engine overhaul

[david langford]

Hi Guys
          Getting the heads converted to run on unleaded, probably at the end of summer and while they're off I was going to replace the exhaust manifolds to stainless steel ones. Any idea on what would be the best ones to go for?
           Is it also worth changing the inlet manifold and carb, aswell? Got an Autolite on there at the moment and have heard they're not the greatest.
           Any advice would be appreciated.
                  Dave

[shep]

Hi David, Where to start? You will find it difficult to find off-the-shelf exhaust manifolds in stainless. We have modified 428 Mustang headers, but it is better to have them made them from scratch. Yes, put the Autolite carb and cast iron manifold on a very strong shelf in your garage (just for originality one day) and fit an aluminium intake and Holley carb. It will save 25 kgs and perform much better in every way. A decent electric radiator fan sucking from the engine side, and an oil cooler should help with temperature. While you are at it, the coil and distributor can be changed to Mallory either with or without points. Big Al' at Thunder Road Speed Shop in Woking has done the job so many times, it would be daft not to ask his advice. Being honest, I think the auto box is better than going manual, and the handling can be vastly improved with stiffer springs, adjustable shocks and fitting anti-roll bars. Complete the package with Avon Turbospeed tyres (off the Bentley Turbo R) on 8.5 x 15 inch wire wheels. Bingo, you'll love it, and everything is reversible if you want to sell it in 10 years time for 250k! Good luck, Andy. PS you missed a great night out at the AC Owners Club Dinner Dance last Saturday. Maybe next year?

[J Jones]

Amen, Andy - on almost everything.
   
   I replaced my original auto box with a Tremec 5-speed. My original reason for swapping transmissions was due to the extreme heat generated by the Police interceptor C-6 box. In half an hour of driving (in California), you could have cooked an egg on the trans cover. Ouch!
   The manual is smaller in size and more efficient. It generates less heat, and the heat it does generate is carried away by better airflow through the transmission tunnel. The swap is easy  (at least it was on my car) as the mounting points are already in place, and no chassis alteration is needed to install a top-loader based manual. It's an easily reversible swap. I've kept the original transmission and torque converter, as I have done for everthing I've replaced on my car.(except the radiator and flex-fan. I threw them out in a fit of garage cleaning. And the diff gears - They went into Mr. Feldman's coupe when I changed the rear-end ratio on my car)
   
   If you plan on driving in hilly or twisty terrain, a manual gives you better control. You get better mileage, better acceleration, a higher top speed and lower revs. Torque is still your friend!
   
   I know it's been said (for years) that 428's are best suited to auto boxes. That might be true if you were to use a modern automatic transmission, but the original, though tough and bullet-proof, is a major source of heat and a waste of power.
   
   Amen, as well, to changing the intake manifold, the heads, the exhaust manifold, the radiator, the fan, springs, shocks - all that Andy suggests and more.
   
   A wonderful thing about the engine and drivetrain is: You can still get EVERYTHING you need - inexpensively! - to shed weight and improve performance! I replaced my iron Intake manifold with the identical date-correct aluminum Police Interceptor manifold, saving (as Andy says) a great deal of weight! I re-purposed my transmission oil cooler to an engine oil cooler, and the difference in consistant running temperature is considerable. Modern Aluminum heads (I used Edelbrock) solve the valve seat problem, save weight, improve performance and engine heat dispersal. A small chin spoiler (nearly invisible, and removeable) also helps enormously.
   
   David - you can easily purchase a "correct" Holley 4 barrel on Ebay (requires time and patience), or buy one a new one. Not only are they still being produced, they also re-condition the old stuff.
   Edelbrock, Blue Thunder (and others) make correct aluminum intakes, if you don't care to track down an "original".
   Exhaust headers are a custom-fit proposition. As Andy says; nothing will fit without modification. Not a big problem, but it does require an artful professional to be successful visually and functionally. I replaced the whole exhaust system with ceramic coated stainless. Now much more heat goes out the tailpipes, less on the passengers bums.

[shep]

Hi Jeff, I feel like I have just joined one of those "Born Again" churches! We are both singing the same hymns. I do agree with you on the Tremec 5 speed. I converted mine to a 4 speed original Top Loader, which is slow and clunky, and excepting the clutch slip, I could use 3rd and 4th for everything. I'm sure yours is a different story. My clutch is a bit on the heavy side, and overall I hate to say it, but I prefer the auto for the character of the car.
   
