A guide to building the lil guy. The Mighty 300

Yeah, some people can't see through the sticker shock of the Piston AND ring set that is the sbb AutoTec pistons are sold as, so I try to shed a little light on that fact.

With a HP goal of only 300 HP cast pistons would be MORE than good enough or hypers for that fact. Whatever will work for that level will be more than good enough even @ the 450 HP level! Maybe not so much for the probably unrealistic RPM level for the low HP level though with that many cubes?(unless the compression is 6:1)

The cast piston post was a question not a remark. I know the 4032 forged material will handle the RPM, but never considered a cast or hyper to spin that fast, can it handle that at the wanted HP level?

At that level the cam needed wouldn't have to be to radical, a hydraulic flat tappet cam would be good enough, even the more radical ones are limited to a max RPM of 6,500 if the intake can keep up?(because of hydraulic lifter limitations) So why the flock not hypers or cast pistons?

I have to call BS Jim, you don't build anything "just good enough", it just doesn't add up and why would you even say you want to use TA Rover heads to get 300 HP? LOL What are you really planning?

 

Well to start with there's the 6500rpm myth about hydraulic lifters. That's a specification and we all know how they relate to the real world. If you've never used stiffer springs to get another 500rpm out of them then you have my sympathy. I have and it does work. Not to say solids wouldn't be better at that speed but you can't call BS on that one.

Hey, maybe the hypers would be OK. But maybe not, and I don't care to break more pistons finding out. Been down that road before. So if I build this engine, forged it's gonna be. And if it's a $200 difference between screwing around with forcing something to work and calling up Venolia and placing another order, that's not such a hard decision. Amortized over the life of the engine that is chicken feed. Subtract a few hundred from the cost of the rods and it's a wash (because then I can use any rods I want with them). Looks like that may still be the only really feasible option, especially when you start considering piston dish, squish, pin size, lock type, and all the other little details that go into it. There are a lot more details to a piston than just bore size.

The intake is a fixed spec, a little wiggle room in the heads, exhaust, and fueling, which leaves the cam. Whatever the horsepower turns out to be will be a factor of all these elements and I'll say it yet again, I am NOT building to a horsepower specification. I have the luxury of allowing that to be one of the lesser considerations. Yes, it would be nice if when all is said and done the output is "over 9000". But the minimum target is 300. Sorry you don't like that, but it is enough for exceptional performance in this package and anything more is just a bonus. And I LIKE bonuses.

Jim

 

And another thing, what is the deal with these big humongous wrist pins anyway? We go to all this effort and trouble to take 20 grams off the rod or the piston and then slap in a big honkin' 1" wrist pin that weighs 250 grams? When one that weighs 70 would work just fine? I just don't get that.

 

Flex and lifespan on the pins/pistons, but there definitely is some middle ground.
Some of that incredible weight savings is due to the shorter pin used with the newer design pistons.
That was one of the bene's I was looking for with OEM replacement imports and their design advancements being similar to race stuff.

Cast, hyper and rpm?
I don't think every high rpm import uses all forged slugs.
I bet it's more of a design thing.
OUR old slipper skirts with the oil return slots almost across the entire skirt is the weak part, right?
Soo many CT engines wind up pretty high and aren't tuned the best with hypers.
The failures are usually operator error, neglect, or simply life span issues.
Completely agree with the concept of amortizing unavoidable costs and balancing those with savings elsewhere.

 

I'm just saying with a stroked 300 to 350 cubes you can hit your HP goal with stock 300 rods with the Olds hyper pistons like the HR magazine build used without having to spin the thing to 7, it would only need to spin to 5,500. You can even hit that 300 HP number with un-ported '64 300 heads and intake. It would probably make 300 HP @ 5,200 and 400 ft lbs @ 2,800 depending on cam. Why even mess with the nascar take outs with that small of a HP goal? No need for forged pistons either with that low of an RPM needed to make 300 HP without even trying.

Hell, why even use a sbb 350 crank for that HP goal when the 300 crank would be more than enough to get to 300 HP? You're just dragging the power band down with the extra cubes. If you want to run the nascar rods, just stroke the 300 crank from 3.400" to 3.540" and use 6.450" rods and still have plenty of rod to cam clearance with a 321 cid engine(3.800" bore with the 3.540" stroke).

