The Blue Truck

[99_ls1]

...a quick runner/driver and full restoration look a lot alike.

Oh, this is a lot rougher and cheaper than it looks. I described gobs of bondo but it was up to 1" thick in several places! It was also a biological waste dump with dead mammals that were there when I got it, BEFORE I parked it under the trees.

I will have zero bodywork and about $600 in paint that will last a year. The only reason I was gonna shoot the 2K clearcoat on the outside is to help it survive while bodywork happens panel by panel. I have not found somebody who wants to beat on this heavy sheetmetal yet!

The interior I am trying to finish off reasonably, but the exterior is nothing but a mess and will stay for now.

[99_ls1]

Sweet - dual master for four wheel drum - which resevior feeds which end of the truck? Which prop valve?

Front == Front
Rear == Rear
Proportioning valve is not F-Body as the booster was, not 50's truck, not 60's truck, not 50's or 60's Corvette, I don't think it's a first-gen GTO or Lemans or the like. So, it's square, that's all I care, since both ends are drums...

I am continually shocked at the price of insurance for newer vehicles.... legalized extortion.

Oh, please don't get me started on the legalized private taxation...

[mlcraven]

Wonderful project, it's hard not to love old trucks.

[99_ls1]

Okay, so I feel like a professor giving a lecture :D So, I will ask a question: Which of these two long blocks would prove to be better for this application:

Exhibit A: 1985 305 H.O.

Exhibit B: 1962 283 short block, '85 Corvette L98 heads, 1.94 1.60 valves. I have both a 3" and a 3.25" stroke steel cranks, so it could be a 283 or a 301 - however the side load increases with the larger stroke.

Either way, the winner will have an appropriate for the chosen heads retrofit COMP roller drivetrain and the TPI/Megasquirt 3 which we already have shown perched on top of the 283.

There really are only two major variables in this choice. One is to have decent torque to get off the line to get this beast moving with a 3:08 or so rear gear. The second consideration is that I plan to utilize the Megasquirt to maximize the fuel economy.

These are two separate and divergent goals I realize, but I figured I'd throw it out there too see what kind of thoughts are out there.

Which would you prefer? 283/301 or 305?

[trukluvr]

Looking great. Love old trucks!!

[Deaf Bob]

I would go 283/301..
Thicker castings.. Supposedly can be bored up yo .120. I'd stop at .060 to be safe..
Keep in mind the 283 is probably a small joural crank

305 is a small bore 350..

[99_ls1]

Casting thickness really isn't playing into it, I will explain a little more.

The question I was asking really was - which bore/stroke combination would better for the intended torque/economy, and regardless it will be fuel injected and tuned by myself.

I was asking which might be better - a shorter stroke/larger bore, or longer stroke/smaller bore question.

The 283 has a 3.875 bore and a 3" or 3.25" stroke.
The 305 has the 350's 3.48" stroke and a 3.75" bore.

If the 3.25" stroke crank is used it's only a difference of 5 cubic inches or so. The 305 has a longer arm for grunt against the crank, however it's bore is smaller and by design has less surface area for the flame front.

I can get a well-built steel crank .030 305 with Eagle Rods and JE flattops for very little and use the 461 heads I have which are perimeter bolt so visually things will look identical.

Or is this mechanically a completely irrelevant question?

[SuperBuickGuy]

You ask a question which is a lot of opinion (and a lot of "that's what I have sitting around"). IMO, long stroke is overrated when you're dealing with a light car (less than 3500 lbs, good gears). first of all, the 305 is hated (350 crank, small bore) because of the heads. 2 valves just can't flow enough air/fuel to make huge power. However, Ferrari has been using small bore/long stroke forever with amazing results (it also has a flat crank and 4 valves).

the 302 motors (even Ford) have 4" bores and short stroke and can rev to the moon because there's less stress at the rod end and the valves are unshrouded (the cylinder wall isn't as close to the valve, thus allowing better flow). Of course, as we know, you give up torque for that better flow. So you have to have a light car and/or higher (numerically) gears.

I went through this debate when deciding what is next for my Corvette - right now it's a good-running 350; but it's never enough. I didn't want turbo(s) or a blower, but I wanted high hp and am willing to give up some torque because the car weighs less than 3500 lbs. I don't have high (numeric) gears, but I do have a Super t-10 with a economy 1st gear - so it should be fine. Of course, I wanted more than 500 hp; and to do that with small cubic inches would put the rpms into the range where my pocketbook would scream (the better the parts, the more money). I'm going to build a 427 BBC. Another consideration (in my case) is I wanted stronger architecture of the block, and a large bore - and the BBC is physically stronger than a SBC.

anyway, hope that gives you some thoughts to help with your build

[99_ls1]

Thank you SBG, exactly what I was hoping for was some opinions - they're like noses everybody has one and I wanted to hear what the board wanted to say. I'll readily admit that this informal survey was based on nothing but opinion, mine included, inventory included, and was left wickedly wide open for a reason...

