Can Am racing

[tt 383]

It's my understanding the ZL1 blocks strength wise were not great, just in the theme of weight reduction. We're they even used in this application, I have read different accounts of what the initial liner blocks were? How strong were the liner less blocks? We're they a completely different casting/tooling? Seems they would need to be siamese casting or some special proprietary material for what they were used for.

[Steve.k]

Just a couple of old tidbits about the 430" Can Am bbc. Unlike the iron sleeved ZL 1 block, the can am piece was 4.44" bore all aluminum. Needed specially coated pistons and rings. Short stroke crank also. All chevy stuff. The team I worked with went from Trans am to Can Am with 2 older McLaren cars. That was back in '71-'73. Lucas timed fuel injection was fuel system of choice for them. Cool stuff.

A minor clarification: The original design 4.440" bore aluminum Can Am engines were sleeved and used conventional pistons* Prototype versions were used as early as 1967 in Jim Hall's Chaparrals (direct from Chev R&D) . Although externally similar in appearance, it varied in many design details from the 4.250" bore ZL1 aluminum production big blocks and was never assigned an alpha-numeric engine designation. They were sold only as bare blocks or parts kit and many were either built without or migrated from the special 3.47" crank which gave 430" to the 3.76"/427" or the 4.0"/454 crank, the latter giving 495.5 c.i. (*I know, I've had one in my garage for 40+ years...)

The later linerless 390 high silicon alloy Reynolds blocks (circa `1971) started out at the same bore, but could be machined to 4.50" and beyond.

Bill did the chaparrals not race against shelby and ford at lemans? I wonder if they used the 427 in can am? I know shelby mentioned in his book the chaparral was coming on hard at tail end of Fords lemans program. Those were Jim Halls cars also.

[Daniel Jones]

Ford also has the 427 3-valve "Calliope". It was an offshoot of Ford's Can Am engine development intended to run at LeMans in 1968 but rules changes made 7 liter engine illegal. Though it displaced 427 cubic inches, the Calliope was not an FE family engine. Instead it shared bore spacing and bellhousing pattern with 429/460 BBFs. It used an aluminum block with cast iron cylinder liners and had a bore and stroke of 4.34" x 3.608". The aluminum cylinder heads have 3 valves per cylinder, two intakes and one exhaust, in a pent-roof combustion chamber and the heads are sealed with copper O-rings. No intake manifold is used. The sliding throttle plate independent runner stacks were cast integrally with the cylinder head. Twin water pumps, one on each bank, were used to shorten the engine. Twin camshafts in an over-under arrangement were also used, one for the intake valves and one for the exhaust. The intake camshaft was 6" above the crankshaft centerline. Pushrods from the intake cam run parallel to the cylinder bores. The exhaust camshaft is 4.5" above the intake cam with pushrods in a horizontal plane. The camshafts were driven by chains, along with the dry-sump pressure and scavenge pumps. Pictures are here (check out the wing on the G7A):

https://www.gtplanet.net/forum/threads/ ... am.310223/

Dan Jones

[MadBill]

i don't know much about the Reynolds-cast blocks, but I believe they were much revised, not just the alloy change.

As to LeMans, Hall did run two Chaparral 2Fs there in 1967 with 427" aluminum engines, qualifying one 2nd behind one of the Ford MK IVs, but neither finished.

[pamotorman]

390 Reynolds block

[Newold1]

These Reynolds aluminum silicate blocks sound like the same methods that Jaguar used in the original AJ 4.0 liter V-8 DOHC engines in the 1996 thru 2000 years. They were dropped for steel liner blocks because sulfur in fuels then were raising havoc with ring and bore wear.

IN Can -am overall car weights over 1600 lbs made the V-8 engine cars uncompetitive until Porsche killed them all with turbocharged 1100 hp screamers. That was pretty much the end of Can-am !

Gone but not forgotten! Still remember sitting on the open bridge at Laguna Seca in 69 looking down those stacks and feeling the roar and rumble under my butt when those monsters flew under! AH, what a glorius time and sound!

[tenxal]

I can't believe though no one made an effort to cast some aluminum heads back then. Chrysler was going full-bore in drag racing and aluminum heads could have been a benefit to those guys too.