   I must admit I agree with the extra control the manual gives you. I raced mine at the Bentley Drivers' Club Meeting at Silverstone a couple of times with the auto box, and would have killed for a manual. But every day, I could live with the auto.
   
   You are right too about the Ali Heads. By the time David has had his iron heads machined and the hard valve seats fitted, it may be cheaper to fit new heads which are much lighter, breathe better and don't hold so much heat.
   
   The trouble is, things are so much better now, and a re-engineered car is so much more pleasant to drive. There are people re-engineering Jaguars and Austin Healeys which are lovely and reliable. Just keep all the parts you replace, so one day they are there for the one who wants to go "au Naturelle"
   
   Great fun, and good to hear from you, All the best, Andy.

[david langford]

Hi Andy and Jeff
                   I plan to do all the things you suggest but one thing at a time, alas. Last year it was the interior, so nice to get into a car with carpets. Put plenty of insulation in aswell so hope not to cook this summer. This year it's going to be engine.
                   Hadn't thought about ali heads. Could go that way and leave the exhaust manifolds for a later time. My thinking being if I get the engine up to scratch, the ancilleries can be done as and when.
                   Not fussed about originality, just want the car to be good and useable, so modern intake and carb it is. Edelbrock seem to do everything I need, including the heads. Fans will be replaced. Got the original? twin Smiths ones and guessing you can get better ones now.
                   Had assumed the oil cooler did the engine, what with all the overheating problems A.C. had with the car. Will see how the temp gauge behaves after I've had all these things done.
                   I do remember speaking to Andy about going manual when I first got the car(many years ago)and even then he said the auto suited the car best. At the time I thought he was mad, but, now, I have to say I agree with him. Mind you, that could change when I get the suspension done. Could even change when I get the engine done.
                  Thanks for your advice, no doubt I'll be back on here again asking more inane questions.
                      Dave

[J Jones]

Emmanuel is in the process of putting his car back together, and he has decided to do something that has been talked about  on the forum.
   Mike McCluskey is fabricating two fan-assisted ducts to push engine compartment heat out the side-vents. It will be interesting to see if this will make those vents actually do something. (I think it will)
   There'll be dancin' in the aisles of the church of the born-again 428 if it works! Halleluja!

[cliffordl]

I think Thunder Road have already done the fan duct option for a car that spends much of its time on the Spanish border. Incorporates small fans to push the air through and apparently works well.

[Emmanueld]

Hi guys, to me, manual and 5 speed is the way to go, makes the car drive like a cobra. First I improved the engine with the stock automatic, then I installed a Toploader, did not like the shifting, my mechanic had advised against the Hurst shifter and I think he was right. I then installed the TKO 600 with a .80 fifth gear. Made a huge difference. Incidentally, the Tremec TKO has a neat feature which makes installation very easy, you can move the shifter 5 different locations and you can buy it with a Ford bolt pattern and spline. In other words, you get a Ford FE and Toploader belhousing and its bolt on. On Jeffrey's car which has a metal center tunnel cover a slight modification was needed, on my car which has a fiberglass tunnel, no modification was needed. Previously,  I had changed the final ratio to factory specs with the Toploader. It's now too long and the differential is now being converted to 3.31 like Jeffrey. Of course the motor in my car is huge, it's a stroked side oiler 454 cubes with solid lifters.The car has massive torque and will rev to 7,000 if needed, but its perfectly civilized in traffic. Incidentally, I used a McLeod clutch, it's a patented system which increase grab as HP goes up, the result is very light clutch for the street.
   
   The car is still comfortable but is now fun to drive and can go on all day long at a very high rate of speed. The combined stiffer shocks and springs and 6" longer wheelbase makes for a stable and fine handling automobile which feels much more modern than it is. The car has been painted, now we are doing the boot, engine compartment and chassis, all suspensions and steering components have been removed, It is being bolted to a "rotisserie" to paint the chassis and undercarriage.  We will start the final re-assembly process shortly and it should be back together by end of summer. I know AC intended a luxury car, but really it's not, it's really a fine sports car when properly setup, it will easily outperform anything from the 60's and the 70's.
   E[:)]

[Gus Meyjes]

Just don't use the mcLeod throwout bearing... I replaced two and went back to the mechanical linkage. Maybe they got better in the past 5 years, but there were some serious problems with the seals.