My application is exactly opposite from SBG's. This build is for someone who won't abuse it and won't be racing it. She's looking forward to having her "Cowboy Cadillac", and has asked if it will get decent mileage. I'd like to be able to surprise myself with it - for the last TPI I did was on a ZZ4 short block with 1083 iron heads and I got 17.5 around town and 23+ on the higway in a '65 C-10 with a 700R4 and 3.73s in a 12-bolt over a 10-year period and 55K miles.

So I have several long-blocks here all of varying age and journal size. I have been thinking about the journal speed of the small vs. the large journal stuff vs. the idea that GM itself considered the 305 an "economy" engine also according to whatever "new math" they were touting at the time in elementary school... I suppose they had an engineering reason to go with the bore/stroke combo of 3.75 X 3.48" but was it bean-counter driven or based on a real economy advantage? Based upon the weak-suck performance levels of the time, a 305 is just reviled, yes. And the parts generally were made better on a whole due to advancing technology but they aren't exactly "better".

I can do a 283, a 302, two different 305s, a mid-70s 4-bolt 4" bore, and a late 80's L98 350 with OEM roller. That covers all three bore families (3.875, 3.671, and 4") and a reasonable range of stroke possibilities with small and mid-journal sizes. I could stick the small-journal 3" stroke crank into the real 4" bore small-journal 1967 block I have and have a real deal 302 - but the RPM it wants to romp by its very architecture negates the entire purpose of the question.

So, the motor is going into a heavy pickup, with numerically low gears, using a torque-based induction setup, a non-racing driver, and with all those factors combined, I guess I probably have answered my own question - and the answer is I am looking for is that I am essentially asking a stupid question - low power, low rpm, heavy truck, around town, loaded engine.

When I look at the rod/stroke and the stroke/rod ratios and they do vary significantly, so therefore was the reason I stuck it out here whether it generated a rugby scrum or not :D

[CTX-SLPR]

Honest and potentially not very informed opinion... L98 350. Simplest route to what your after from what I know, has the stuff to make a roller cam a bolt in swap, is what you're using for heads on everything else, and the displacement and bore will make it easier to get the torque curve you want.

Baring the expanded choices, I'd say the 283 with a stroke to it. 305's seem to give decent mileage in stock form but they also seem to be more knock prone which could be a problem with more torque (higher cylinder pressure) and keeping it running on 87oct gas.

[gearhed1971]

Turbo charged blue flame six!!

[Scott Liggett]

Build the 350. For torque, you want displacement. Period. Put decent heads and cam on it, and you will build more than 400 ft lbs of torque below 4000 rpm's peak. That's what moves the truck down the road.

Yes, the larger bore is good for allowing larger valves without shrouding them. That means the air can move around the entire cirucumference of the valve. That allows horsepower.

[milner351]

If I read it right - you have a block that is factory roller? use that - end of story - factory replacement roller lifters are soooo much cheaper than retrofit roller lifters that my mind is already made up. Use the best heads you have with the largest valves, best chambers to get you a ~10:1 CR which you can tune with head gasket thickness given all the sbc choices. Given the highway gears - torque is king as stated - if you can build a 350 with parts on hand I'd do that and not even consider the smaller engines - save those for lighter cars. I've put some miles on 305 factory trucks... no thanks - 350 all the way!

[99_ls1]

Gentlemen, thank you for the opinions. After thinking about the little bore trying to shove this big truck, you all are right. However, economics being what it is, it's time to take a half-step.

The 305 is roadkill, that is a given. However, I have access to a 305 short-block that was machined, balanced, and mocked up as a short-track engine 10 years ago. Eagle bronze bushed rods with ARP hardware, forged floating JE flattops, and a cast crank with all the trimmings that could be done within the "stock" rules at the time. With the 58cc heads it should be right at 10.25:1. It was to be a backup engine and was never assembled. The heads ended up being sold off years ago and he's had this tucked away in the corner forever, I wondered what it was hehe

I cannot pass this option up because of timetable and cost reasons - for in the scope of the world the components are almost free and assembly is somebody's favorite thing to do!

In the meantime, I will build up the parts list to build the roller L98 as a TPI 350 as it was intended. We'll use the 305 for the short term to get rolling, then introduce the TPI to the 305 with the Megasquirt to get the kinks ironed out with that, and then build the L98 and locate a 700R4 and do the swap at a later time.

We've spent the weekend painting the doors and small parts, completed the FatMat up down and around, and discovering the engine is junk. Hopefully we can enlist some help for next weekend from somebody who knows how the he!! to install windows because I will bust one in a heartbeat!

I'll post some pics later once something is worth posting.

[milner351]

Well done!