Im B'ville dreaming again. Any thoughts?

[Beck]

I've been having some down time at home, and talking with Hooley a little. That combination has again lead me to thinking about a Bonneville car of my own. I have posted a few times in the past while considering certain engine classes. My small mind is again filled with dreams. Unfortunately I know just enough to get into trouble sometimes. So I come to the pros, you guys.

There was a Bonneville story in Hot Rod 2 months ago. One class that jumped out at me was F/CRRO. Classic classes are 1981 and older. Classic classes have always been limited to US cars. Last year they opened the F size engine Classic Production to foreign cars. There was a VW Karman Ghia that ran in the class last year but couldn't complete it's backup run so the class still has an open record. The F motor class is 2 to 3 liter or 123 to 184 cubic inches.

I looked at some of the options. The Nissan 280ZX (2.8 liter) looks promising, but I think it falls into the Grand Touring Sport not Production. Then I stumbled across the Alfa Romeo GTV6 (2.8 liter). It would probably be the car to run, but finding one would be difficult and the expense prohibitive. Again I don't know where this car would fall, Pro or GT. I briefly looked at the Mercedes 280 (2.8 liter). Then my thoughts turned away from the foreign cars. The 2300 Ford 4 cyl in a Mustang II? Coswerth Vega (2 liter)? Early Chevy II with a Chevy I4 (up to 181 ci)? Iron Duke (2.5 liter) in a Monza? All of these have potential.

Then I thought back to my Bonneville trips and I recalled guys running small block Chevys on 4 cylinders. Some internet research led me right to Sumner's page. Initially Sumner was considering powering his streamliner with half a V8. He has a page on his site about it.
http://purplesagetradingpost.com/sumner/bvilleother/page%205.html

Reading Sumner's page I realized it would be possible to build a full V8, not half, to the 184 ci limit. Larson/Cummins did it in the mid 60's with great success. From the Feb 2009 Rod and Custom, http://rodandcustommagazine.com/thehistoryof/80458/

"Two engines were built: one for the D class and one for the E class. The engine size could not be any larger than 183 ci to compete in D class and 120 ci for the E class. Fred chose the Chevy V-8 for both classes. A '59 265 block with a 5/8-inch destroked crank was used to create the 183ci V-8."
"Heads were from a 283-inch Chevy. With a 4-71 GMC blower, the estimated horsepower was 450. "The little 180-incher is the smallest Chevy V-8 I've heard of, Fred says. "For the second motor, I wanted 120 inches. After building the 180, I knew I couldn't get a Chevy that small and still get valves in it, so I built a 240 and left half the pistons out. I staggered them; every other one in the firing order was left out two center pistons on one side and two outer pistons on the other. The Potvin blower hung right on the front of the crank. That gave me my 120 inches."

Using the 2.375 stroke Rod and Custom published, my math shows that Larson/Cummins had to have sleeved the block to just under 3.5" but that isn't stated in the article. Anything less than a 3.5" bore and valve clearance becomes an issue.

Chevrolet produced a 267 SBC from about 1978 to about 1984, a decade after Larson/Cummins built their motors. This is the smallest bore SBC built at 3.5". Using one of these blocks would eliminate the need to sleeve to reduce bore size. The stroke would need to be about 2.3" depending on the size of overbore necessary to clean up the block.

My big question - Is there an economical way to destroke a crank that far? Starting with a 283 crank (3" stroke) that is a reduction of .7". If the crank was to be welded and reground the oil passages would become an issue, correct? I wonder if the billet blanks that the new crankshaft grinders use would even work. Everyone wants more stroke, so the blanks would be designed for this. Using the Honda size rod journals would help a small amount. The local tractor pullers commonly have stroker cranks welded up and reground. Will this live at Bonneville?

There is a cheap set of used Nascar Carillo 6.35 rods on fleebay right now. They would be about the right length. I don't think the aftermarket makes performance SBC 3.5" pistons. I did find a set of Nissan pistons (89 mm) that may come close but since that is a 4 cyl engine I would need to buy 2 sets which would put the pricing at nearly what a set of custom ones cost. The rods have small Nascar style pin holes (.827") so stock type SBC pistons will not work. The Nissan pistons do have the right size pin hole. I'm unsure of the Nissan piston top configuration so compression ratio hasn't been looked at.

Another question is the rod ratio. 6.35 rod length / 2.3 stroke = 2.76  Here is where I am stupid.. Is this a grenade with the pin pulled?
With a stroke this short would I have to really rev the motor to make decent power? If so what do I need to do to the valvetrain to make it live?? I'm looking at 305HO heads, small 4bbl carb. Are the ports too big in the heads and an aftermarket aluminum intake? Single plane or dual plane?