Don't build a 300/350 just so you can say you did it when that's not what you need, a 321 stroker would be just as cool if not cooler because the power band would be higher like you want with the fewer cubes to get to the same power as a larger cid engine would have to rev to. Plus with the smaller cubes the low end torque would be slightly reduced to a more street friendly level. Don't get me wrong, the 321 will still make a boat load of low end torque to propel what was it 2,800 lbs? Much much more than a puny 215 would ever think about making.

The plus plus plus would be the $$$$ savings doing the 321 vs the 350. You won't have to source the 350 crank and then have the expensive grinding done to the mains and the rods cut down to the take out size. The 300 crank may be good enough to polish the mains and just have to have the stroke altered cut down to 1.850". I would recommend heat treating the crank with either one you choose to do but not absolutely needed.

I guess I just don't get it? GL Maybe what I wrote will help someone else looking at a sbb 300 build?

 

You're cracking me up Derek!

How many times do I have to say I'm not building it to a specific horsepower goal? I realize you just don't get that. I do like power and will take any I get, but what I want out of the engine is: A 7000 rpm redline and, a decent idle. The engine I am running in my '71 is 350 cid with a hot cam and 5-6lbs of boost and I'm pretty happy with the power level, but the other car might be as much as 600 lbs lighter so that should be fun. I could probably do that with a stock cam and stiffer valve springs but the TA heads would support the top end a lot better. Now, do I need 300cfm? No. So there's no real need to port them. How much do they flow unported? I don't recall but I'm pretty sure it's better than unported 300 heads. I'll be sure to ask Dan before I spring for them. So for the cost of a bare set of heads, that's something feasible that should make a noticeable improvement. Don't rag on me for not springing for the CNC porting job, it's not a drag engine and I don't have to have that.

Now as to cams, I'll admit my experience there is limited, but you guys are mostly concentrating on the hot end of the spectrum so that doesn't apply either. I've run the CC 268H grind and yes I enjoyed that, but with this many cubes I don't think I need to go even that hot.
The forged pistons are because of the redline, and more particularly because of the piston speed, which with a longer stroke is higher. I and others have broken cast pistons with a 2.8" stroke, so I'm not satisfied with hypers for a 3.85" stroke. How is that unreasonable?

I like the idea of using the 350 crank. I can turn down the mains on my 15" LeBlond lathe before having the crank ground. No extra expense. Offset grinding though? That'll cost me. I think I should avoid that if I can.

Jim

 

Rig up a pair of offset chucks and rough out the new stroke on your lathe too.
Leave about .020" for the grinder to clean up and prepare to re-indicate everything again before the final passes.
Spare no equipment under-utilized and you must. do. a. max. effort. build.
It is the law here. We want to see new things.
We are bored reading about blase' 300hp builds (jerk off motion).
Just kidding!!

 

This is what it says in the TA catalog for their Rover heads;

"The major area of improvement in the performance of these heads is the improved intake and exhaust ports. Out of the box, these heads flow 225 cfm intake and 135 cfm exhaust. With porting, this head can easily yield 260 cfm on the intake and 190 cfm on the exhaust ports. In addition, the valve angle has been adjusted to 13° to put the valves on the centerline of the bore which allows for the use of larger valves, up to 2.02” intake and 1.60” exhaust. The exhaust ports have also been raised 3/4” to help improve performance. These heads also feature a 1.850”-1.900” valve spring install height which allows for the use of higher lift cams. On 10.5:1 Compression engines, out of the box performance is usually 40+ HP."

With 225 un-ported flow, those heads have the potential to easily make 450 + HP!(the simple rule of thumb intake cfm x 2 = HP potential for a v8) Use a solid roller cam and the HP potential goes up with duration @ .050" and RPM!

So your minimum HP will more likely be closer to 400 without even trying than 300. Spinning to 7,000 will probably get you an easy extra 50 HP unless the cam is under the max flow lift range where if that was the case a lot of potential can be left on the table.

