Buick 300/350 stroker thread

[MGBV8]

Too light for him?  Thanks for those spacer pics!

[MGBV8]

What would you do if your motor blew up tomorrow? Just curious.

The quick engine reload, Scott, would likely be to put new rings & bearings in one of my 3.9 engines reusing the stock pistons & slap on the late 4.0/4.6 heads. I have an adapter ring from Dan Lagrou that will allow me to use the mini starter from my Buick 215. I also have a Crower 50232 cam & lifters, two more 4bbl intakes (one is an Edelbrock), plus a NASCAR Holley 390 carb.

I could get back on the street fairly quick, then go back to pondering about my ideal engine choice.

[cgill]

Great thread guys, and thank you for the kind words about my car. But the praise really should belong to a bunch of people including Jim N., Jim B., Curtis, etc.

Yes, I had some issues along the way but they were really just the typical stuff you encounter when fitting a square peg in a round hole. I should have pressure tested the block before doing all the work. Then I would have found the hairline crack. But it's fixed now so all is good. Sometimes I just needed to rant to make me feel better.

As for the EFI, I would have probably gone for a throttle body EFI in hindsight but I'm not sure it would have fit under the RV8 hood. The Megasquirt EFI works but I'm personally not super psyched on it.

I'm running 225/50/15 tires on the car. With the slightly wider engine block, I was getting some tire rub with my RV8 headers. So we shortened them about 3/4" and I installed 1/4" spacers. All is good now, but I'm installing the Saturn Vue electric power steering box to make slow speed driving more enjoyable.

The engine is out right now because I'm installing a heavier flywheel. The 10lb aluminum one was great for throttle response, but it made me look like a new driver every time I had to pull away from a stop sign (lurching or over revving to get going - it drove me nuts!).

I'm also retarding the cam, like Jim N. mentioned to get a bit more performance out of the engine. But overall I'm really happy with how it turned out. It needs a bit more fine tuning for the idle but aside from that it's good to go.

I went for a more streetable cam than the Hot Rod Magazine build because I wanted a driver. The car is very tame to drive on the highway (cruising at 2000 RPM at around 60 mph) but is completely nuts when you put your foot into it (second gear burnouts without the clutch are almost too easy).

Best,
Chris

[cgill]

I'm also happy with how the engine looks aesthetically.



I had a spare 300 block but didn't want to get rid of it so I decided to turn it into a coffee table for the time being.

[DiDueColpi]

Very nice Chris,

that engine bay is something to be proud of!

Live like you mean it.
fred

[mgb260]

Carl, If you go 300 Destroker like Derek suggested with the 6.45 NASCAR rods. I found the perfect piston in the Silvolite catalog. 3159HC 96-04 Ford 232 V6. 1.43 comp. ht., Coated, Hyper, floating pin for bushed rod. You don't need the cost or strength of forged unless boosted or raced.

[MGBV8]

That is sooo much sexier than a stock Rover soup can piston!

[mgb260]

There may be a problem with the rod not having enough meat in the small end to bore for the Ford pin. I guess you could bush the piston for the smaller NASCAR pin. This idea was for the 300 crank offset ground to the Honda rod size for 3.31 stroke.

[MGBV8]

It also appears to be bigger than 3.8"

[mgb260]

Carl, Yeah. 3.81 is .010 over. .060 over 3.75, 300 size. There are some 3.78 pistons,  .030 over.

[MGBV8]

I guess that is about the limit for a 300 block.

[mgb260]

Carl, Chris went .050 on his build. Used 3.78 +.020 for stock 350 bore of 3.8.

[BlownMGB-V8]

I went 0.050" over also for 350 cid on the 340 block. I had one wall that ended up about 0.110" thick, it was not a thrust wall. So I could have gone bigger, but thicker walls make for less flex and a more reliable engine. Plus it could be rebored once if necessary. In my case it was a reman short block that had been poorly done and we corrected the flaws by increasing the bore a bit.

Derek seems to think the 300 has thicker cylinder walls. That may or may not be true. The 300 and 340 blocks weigh the same despite the difference in deck height so the extra metal had to go somewhere. The bores are the obvious place so there could be something in that. Or, by the time they did the 340, Buick had found other places to remove metal. Also likely. A sonic test is the way to find out for sure. If I were building one I would get the block and test it as the very first step. The first one might not be the one you end up building. Luckily, rebuildable Buick 300 cores are cheap. Then I would pressure test, have the bores straightened out, then buy the pistons, then hone to final size, deck and align bore. By that point you don't have a tremendous amount of money in the engine but you know that what you have is good. So you can move on to crank, rods, heads and valvetrain.

Jim

[BlownMGB-V8]

One good thing that came of this discussion, over on the Buick board, is that the early Buick 350 rods are 100 grams lighter than the late capscrew rods. The reason this is important is because with lighter rods and pistons the engine will rev quicker, which is more in keeping with our usage. The early rods are fine for a 400+hp build which is more than most of us are looking for.