I keep spiraling deeper! Maybe I should just keep dreaming and enjoy my time in the 974 pit. That would be a lot easier.

Any and all thoughts would be appreciated, SBC, a different combo, or "Just don't do it" like my mother says.

[wayne petty]

i wonder with the single rod on each throw designed for 2.. i guess that the crank grinder would just weld up the empty half of the rod journal to make up some of the missing weight.. and leave it flanged like a spilt journal crank/231 even fire. like.  they could weld a significant number of layers on it..   i am thinking 283 steel crank.. along with drilling the snout for the damper bolt installation.

don't forget that down in the south is the used nascar parts place... one might find some really short cranks there..  maybe even some really long rods.. with honda size big ends..

wonder if it would be easier to use a variant of the 4.3V6 chevy motor... as they made chevy 200 cubic inch V6 motors in the late 70's  might be easier to sleeve down and destroke a 200 cubic inch motor to get below the cubic inch limit..  since there are all kind of intakes now for the V6 chevy motors..   buick also had a 198 V6 in the early 60s.. before they bored and stroked it to the 225 oddfire.. there are oddfire HEI distributers so lighting the spark plugs should not be an issue.. 76 to 78 just before they went to electronic spark timing that needed even fire cranks to operate properly..  one might even be able to use dual crank sensors to run a dual sightly offset DIS ignition system.


i don't know the internal structure of the early buick V6 blocks or the 200 chevy to know if there is enough bulk head strength to prevent the crank from ripping the main saddles out of the block...

[Beck]

I stated in my first post that the Nissan pistons I found were 89 mm they are actually 89.5 mm which would be just a bit more than .020 over the stock 3.5 bore.

[Beck]

i wonder with the single rod on each throw designed for 2.. i guess that the crank grinder would just weld up the empty half of the rod journal to make up some of the missing weight.. and leave it flanged like a spilt journal crank/231 even fire. like.  they could weld a significant number of layers on it..   i am thinking 283 steel crank.. along with drilling the snout for the damper bolt installation.

The most common crank setup when running one bank of a V8 is using the bottom half of the rod on the unused cylinder or machining a bob weight to take the place of the unused rod.

don't forget that down in the south is the used nascar parts place... one might find some really short cranks there..  maybe even some really long rods.. with honda size big ends..

Most of the Nascar stuff is SB2.2 or newer. In the Classic classes the motor type has to have been available in the vehicle which has to be
'81 or older. That lets out all of those cranks.

wonder if it would be easier to use a variant of the 4.3V6 chevy motor... as they made chevy 200 cubic inch V6 motors in the late 70's  might be easier to sleeve down and destroke a 200 cubic inch motor to get below the cubic inch limit..  since there are all kind of intakes now for the V6 chevy motors..   buick also had a 198 V6 in the early 60s.. before they bored and stroked it to the 225 oddfire.. there are oddfire HEI distributers so lighting the spark plugs should not be an issue.. 76 to 78 just before they went to electronic spark timing that needed even fire cranks to operate properly..  one might even be able to use dual crank sensors to run a dual sightly offset DIS ignition system.

i don't know the internal structure of the early buick V6 blocks or the 200 chevy to know if there is enough bulk head strength to prevent the crank from ripping the main saddles out of the block...

I was looking at a '80 Monza locally. They were available with the Buick 231 V6. The ignition systems need to be old school to stay in the rules.

[unklian]

I think the crank billets start as a solid chunk,
oil holes are done later. So almost anything is possible.

F is 123.00 to 183.99 cubes.
Not familiar with /CRRO, must be a new class ?
Engine swaps allowed ?

[wayne petty]

I think the crank billets start as a solid chunk,  oil holes are done later. So almost anything is possible.

i can verify that.. i have been in the machine shop at keith black racing engines.  they have a crank grinding lathe. but instead of a grinder attachment.. it had a vertical mill to remove the metal.. .  i want one of those..  even if they are too big to fit in my living room..  another friend who worked at ed pink let the secret out to me that they used ball hones in reverse to knock the torn out metal peaks down on the indy car motors they built..

[unklian]

I was looking at a '80 Monza locally. They were available with the Buick 231 V6. The ignition systems need to be old school to stay in the rules.

Monza is a nice looking car.

IIRC, they were available with a SBC.