Seeing how you have a lathe, if in you wanted to you could make your own billet roller cam blank like we discussed in a different thread. With your time frame I don't see any reason why you couldn't do that if you wanted to. Making your own cam you can control the bearing clearances more to your liking. For example, the Federal Mogul bearing catalog I have says bearing clearance for the cam starts at .0005" to .004", that's quite the large range for a Buick engine! Seems like if in those were tightened up a bit to the tighter side of the tolerance a couple more psi of oil pressure can be maintained? Install the bearings, get the bore gauge out then make the cam to the clearance you want.

Add these sbc solid roller lifters;

https://www.ebay.com/itm/Howards-Ca...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

Made in USA for about $440 less than hyd. roller lifters that are sold for the sbb. With a little bit of pencil grinding the slot about an 1/8" longer closer to the other lifter to fit in a sbb block is time well spent to save that kind of coin.

Here is an import option hyd. for even less;

https://www.ebay.com/itm/Fits-Chevy...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

Now an import solid;

https://www.ebay.com/itm/SBC-CHEVY-...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

Same deal with both the imports, the slot needs to be lengthened so they slide in the sbb's closer together lifter bores.

There are even made in USA maximum effort hyd. rollers lifters just over $400 out there that could be altered the same way to work in a sbb;

https://www.ebay.com/itm/Howards-Ca...ash=item2a970b0049:g:NkwAAOSwP4FaGAu1&vxp=mtr

The above lifters have the check valve so they are anti-pump up for sustained higher RPM. Odd how these look like the hyd. import lifters?

And made in USA hyd rollers good for good to 6,500 RPM just under $400;

https://www.ebay.com/itm/Howards-Ca...ash=item4d0c01131c:g:QpUAAOSw62VZ14qZ&vxp=mtr

Here is something else that will help save some $$$;


"There are two options, shaft mounted roller rockers (TA 1309B) or Chevy style pedestal mount roller rockers. TA offers a wide variety of pedestal mount roller rockers (TA 1309C/D series), or you can use any other Chevy roller rocker but pedestal roller rockers will require the use of our guide plates (TA 1309GP - $35.00). Note: Requires the fabrication of a lifter tray cover. Uses 11/32” diameter valves 5.060” in length."

You can use sbc roller rockers with the TA Rover heads, I can pm you some sbc shaft rockers that with a little bit of machining will be better than the Buick style aftermarket shaft ones that can be bought for a fraction of the cost that won't require guide plates.(and they're on sale right now)

I get it now, you want to do a sbb 300/350 that makes at LEAST 300 HP, what you forgot to say was "at the wheels"! LOL

 

Build it 'til your butt tingles the way you like it.

 

Art has some roller blanks already made up. The only problem is that they are set up for the Rover concentric front cover (gerotor type crank driven pump) so there is no provision for an oil pump drive and they have a short snout. Two of them have Chevy style 3 bolt ends but it could be tricky adapting that. He and Dan are sorting out profiles, heat treat and such, so that is a possible option. Art has a hundred or so roller lifters also, not real sure on the specifics. I don't particularly want to put in the time to machine up a cam blank but when the time comes I might consider it. The gerotor is supposed to be a better pump and I don't doubt it, but I'm not sure I'd have clearance for the filter. Still it's another option. But odds are it'd cost me around $125 to find out.

And that applies to the rockers too (other options). I'm inclined to stick with the shaft style rockers because they are inherently more rigid than stud mount but won't make any decisions there until I've had a look at the heads that come with the engine and know the condition of the old hardware.

Might not need to get that fancy anyway. The 268H is workable, though there is a Crane that I liked better. Might still have the specs on it. Lift is under 1/2" so no extreme geometry to deal with. The stock setup actually works quite well, though the advantage of the roller cam as I understand it is that the profile can provide both better top end and better idle than a flat tappet is capable of. Do you guys have any verification of that theory? You think it makes enough sense to go to the trouble?

Jim

 

Jim, with the TA Rover heads you have NO choice but to run aftermarket rockers because right there in TA's catalog they state that stock rockers will NOT work with their new heads. So your off the shelf choice is the TA shaft rockers or the sbc pedestal rockers according to TA.

I was going to shave with you how to use aftermarket sbc SHAFT rockers if in you're interested?

