My 308 cu inch Long Rod Combo

Hi all

I just got back from my trip to LA. I collected the 48 IDA Webers and Cobra manifold that I won on the E-Bay auction site. The seller who lives in LA also had an alloy Cobra oil pan so I purchased that as well. After some discussion with the seller he mentioned that Hawaii Racing was just down the road and was also worth a visit for engine parts, so off I went.
I found Hawaii Racing at 21 Easy Street, Simi Valley CA 93063. Web site http://www.hawaiiracing.com/ Tel (805)583-8880
When I entered their establishment I felt close to heaven, on my left as I went through the door there was a Boss 429 overhead cam Ford,

lots of other newly prepped Ford and Chevy custom race engines.
Then I walked past hundreds of custom race parts alloy cylinder heads, stroker crank kits, alloy inlet manifolds of all descriptions and much more until getting to counter. I said that I was in LA looking to buy a few engine parts and would like some advice as to what they had to offer for a Track GT40.
I was invited into the back (THE TOY ROOM.) sat by a very shiny Ford small block was Joseph Souza the owner of the shop. After a chat with Joe I realised that this was the guy that had been the spanner man on the Hawaiian Funny car that was campaigned from the sixties and was featured in many of my old HOT ROD magazines.
Well, I ended up ordering a complete engine. The spec is as follows

Ford Racing 4 bolt main block bored +30 using torque plates = 308 cu inches.
lightweight H beam 5.4" LONG Rods
Lightweight Custom forged pistons with higher wrist pin position for the long rods.
Standard Stroke lightweight crank internally balanced, using heavy metal.
Custom grind solid roller cam
Victor Junior alloy heads
Alloy Roller rockers.
Belt drive for the cam with Venire adjustment.
Block mounted electric water pump

I left the cobra inlet manifold with Jo so that it can be matched and flowed to the heads. The alloy sump is to be modified to suite the windage tray and have two trap doors installed to control oil surge.
We decided on the long rod approach instead of stroking to improve engine efficiency reducing piston side loading, and increase compression to 12:1 because of the better combustion afforded to us by a long rod engine. I also believe this approach will make the engine very responsive especially with a Tilton lightweight clutch and flywheel set up.
The rod stroke ratio of this long rod combo is 1.8 as opposed to 1.66 for the standard stroke 302.
So what do you think about going the long rod route instead of stroking?
Also if you go to Hawaii Racing and speak to Joe it could get expensive, but you only live once.

[ October 08, 2002: Message edited by: Chris Melia ]

[ October 08, 2002: Message edited by: Chris Melia ]

 

Chris,
I knew you wouldn't fly all over the pond just to collect a set of carby's...

 

[Rick Muck- Mark IV]

FYI....the Boss 429 is NOT overhead cam. Pushrod like all older Ford V8s, just hemi-headed with enormous ports.....

Rick

 

[Gary Gibbs]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Mark IV:
FYI....Pushrod like all older Ford V8s,
Rick<HR></BLOCKQUOTE>

FYI

The old SOHC 427 was OHC and (near) Hemi. It was produced in limited numbers during mid sixties and produced ~600 HP stock.

 

[Gary Gibbs]

Chris,

Sounds like you had a fun trip. What heads are you using? I too was thinking about a Tilton clutch. Which of the Tilton clutches will fit?

Thanks
Gary

 

[Mark Worthington]

I think Chris was referring to the 427 cammer, which you used to be able to buy over the counter at certain Ford performance parts outlets.

Chris, are you using the alloy block? It sounds as if you plan to spin that engine well past 7,000 rpm with the long rod and solid roller setup. Sounds like fun!!! I would also venture a guess that airfare and accomodations were the least expensive part of your journey.

 

[Gordon Levy]

The long rod is a better engine at high RPM's. It puts less stress on the bottom end of the engine. The higher the rod ratio number the less stress it puts on the block and rotating assembly.

