oriented configuration. The actual parts manufactured came with the standard firing order due to a miscommunication, but this just illustrates that for equal money any lobe pattern (BOP/R for example) could be used.

So at this point it's just money. But it's not that far out of line for a light strong badass of an engine. Heck, if you powder coat the block silver very few will even know it isn't a Rover!

Jim


castlesid
Kevin Jackson
Sidcup UK
(361 posts)

Registered:
11/18/2007 10:38AM

Main British Car:
1975 MGB GT Rover V8 4.35L

Re: TA Performance heads for the BOPR and SBB
Posted by: castlesid
Date: October 23, 2009 12:45PM

If the lifter bores for the centre two ports are 3/8th off line for the 215/300/340/Rover heads would this not put a lot of side thrust on the lifter bores and valve gear?

Kevin.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 23, 2009 04:03PM

Not that much. That's about 3/8 in 12 or more inches or a ratio of about 30:1 or greater so for 300 lbs of lift pressure you'd get 10 lbs or less of side pressure. The valve train can easily handle that, provided the lifter isn't spring loaded in that direction. If it is, solid spacers instead of springs would solve the problem.

Jim


pcmenten
Paul Menten

(242 posts)

Registered:
10/08/2009 10:40AM

Main British Car:


Re: TA Performance heads for the BOPR and SBB
Posted by: pcmenten
Date: October 23, 2009 04:33PM

Regarding canted pushrods, my Olds heads have offset rockers. I wonder if they'd help cure the canted pushrod problem.

Re; 300 vs 350, I'll have to do a search, but I think the 350 block is taller, and that might be a deal breaker in an MGB. But the weight of the 350 block being the same as a 300 is pretty impressive.


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: TA Performance heads for the BOPR and SBB
Posted by: roverman
Date: October 24, 2009 01:21PM

It would be great with these, out-there, engine builds to see a price tag, maybe dyno results? Just for me, I would turn down the counterweights vs. cutting down the pistons underneath. With lighter pistons/rods vs., oem.,one might not need that much heavy metal to balance. Has anyone out there run "deck plates" on a BOR. with the new sleeves through it all ? Other than the core shift issues, I don't see the late Rover block as all that fragile.roverman


NixVegaGT
Nicolas Wiederhold
Minneapolis, MN
(659 posts)

Registered:
10/16/2007 05:30AM

Main British Car:
'73 Vega GT 4.9L Rover/Buick Stroker

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: NixVegaGT
Date: October 24, 2009 04:59PM

I suppose you could destroke a touch to get it to fit a late Rover block. Do they make OS journal bearings up to like 50 thou or something? Maybe it would be possible to destroke a 350 crank to 3.75" and use the SBC 5.7" rod with a custom 10 over 305 piston.

Then again that's a lot of work and money for only 50 lbs weight savings. It would be a dimensionally smaller engine though. Smaller cid too: 330. The rod ratio would totally suck though.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 24, 2009 08:23PM

See that's where you need to take advantage of the low pin position on the Buick pistons and move the pin up to get a better rod ratio. You still run into the problem of interference between the crank counterweights and the piston skirts though and I don't know how severe that would be with a 3.85 stroke in a Rover block. Maybe custom forged pistons would solve it, maybe you would need to cut the counter weights as Art suggested. But his point that with lighter rods and pistons the weights could be reduced is a good one and it might be worth talking to an engine balancer about. After all, any decent sized lathe could handle that job easily. Personally I'd rather have the iron block, and building a 350 by using a 300 block is certainly feasible if deck height is a real concern.

But as far as build cost goes, I have probably around $1500 in my reciprocating assembly and that's with Venolia forgings and 7" Scat rods. The other costs have been largely comparable to any standard rebuild except for a few things like o-ringing the deck. So while I can't give you a total, I'm quite comfortable in saying that I could duplicate the engine for under 3 grand, not including induction or assembly costs.

Now if I was starting over with a 350 short block and putting nominal costs at about $1500, plus the TA heads for about 2 grand, plus a custom roller cam and lifters at around another grand, plus an intake at about five hundred, that might get us in the ballpark of what such an engine would cost to build. So for around 5 grand or so, a pretty hot engine that doesn't need zink additives in the oil and can run about as hard as most guys are willing to push it. That's not too bad, and really, no custom machine work and the short block is bone stock or close to it so it's a cheap and easy replacement if needed. The heads can be rebuilt indefinitely. That's not such a bad deal. Horsepower of such an engine would be a very flexible thing, depending on cam choice, etc. but over 300 would be the baseline with a stock cam and it would go up significantly from there.

Jim


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: TA Performance heads for the BOPR and SBB
Posted by: roverman
Date: October 25, 2009 02:25PM

If I just had a P-76 block, I could commit to a 32 valve with 3.85" stroke. No "bump" issues on the cam, there all upstairs in the Lotus heads. Reworked heads with bigger valves reported to flow 305 @28" and .450" lifts.In other words, these heads would adequately support the inches. Jim, did you say "7" rod? Compression distance on your piston? Go with the flow, in a good way, roverman.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 25, 2009 05:35PM

Yep, 7" C-C. They are FHF rods so they use the Buick bearing inserts and have a 3/4" piston pin. That's a mite small perhaps and the pins I ended up with are thin wall. But very light. That's the one place in the engine I feel might be a little weak, but what's done is done. The pistons have a 1.283" compression height so with a 10.208" deck, 20cc dish and 52cc chambers the compression came out to 10.6:1. The pistons are actually a bit proud of the deck, maybe .008" depending on rock and .050" head gaskets.

But the compression height on regular Buick pistons is closer to 1-7/8". Depending on your ring package you could easily get down to 1-1/4" so that's 5/8" you have to play with on rod length and stroke, maybe more.

Jim


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Performance heads for the BOPR and SBB
Posted by: BlownMGB-V8
Date: October 26, 2009 11:27AM

I just got word that TA is halfway finished with the programming and setup to machine the 4 sets of new head castings. Based on that I'd say they will be ready to ship by about Thanksgiving. At last check there was one set out of the three that wasn't spoken for. Price is going to be in the 2000-2500 range and those who have seen the heads on the MGB-Roadmaster 455 will recognize that these are quality pieces. This is actually a rare opportunity and I wouldn't be surprised if the 4th set aren't already spoken for, but I'd like to see one of my peers get them if possible. How many sets are made will depend entirely on how well they sell. If these first four sets go out the door right away they will order up some more immediately. If not, no more will be made until the last set sells, and maybe not until another set after that is ordered. You see how this works? A small volume producer can't afford to tie up a lot of assets in inventory. So if you're on the fence, calling them up to see if you can get that last set does two things. It either gets you a piece of a very exclusive production run, and if not that at least gets you in at the beginning (They are probably numbering them and the other sets are going to Australia), and it insures that at least one more set of castings will be run. Both good things for you and the rest of us. I'd do it myself if I could.

Jim



Edited 1 time(s). Last edit at 10/26/2009 01:16PM by BlownMGB-V8.


Greg55_99
Greg Williams

(101 posts)

Registered:
11/01/2007 07:12PM

Main British Car:


Re: TA Performance heads for the BOPR and SBB
Posted by: Greg55_99
Date: October 26, 2009 01:19PM

P76 block with a Buick 3.85" stroke crank...

Yeah, I've seen one of those.... Be nice with a set of those TA heads and a 3.75" bore...

Greg
350_crank_7.jpg
350_crank_5.jpg
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