 

Huh. That's a surprise, the stock rockers work fine on the BBB TA-SE heads. I would have thought, these being a Rover replacement that they would be compatible with BOPR rocker shafts. How about that?

Sure Derek, bu all means. I'm curious.

Jim

 

I think you need to read the product description from the downloadable TA catalog before you buy these heads so you know a little bit more of what to expect;

"TA Performance’s Rover V8 aluminum cylinder heads are
the best performing heads for the popular Rover V8 engines
produced from 1967-2004. Based upon our V6 cylinder head, these
heads are a great improvement over the factory and other
aftermarket Rover cylinder heads.
The major area of improvement in the performance of these
heads is the improved intake and exhaust ports. Out of the box, these
heads flow 225 cfm intake and 135 cfm exhaust. With porting, this
head can easily yield 260 cfm on the intake and 190 cfm on the
exhaust ports. In addition, the valve angle has been adjusted to 13° to
put the valves on the centerline of the bore which allows for the use of
larger valves, up to 2.02” intake and 1.60” exhaust. The exhaust ports
have also been raised 3/4” to help improve performance. These
heads also feature a 1.850”-1.900” valve spring install height which
allows for the use of higher lift cams. On 10.5:1 Compression
engines, out of the box performance is usually 40+ HP.
Another feature that was incorporated during the design is
the new 35-37cc combustion chamber shape. Factory Rover cylinder heads feature a D shaped combustion chamber. The new
TA Rover head features a Heart shaped combustion chamber found on all high performance cylinder heads, including our V6
and big block heads. This results in better combustion and a decrease in the possibility of detonation, due to the more compact
chamber, which increases performance. The chamber and deck thickness was also increased to at least 5/8” or thicker. This
makes the heads stronger so they can handle more power without flexing and cracking, a potential problem on high horsepower
or forced induction engines. The valve cover rail has also been raised to make way for additional material which gives you the
ability to raise the intake ports to make it a tall port head. A raised runner provides a more direct flow to the valve resulting in
additional CFM over the standard port head, approximately 10-15 CFM on average. Accessory bolt hole patterns for both the 14
and 10 bolt Rover heads have also been incorporated so that the heads fit the early 14 bolt and the later 10 bolt Rover blocks.

While this cylinder head was designed for the Rover V8, it will also bolt on to Buick 300/340 blocks with minor
modifications. The stock Rover exhaust should bolt right up, but as the exhaust ports have been raised 3/4” fit there may be
some fitment issues on some cars. In addition to the Rover valve cover bolt pattern, the 350 Buick valve cover bolt pattern has
been incorporated on these heads allowing the use of 350 Buick valve covers for better clearance with roller rockers or for those
looking to use these heads on a Buick 300/340. These heads will require new rocker arms, the stock rocker arm setup is not
compatible with these heads. There are two options, shaft mounted roller rockers (TA 1309B) or Chevy style pedestal mount
roller rockers. TA offers a wide variety of pedestal mount roller rockers
(TA 1309C/D series), or you can use any other Chevy roller rocker but
pedestal roller rockers will require the use of our guide plates
(TA 1309GP - $35.00). Note: Requires the fabrication of a lifter tray
cover. Uses 11/32” diameter valves 5.060” in length.
TA 2150 PRICING
Assembled $2,808.90 Bare Castings $1,500.00"

It looks like they moved the valves closer to the centerline and spread them apart a bit so they could fit as big as 2.02" in. and 1.60" ex. 11/32" valves! That's why the stock rockers WON'T work, they won't line up with the valves anymore in their new positions.

 

OK, that makes sense then. These pedestal chevy rockers they mention, are those the paired up ones with the short shaft then? I'm not at all familiar with what is used on the new LS engines. I'm sure those would be rigid enough though. Good to know about all these little or sometimes not so little additional expenses before hand, I really appreciate you guys pointing those out.

Jim

 

They're calling regular stud mounted non-offset single sbc rockers, pedestal rockers for some reason that they claim will work with their guide plates in the TA Rover heads. They have a couple different sbc stud mounted rocker sets listed in their downloadable catalog that they sell for the Rover heads if you look.