[unklian]

I was looking at a '80 Monza locally. They were available with the Buick 231 V6. The ignition systems need to be old school to stay in the rules.

Monza is a nice looking car.

IIRC, they were available with a SBC.

Anything foreign, won't have the aftermarket support
like the SBC, so parts will be more expensive.

[unklian]

Another question is the rod ratio. 6.35 rod length / 2.3 stroke = 2.76  Here is where I am stupid.. Is this a grenade with the pin pulled?
With a stroke this short would I have to really rev the motor to make decent power? If so what do I need to do to the valvetrain to make it live?? I'm looking at 305HO heads, small 4bbl carb. Are the ports too big in the heads and an aftermarket aluminum intake? Single plane or dual plane?

I keep spiraling deeper! Maybe I should just keep dreaming and enjoy my time in the 974 pit. That would be a lot easier.

Any and all thoughts would be appreciated, SBC, a different combo, or "Just don't do it" like my mother says.

Rod/stroke ratio doesn't mean much in the real world.
Going real short on the stroke, rpm will have to go up
to make it run real strong. Which means $$$ for valvetrain.

Single plane is for serious performance.
If necessary, making the intakes smaller is dead easy.
A flow bench and some math will tell you.

[GPster]

I started a post this morning but my new computor wouldn't recognize our old key board or my typing. Some strange thoughts. Mercury Marine has a 1.8L "Iron Duke" take off that is supposed to be a hot number. Pontiac made a 1/2 V8 for their first generation Tempests in the early '60s. Maybe that can give you more ideas and different sizes of parts for that idea. How about 1/2 V6 (#1#4#5)? The Chevy 90 degree V6s of the'70s and early '80s were of the old Chevy V8 design but the newer internal crank/rod sizes. Maybe you could off-set grind the rod journals to early rod sizes to increase or decrease the stroke and use early rods. And I guess there is a 7" Olds rod that circle track people used to use in Chevys to get a longer rod. GPster

[Beck]

Not familiar with /CRRO, must be a new class ?
Engine swaps allowed ?

ClassicProduction is not new. All of the Production rules apply but the Classic prefix means it is 1928 to 1981 American made, except for the F engine class which allows foreign cars. Engines are required to be of the family that was original equipment. For example a Monza can run first gen SBC, Buick V6, Pontiac Iron Duke because all were originally available in them. No big blocks or I4 Chevy motors since those familys of motors didn't come factory in them. Only factory original EFI setups allowed. Any carb setup or mechanical injection is allowed. There are also limitations on the ignition system.

[Beck]

Mercury Marine has a 1.8L "Iron Duke" take off that is supposed to be a hot number. Pontiac made a 1/2 V8 for their first generation Tempests in the early '60s. Maybe that can give you more ideas and different sizes of parts for that idea. How about 1/2 V6 (#1#4#5)? The Chevy 90 degree V6s of the'70s and early '80s were of the old Chevy V8 design but the newer internal crank/rod sizes. Maybe you could off-set grind the rod journals to early rod sizes to increase or decrease the stroke and use early rods. And I guess there is a 7" Olds rod that circle track people used to use in Chevys to get a longer rod. GPster

I thought the Mercury Marine was the Chevy I4. I know Mercury makes it in 153 and 181 ci. With work both of those cranks will work in the Iron Duke. The problem with the 181 crank is the Iron Duke block isn't deep enough to support the piston at the bottom of the stroke. Custom long rods and short pistons are required.
I have been trying to ballance aerodynamics with engine options. The Monza is a good Bonneville choice because it is pretty aerodynamic. The same tiny SBC could be run in a big early sedan, but the aero package there would suck. The 2nd gen Camaro would work with the tiny SBC also but again the Monza is more aero. The 1/2 V8 Pontiac has the same aero issues when you look at the early Tempest body. Running half a V6 would require a big V6. Half a 360 ci V8 puts you right at the 180 ci mark. That eliminates all of them.

[Beck]

Does anyone have a ballpark idea on the pricing of one of the custom billet cranks?
I know anything is possible with enough $$. I just don't have enough.
There is a local antique tractor puller near me. He builds a lot of nice stuff. He is designing a 2 cyl John Deere antique now. New aftermarket block and crank. 1005 cubic inches, in 2 cylinders. The price - he said don't ask!
Unklian -  Hooley was having a little issue with the rod ratio in the BBC he was planning. In fact he is where I came up with a "gernade with the pin pulled" term.

[phat46]

Would it be possible to run a V6 as a V4? seems it would be easier to balance.

[Mikej]

Corvair?