Another possibility might be to ream the pin bores of the Courier pistons to the Buick size, eliminating the need to bush the rods. But clearly if we could find a similar piston with the right pin bore it would be better.

Jim

[mgb260]

Jim B., The lighter earlier rods can be fitted with SBC ARP rod bolts also. The bolt heads will have to be ground for cam clearance like in the Hot Rod mag build. Maybe the threaded ends also in the shallow pan area. I would magnaflux check, sand the sides and shot peen. The reason most prefer the capscrew rods is they are good to about 600 HP and have more clearance. The pistons used were Ford Ranger 2.5 SOHC standard size of 3.78 +.020. There appears to be lots of material to ream the piston bores or bush the rod for floating pin. Chris was limited by budget compromises on valve size also. The valves I recommended, 1.72 intake and 1.42 exhaust required new seats. They were turned down to 1.69 and 1.39 which is max for the stock seats. The cam will be much better retarded 4 degrees. He has more torque off idle now than the 215 had total.

[MGBV8]

I agree with retarding the cam.  The LBC doesn't need all that stump pulling torque.  Move it up the rpm range & stand on it.  

[BlownMGB-V8]

Ditto.

Would need pin locks for floating pistons, a further complication. Buttons don't work with slipper style. Anybody have experience with reaming piston pin bores? I don't. But that seems to me like a good solution. Is it a 0.040" increase in bore diameter Jim?

I think this is a good alternative to building a big Rover as the expense of the top hats and bellhousing/flywheel could be used to buy TA Rover bare heads. I just made the call. Bare heads with seats and guides are $1500. If you want CNC porting, Mike handles that through a 3rd party and the cost is $1000. According to Sandy that would be a maximum porting effort as there would be no other reason to do it. So add the cost of a standard valve job with upgraded springs and new valves and you are there. Brand new ported TA heads for the extra cost of building a Rover. Not a bad trade I think. You still need to sort out your intake manifold but as we've seen that challenge is not so great. Then there is the extra height and width but again, doable. Can anybody confirm that the late Rover is 30 lbs heavier than the 215? That seems like a lot to me. It would mean the block is 90 lbs instead of 60, or 50% heavier. It's hard to see where the extra metal is. But if true it would mean only a 50 lb penalty, for which you get quite a lot.

Jim

[mgb260]

Buick 300/340/350 V8 piston pin is .940, Ford is .912. .028 difference. The weight of the Rover block probably increased slightly with the crossbolted block and engine weight went up again with the larger journal crank.

[pcmenten]

Regarding the extra weight of the Rover engine. I think that two sources of the extra weight are the larger journal diameters on the crankshaft as well as the longer connecting rods. I wonder if the flywheel and balancer are also sources of the extra weight. Then there's the EFI intake.

[BlownMGB-V8]

Yeah but that surely wouldn't account for 30 lbs. The 215, 300, and 340 cranks all are within a pound or two of each other. That's not to say the Rover crank isn't heavier, but until we know it remains uncertain.

Jim

[Moderator]

<a href="http://forum.britishv8.org/read.php?6,2351">Here are accurate weights of Rover 4.0 and Buick 215 blocks (with main bearing caps, etc.).</a>   (Note: there shouldn't be a significant weight difference between a 4.0 block and a 4.6 block.)

[BlownMGB-V8]

So that is interesting. And I'm not saying your numbers are off, but I have shipped a couple of 215 blocks with a 60 lb weight limit so I'm just saying there is a weight discrepancy somewhere. I got the following weights:

215 block with cam bearings, main caps and bolts:  60 lbs
300                                                                      : 140 lbs
340                                                                      : 142 lbs
216 crank                                                             :  60 lbs
The 300 and 340 cranks were within a pound or two of being the same

It's been quite awhile since I weighed these but the numbers shouldn't have changed. Unfortunately I no longer have the parts so I'm not able to double check. I noticed Glen was thinking " sixty few pounds" Anybody else? Is it possible that "215" block could have been a Rover 3.5L? That could account for the difference.

If so, 16 lbs difference in the blocks, 3 in the heads, another lb here and there, it *might* be possible to add it all up to a 30 lb difference. I don't know. I guess it wouldn't be that much of a stretch.

Jim

[Moderator]

No.

Putting the iron caps in a separate box would have given you and Glen the number you remember.

[BlownMGB-V8]

Doesn't seem right Curtis, but it's been awhile. I believe caps and bolts were 8 lbs. I'm pretty sure I posted the weights and conditions on this forum though so it should be possible to find them, though maybe time consuming.

Jim

[BlownMGB-V8]

The more I think about it, the more you might be right. There's no way I'll ever find the original post where I gave the weights that I had gotten, I know there was once a way to do a custom search but that seems to be gone, there's no way to access the posts or threads I started, so it's hopeless. Too bad. It might have supported what you say. After all, 68 lbs or so would just allow enough for a cardboard box with a shipping weight limit of 70lbs and that might have been it.

Jim