 

Hi all

the Boss 429 as MK1V said is not overhead cam, You can see the engine I referred to in the photo above. I was confusing the 427 SOHC and the Boss 429. This is the first time I have actually scene one in the flesh and it is for sale.

My 302/308 engine will be fitted with the Victor Jr heads, I have still to get the full details from Tilton about the most suitable 2/3 plate clutch and flywheel package.
Regards

Chris

 

[OMeyer]

Yes, it is actually a Boss 429, but after all, if you have never seen one and never seen a cammer up close, you could easily confuse the two at first glance. The cammer is however HUGE in front due to all the space required to house the cam drive mechanisms. I wanted one for my 40, but it would probably take up the whole seating area and I would have to drive from the roof.
But now that the subject of short rods vs. long rods has been brought up, and please forgive me if I have missed this somewhere else, but I have been busy working on my other toy lately, I remember in the old days when I was foolish and played with motorcycles, there was an old trick called "short rodding" which was done with the 650cc Beezer and included as I recall
sawing off the tops of the cylinder barrels down to the third fin and installing the shorter 500cc rods. Changed the dynamics regarding the piston movement. ie. most of the piston movement took place in the first half of the combustion stroke in relation to the last half. This was a very quick machine. I rode it and almost killed myself, but that is another story. I understand the advantages of less side load and longevity, but what are the performance trade offs, if any? Thanks.

 

Hot Rod Magazine, of all things, had a great article about the pros and cons of each, and built a 350 chevy, utilizing a 400 block, short-stroke crank, and ford I-6 rods; very long rods- 6.3 inch vs stock 5.7- combined with a 3.25 inch stroke to produce a rod/stroke ratio of 1.9 vs stock 1.6-

In the article, they highlighted the merits of the long-rod setup- less sideloading, and the longer effective dwell at TDC during spark fire; The advocates suggested the optimum ratio was near 2:1.

However, they did point out that short-rod motors remain popular in some short-track racing circles, and despite the angularity of the rods, could make horsepower in a higher RPM range; the differences weren't dramatic, but pointed to two different tuning methods.... I'm sure that part of it may also simply be due to less mass from the smaller rods.

I forget the date of the article- I'm thinking June 1997-8, but not sure.

 

[Jim Glickenhaus]

Dear Chris
You do only live once. Congrats! What car are you putting this in? Your MKIII? Will you use it on the street? Can you get fuel for 12 to 1?
Best
Jim

 

Hi all

Yes, that Hot Rod article was the start of this idea. Increasing the rod length ratio closer to 2:1 improves combustion efficiency by extracting more power out of the same amount of fuel and air. This is because the piston position relative to the combustion chamber on the long rod engine takes longer to drop away from TDC on the combustion stroke.
By using long rods, the engine efficiency can be increased from around 30% to
35% — 40% delivered to the rear wheels.
Higher compression ratios can also be used because when combustion efficiency is improved, sensitivity to pre-detonation is simultaneously suppressed thus allowing the use of lower octane fuel than would normally be necessary. The higher compression also giving an increase in power and efficiency.
My 308 long rod will be the power behind my new MK1 GT40 I am going to use it as a track/hill climb car. I am making my own chassis and the new lightweight black impregnated body will be out of the mould in the next two weeks.

Regards

Chris

[ October 10, 2002: Message edited by: Chris Melia ]

 

[OMeyer]