With the Buick heads(sbb and the BBB heads) having an offset rockers from the factory I would think that the same issues would be there with the TA Rover heads as there is with the BBB Edelbrock heads because of the pushrod to valve misalignment. Even more so with the TA Rover heads because the valves were moved farther apart from one another than from the factory making the angle even worse. Even using TA's "special guide plates" the geometry would still be off and limit lift so the rockers somewhat stay under control like the PIA the guys with the BBB Edelbrock heads have?

 

1.Yes
2.No, depending on if the dollars are priority.

Shorter seat to seat duration can help idle and throttle response if the specs are right, of course.
The shorter set duration being taken advantage of by the roller having a more radical profile, and intentions of making it up on the lobe.
More degrees of rotation with the valve at higher lifts due to the cam profile being more aggressive can help the entire powerband (including top end) also with the specs being suitable, of course.

Actually plotting out some mild roller cams as suggested by this build's needs might be an eye opener.
A flat tappet with some rocker ratio helping can easily equal the roller until the cams both get wilder, or completely negate the cost factor if break in and oil issues aren't considered.
I don't bother with rollers until the project gets really serious (if it's on my dime), meaning when there's absolutely no comparison.
For example, on a 380-410 sbc having 250-260* @ .050" , .625" lift...I'm better off with a solid flat over the roller due to minimal power gains and the fact that I can tune out negligible idle probs....unless they are ecstatic to pay the +$1200 and the rest of the budget is generous.
I could put the same $$ into airflow and find the same result until everything becomes max effort, and there again you can spring for better castings to start with.

For the small Buick build here, airflow could easily cover the difference assuming the dollar was top priority and depending on which castings used.
You could easily save some cash not using a roller cam or aftermarket heads, and put a little bit into porting the better of the cheaper castings while achieving your goals.

 

Yeah, so what I'm hearing from you guys is the best bang for the buck here is going to be putting the money into porting the 300 heads. Might even manage a deal with Dan for a set that have been done if he's not using them. I'll definitely think about that.

Considering all the extra added on gotchas it really looks like the TA heads are best left for an all out race engine, just because of the costs involved in all the extras needed to use them, and then probably ported. I think I'm getting the perspective here. I was making invalid assumptions. I thought it'd be much like our experience with the SE heads, but apparently not.



Jim

 

I'm not following or commenting on any of the details of the build or much of the needs or priorities from your perspectives.
I like to steer clear of that.
Just replying towards basic machining and component selection and induction needs as described.

 

TA did what they did to the heads to help make them flow some air. And they give you the options to use sbc rockers. You can even use factory sbc rockers if you want to use some sort of "stock" rocker. The ball and stud rockers are a bit more forgiving than the roller stud mounted rockers for using with the incorrect geometry. You said you wanted to keep the cam on the more mild side so the factory sbc stamped steel rockers with TA's guide plates should work just fine for you.("or you can use any other Chevy roller rocker but pedestal roller rockers will require the use of our guide plates(TA 1309GP - $35.00)" right from the TA catalog) Again, TA is referring to stud mounted when they say "pedestal rockers".

Factory sbc rockers are dirt cheap and $35 for the TA guide plates sounds reasonable. You don't have to run the TA $1,400 shaft roller rockers, you can run the factory sbc setup for less than $100 that includes the $35 guide plates, or the roller alternative I sent you instructions for if you want to use the TA Rover heads.

I wasn't trying to talk you out of using the TA Rover heads, just wanted you to be more informed going in.

 

Thanks, I've not counted them out by any means, just want to be sure I'm doing the right thing when the time comes. Buying the bare heads will be a bit of a stretch to begin with, I'm sure most here can relate. But, one I might be able to justify. Sort of similar in some ways to the custom pistons. But to do those things I have to find other ways to economize. So obviously I'm looking for the best ways to do that without cutting corners. I'm really not a fan of chevy's stud-n-ball rockers, especially not after someone on here tried to adapt them to a SBB with a mounting plate and proceeded to break things due to flex. I saw that one coming. But they can and do work if the heads are made for them and if that's the only inexpensive option... Might need to keep looking into the paired shaft rockers though. Olds used an interesting variation on that theme on their 350.

Jim