Engine and Transmission Tech

Good points, Art. About your earlier comment, are they really improved & are they still available?

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Do we understand that "Coscast", new and improved, RV8 blocks are available ?

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Anyone who may be considering a Coscast block may want to reconsider. A friend just contacted V8 Developments and got an interesting response from Ray Webb: We can no longer supply Costcast blocks or short motors. Coscast blocks do not address the problems associated with Rover blocks ie slipping liners and porosity.

So there we are, the end is near ! Only prox. 1.7m used blocks left... "This Rover died of stroke"

Pics of Huffaker intake on spacers for 300. Not mine, but gives an idea what it looks like. Probably 3/8" for spacers and 1/4" for valley cover.

"Of all the engines to work on, the 300 with the 340 crank has the most appeal. With aluminum heads, it makes for a simple, lightweight engine that bolts up easily and cheaply to a T-5 or a 200R4 transmission. It is compact and reliable. Even with stock parts, such as 340 exhaust manifolds and 64 aluminum heads, it would be a strong performer. "

391 HP at 5700 RPM and 422 ft-lbs at 3700 RPM, per the article. Not too shabby.

I think personally, Chris Gill's version is better. Stock longer 350 capscrew rods and lighter pistons. He had some bad luck and on hindsight I would recommend the Fitech TBI over the Megasquirt. He is retarding the cam to move the RPM range up. We would have beat the Hot Rod mag version with a hotter cam. Carl, You may get a deal on his aluminum flywheel as he is going back to iron.

Too light for him? Thanks for those spacer pics!

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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.



Edited 1 time(s). Last edit at 02/07/2022 04:22PM by MGBV8.

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

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.

Very nice Chris,

that engine bay is something to be proud of!

Live like you mean it.
fred

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.




Edited 2 time(s). Last edit at 12/09/2016 07:23PM by mgb260.

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






Edited 1 time(s). Last edit at 12/09/2016 07:08PM by MGBV8.

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.



Edited 1 time(s). Last edit at 12/09/2016 07:21PM by mgb260.

It also appears to be bigger than 3.8"

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

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

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

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

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

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.