Very interesting information. For my own edification I checked the figures on the FE engine series which basically used two rod lengths. The long rod was 6.54 inches and used in the early small displacement and short stroke FE motors (332, 352, and 361 CID). The short rod was 6.488 inches and used in the 390, 406, ,410, 427, 428. Crankshafts in these motors had strokes of 3.3 (332), 3.5 (352), 3.784 (390, 406, 427), and 3.984 (410 and 428). Ford must have been convinced at that time that the short rod combo was more effective as they shortened the rod when they lengthened the stroke. Analysis of these numbers shows that the stated theoretical optimum rod ratio of 2:1 was nearly acchieved in the 332 cu. in. engine which had a 1.98 ratio. The 352 enjoyed a 1.868, the 390-406-427 a 1.714, and the 410-428 a measly 1.628. Now, if all the theoretical figures discussed above are for real, imagine what the LeMans 427 Mk II cars would have been able to accomplish if they had been able to increase the volumetric efficiency from 30% to 35% or 40%. If 30% was 500 HP, then 35%-40% would have been closer to 600 HP. I wonder what they would have sounded like coming down the Mulsane at say 250 MPH with pieces of those little Ferraris hanging out of their mouths. Kind of makes you wonder... Anyway, back to reality. Are there any dyno numbers in the Hot Rod article to back this all up? If not, I guess we'll all have to wait for Chris to get some real "seat of the pants" data back to us.
Best regards,
Blue

 

[andys]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by BlueOvalBlood:
...Ford must have been convinced at that time that the short rod combo was more effective as they shortened the rod when they lengthened the stroke. Analysis of these numbers shows that the stated theoretical optimum rod ratio of 2:1 was nearly acchieved in the 332 cu. in. engine which had a 1.98 ratio. The 352 enjoyed a 1.868, the 390-406-427 a 1.714, and the 410-428 a measly 1.628. Now, if all the theoretical figures discussed above are for real, imagine what the LeMans 427 Mk II cars would have been able to accomplish if...
Best regards,
Blue<HR></BLOCKQUOTE>

Blue,

I'm going stricktly by memory here (dangerous territory I know, so I'll stand corrected), but wasn't the side-oiler a shorter stroke, longer rod, and larger bore than the std. FE? The bore to stroke ratio favored a higher RPM.

It always humored me when they beat Ferrari with that "good 'ol boy" NASCAR motor (though at the time, it made perfect sense when you think about it.). There are other equally interesting NASCAR vs. Le Mans and the Europeans titbits I'll share another time.

Andy

 

[OMeyer]

"I'm going stricktly by memory here (dangerous territory I know, so I'll stand corrected), but wasn't the side-oiler a shorter stroke, longer rod, and larger bore than the std. FE? The bore to stroke ratio favored a higher RPM."

Andy,
First off, by referring to the "side-oiler" you are including all 427s since they all, side oilers, center oilers, and cammers alike, shared the same bore, stroke, and rod length numbers. The bore size was 4.23, the stroke was 3.784, and the rod length was 6.488. (You may also note that in computing cubic inch displacement that the so called "427" was actually only 425 cubic inches. The reason Ford preferred the "427" designation is not certain, but I am sure that some of the other board members can expand upon this. BTW You will also note that in computing the cubic inch displacement of the so called "428" that it is actually only 427 cubic inches in displacement but obviously Ford couldn't name it as a "427" because they had already used that one up. See what a mess you can get yourself into down the road when at first you make up a little white lie?) The 427s in their various iterations used several different combinations of pistons, rods, and crankshafts, but all were the same in terms of the above dimensions. To answer your question, at 3.784 the stroke is neither the longest nor shortest of the FEs: ie. shorter than the 428 stroke of 3.984, but longer than the 3.30 of the 332 and the 3.50 of the 352. At 6.488 the rod length is the shorter of the two rod lengths used in the FE series. At 4.23 the bore size is the largest of all the FE series motors. So the answer to your question is definately a "qualified YES, NO, and YES". Hope this may answer some questions even though it probably gives rise to others. I wonder what rod ratio was used in those wicked little Ferrari motors...
Best regards,
Blue

 

The numbers on the long-rod engine were very impressive; 11:1 compression on 93 octane with no detonation, over 450 ft/lbs torque, with a very flat torque curve, and 400 hp; I suppose a tall-deck 302 block with the 3.0 stroke would work well with longer rods- I'm sure that some of the 5.0 tuners have explored this area.

 

[Mike Dozier]

My guess is that the 427 was so named because Mopar's big gun at the time was
a 426 engine and the Ford Marketing Dept
had to outdo Chrysler in advertised size.

MikeD