1600 /4:12 vs 1776/3:88

Any pros and cons on the two options? I will spend some time on the highways although not a lot. Thanks

The 1776 with the 3:88 is much more relaxed on the freeway. This is the combo my car has. However the longevity of service life of the larger engine in it's "stock" mexican crate specification could be a concern. Keep the revs down and you will probably increase the life of the engine. My car keeps-up with traffic more than adequately with it's dual carbs and allows me to keep some distance from tailgaters.

Sorry I'm so lame but how is the 1600 cc increased to 1776cc. What is the Mexican thing? I figured it was just rebored or something!

Larger bores to the cylinders increase the displacement (and centrifugal load on the crank) despite the typically non counterweighted crank in the mexican crate motors. Unless you specify otherwise the motors that are provided in the base turnkey cars that are manufactured by Vintage Speedster (Kirk makes a very respectable product that is an outstanding value) are sourced by an outside builder. The warranty that is provided is very well supported by Vintage Speedster should there be any engine failure.

Gary,

I have a VS with a 3:88 R&P. I also had a taller gear set for 4th which allows for lower RPMs at speed. The plus is that it really makes highway, Freeway, and distance driving a breeze and holds down engine temps at highway speeds. The down side is you lose your hole shot (light to light) speeds to a noticable degree. So, unless your engine has enough power/torque, the 3:88 cuts into that aspect of driving pleasure. I have a built 1776 (probably around 95-100 hp)(not crate) and with the 3:88 I am able to muster a decent take off in 1st and 2nd, but nothing to write home about, but it comes alive in 3rd and 4th.

It comes down to expectations and driving habits.

Me? I would get a 2007cc or 2110 in a good solid mid level performance build and then run the 3:88. That's my plan anyway. I like my 1776, but would like more low end power with the 3:88.

69mm (crank) combined with a 85.5 bore (piston) equals 1584, aka 1600

69mm (crank) combined with a 90.5 bore (piston) equals 1776

I've noticed that Pat Downs seems to like the 78 x 94s, for a 2165. Anyone know why CB goes with this setup, rather that an 82 x 90.5 or 94? I realize that there is less clearancing with the 78. I wonder if the best long term motor would be a 78 x 90.5?
Ron

The 2007 (78x90.5) is an excellent combination in terms of longevity. Cima-brand 90.5mm barrels maintain the exact same wall thickness as the original 85.5mm best cooling whereas the 92mm barrels (same O.D as 90.5, but honed an additional 1.5mm for a thinner side wall) which could cause distortion & overheating.
On a side note, most forged cranks are now 78.4 size, which ups the capacity to a 2016cc rather than a 2007cc.

Gary, I like Jim have a "built" 1776. I would guess 95/105 HP. I have a 412 R&P. I bought this ratio to enhance exceleration. The 1776 doesn't have alot of low end. By gearing low I can keep up with cars that have a 2110 to about 60 mph. I go through 1st and 2nd very quickly, revving to 6000. Third is very good to pass with on curvy roads. It really blasts past semi's. Fourth gear is a little short for very long trips, but with a 1 1/2Q. sump and a remote cooler my oil temp is 180/210 on 100 plus degree days, up and down the mountains around here. If there is one draw back, the revs are a little high for noise comfort at speeds over 70mph. Speed in gears is 60mph/3000, 65mph/3250, 70mph/3500, 75mph/3750. Eddie PS I want a 2110 too!

A 76-mm, 78-mm, 78.4-mm, or 82-mm stroker with 90.5-mm or 94-mm bore combo will help tremendously with the 3.88 R&P since you will have more torque/hp to drive those gears. Turbo cars, for instance, like taller gears since the power/torque is there to drive the gearing.

CB Performance sells 76-mm, 78-mm, and 78.4-mm drop-in stroker kit combos with long rods to yield good connecting rod ratios.
Good luck,
Tony

Eddie, 3500 rpm at 70 doesn't sound too bad at all. I'm running a final drive ratio of 4.125 and a 0.82 top gear, with 185/60 x 15 tires (24.4 ") and my cruising rpm at 70 is around 3300 rpm. Heck, my 911 pickup, with its 901 5 speed, turns 3500/3600 rpm at 70, but then again, the redline is 7300.
Ron

Try this software to see what the theoretical speeds are at each rpm for given gearing.
www.actionimport.com/Tech_Files/gear_ratio_computer.htm

Very cool. It says that at 6000 rpm I should be able to do 129 mph. The question is, would the car still be on the road?
Ron

Ron, that speed is what shows on the speedo, the corrected speed is about 4mph slower. Eddie

Its really easy to "Overgear" a TI with a 3.88 R&P according to tire size and 4th gear ratio..

Many people think that RPM on the highway is a bad thing- Not so. This is not a newer watercooled car that is getting about 25% better cooling from its water cooled heads than we do with air cooling ours.

The RPM must be high enough on the highway to turn the cooling fan a decent RPM to generate cooling power. Also the load must be decreased to keep the engine from generating excess heat from the load.