Chrysler aluminum Hemi heads were plentiful and very common in that time frame. The '65 A990 cars had aluminum heads, for example.

[j-c-c]

Re:Madbills post.
Honda has never officially lost an engine that was anything but an "electrical problem! Disregard the smoke and flames!

We used to call that "visually overheating"

[pamotorman]

I can't believe though no one made an effort to cast some aluminum heads back then. Chrysler was going full-bore in drag racing and aluminum heads could have been a benefit to those guys too.

Chrysler aluminum Hemi heads were plentiful and very common in that time frame. The '65 A990 cars had aluminum heads, for example.

one of the problems with aluminum heads back then was durability. water leaks and seats falling out were some of them. GM BBC aluminum had problems with the guides slipping down. the first L-88 corvettes had their aluminum heads replaced with CI for the 24 hour races for that reason

[tpepmeie]

the first L-88 corvettes had their aluminum heads replaced with CI for the 24 hour races for that reason

Fascinating. That’s the first I’ve heard of that and I’ve been following/researching corvettes since the mid 90s. Where can I find the rest of that story?

[grandsport51]

This link shows the Prototype as to what heads were on it iron or aluminum I have no idea
and it discusses the first 4 production L-88s in 66
http://carguychronicles.com/2018/02/65- ... first-l88/
Dave B

[Newold1]

I personally picked up in late 1967 what I was told at the time was one of the first shipments and delivery of a crate L-88 engine. It was anopen chamber iron head equipped engine. I know GM was out with the aluminum heads for the big block in 67 but they were not used on the L-88"s at that time.

[pamotorman]

the first L-88 corvettes had their aluminum heads replaced with CI for the 24 hour races for that reason

Fascinating. That’s the first I’ve heard of that and I’ve been following/researching corvettes since the mid 90s. Where can I find the rest of that story?

i was told this by my contact at GM racimg. it was a traco built engine that replaced the origimal aluminum head engine for the race.

[pamotorman]

I personally picked up in late 1967 what I was told at the time was one of the first shipments and delivery of a crate L-88 engine. It was anopen chamber iron head equipped engine. I know GM was out with the aluminum heads for the big block in 67 but they were not used on the L-88"s at that time.

interesting as I had a set of early open chamber heads and they were sand cast with different configuration around the exhaust ports. the head bolts around the exhaust port side were counter bored down into the heads where the bolt heads were recessed below the surface of the heads. the easiest way to tell the difference between production open chamber and production closed chamber on the engine is by the shape of the exhaust port on the outside. the closed chamber heads that surface was flat and the open chamber that surface is rounded.

[DanE1]

At one time in the late 60's, there were 2 Can Am cars in my garage. One Lola, and one McLaren. Both were powered by aluminum "430" inch BBC's putting out around 650 HP. We took the Lola out to the freeway late one evening. Damn thing sure was fast for that era.

I want to hear more about that night!

Jeff;
I worked with my father in his residential home building company. A man named Tom Swindell came to us and wanted us to design and build an English Tudor style home complete with a moat and all furniture built to the era. The arrangements were made and he put his existing home for sale. Well, his house sold in the first week and he had nowhere to go.

I had a large house with a garage built for hot rodding cars, and I told him that he could live with me untill we finished his house. He showed up with the two Can Am cars and a B Production corvette. One evening we were sitting around talking car control and I told him I had been involved in "on the edge" car control for years. Well, it seems, the challenge was on and off we went in the corvette and what we took turns doing was on the "edge", to say the least. I was now a co-driver in the B Production corvette.

Now to the Lola. The engine was out getting freshened up, and when it was back and installed, Tom wanted to take it out and see how the engine performed. We put the car on a trailer at 4 in the morning and took it to the 96 freeway that runs between Detroit and Lansing to run it. Now, I had been running high powered cars on the street for years, but nothing that accelerated or had a top end like that Lola, nothing even close. There were not many cars out, and we blew by them so fast they were like a blur and their door handles were above our heads because the Lola set so low. Another person had taken the trailer to the end of our run and was waiting for us. We loaded the Lola up and got out of there. Tom was eventually killed doing his exploits and I still miss him. He had gasoline in his veins.