By "Overgearing" the car the engine RPM is decreased and it feels more modern, BUT the load on the engine is increased thus making more heat, and when the engine tuen less RPM the fan turns slower!

The OIL TEMPS will be decreased by higher gearing BUT the HEAD TEMPS will be increased. Lower RPM = lower oil temps. You MUST worry about head temps 10 times more importantly as they vary so greatly in just a 5 minute timespan and are TOTALLY DEPENDANT UPON LOAD!!

The key is to gear the car according to the engines ability to shed heat, and the weight of the vehicle coupled with the tire sizes.

I have seen many cracked and melted heads from too tall of gearing (Freeway flier usually means hilltop death)

Buy instruments and wathc them, you will see what I'm referring to very quickly and hopefully before you melt something. In my opinion the manufacturers of these cars should be required to install a CHT gauge in every one as they leave the shop!!!Guys fry their heads and *THINK* that the temp gauge is also measuring head temps- NOT SO!

BTW This is one reason I LOVE a TIV engine, its almost impossible to "overgear" one using conventonal ratios

I heard this one before. You eather have to live with a higher RPM at crusie speed or chance the pully ratio on the fan pully's.

But yes with the proper test euipment in place you can trial and error the pully's into livable range with a assortment of overdrive pully's.
Then what if you discover variactions from head to head that would somehow have to be addressed to even the head temps out.

HOW is that usally corrected?

Good comment Jake. It's hard to always think in the aircooled world, having spent so much time in the watercooled world. All engines have an rpm range where they perform their best and are the most efficient. Anyone know what that range is for the Type 1?

Peak torque......Thate the point of highest efficiency, and least fuel use....More power with less energy being lost..

Pulley raios don't cut it all.....There is still load.. Load = heat in the heads.

Echoing Ron's comment.. thanks Jake. That was an eye opening post for a rookie aircooled person like me. I understand that head temps are something to be watched, but never realized that there could be such a difference between oil and head temps. What, in your opinion is an optimum RPM range for cooling your average built 1776 at highway speeds for longer hauls? Probably a dumb question, but..

Now would be a good time to mention head temperature guages. Jake has mentioned these on another forum and I think I'll buy one for my IM this spring. Jake recommends Westach. They have 2" CHT gauges with dual and quad senders. I like the dual model; one sender under the number 3 plug and one sender under the number 1 plug.
Ron

See Westach at: www.frostalarm.com/cat/p10.html

Jake, I am currently using a Raytek heat sensing gun to take head temps. I'm getting temps of 230-290 degrees taken after warm up, to stopping after a long steep grade. I have the numbers, I'm just not experienced enough to tell what range I should be in. Any help? Eddie

You need a core temp reading... Those heat guns take surface temp and are not accurate enough for readings.. By the time you stop the car and take reading the temps in the heads drop. Taking a reading at idle is not producing any load, so the temps are lower and not accurate. Head temps can drop 100 degrees in 30 seconds and rise just as fast!!!

It amazes me the depths guys go to just to keep from outfitting their car with full instrumentation. For the cost of a Raytek you can buy a VDO CHT gauge. Whiles ts not as fast reacting as westach its sure a way to monitor temps when you hit a hill....

If instrumentation was not important, aircraft cockpits would not have panels filled with them taking readings from every aspect of the beast.... In the aircraft community instruments keep Humans alvie, in VWS they keep engines alive- Buy them, watch them, learn from them.

Jake, thanks for setting me straight. The Raytek gun I'm using is free, I bought it for other uses, but even if it wasn't, I'm still not trying to avoid using proper instrumentation. I currently have an oil pressure, and oil temp gauge, and may soon have a head temp gauge. When someone with less knowledge than yourself asks for help a kind word never hurts, especially around engine buying time. Eddie

Eddie,
I wasn't trying to be mean or more harsh than needed toward you....

I have learned that people just don't understand the importance of some things unless they are told point blank.

I get emails in my inbox all the time with questions about temperatures and I sometimes get tired of teling the same old things over and over again, especially with those heat sensing thingamajiggers...

Sorry.

Jake, I understand, no sweat. Merry Christmas, Eddie

How would a 4:12 perform in a 1776, would it be quicker in the lower gears and without balls on the highway? How does the 3:88 change its performance?

Paul, I would describe it as ...The 4:12 will give you more "snap" off the line. If you have a stroker motor you may keep most of that snap because of the torque. A 3:88 with a 1776 will labor off the line ( not literally, but comparatively) ( you ain't going to burn much rubber) but picks up more passing "snap" at the higher speed range.
It really relates to rpm range, and where your power band for your particular motor is. A 4:12 will certainly do 70-80 mph, but the tach will read upwards of 4000 rpm, where the 3:88 will only read maybe 3200 rpm, which means you have more snap left in your power band for quicker passing. Each gear ratio serves a purpose depending on the type of driving you enjoy best.

What is the top speed of a 1776 motor, does it matter 4:12 or 3:88- I suspect your answer will be yes, the 4:12 will start faster but work harder at 70 than the other.

Tire size, carbs, cam, they all figure into it. Set yourself a reasonable RPM limit, go out on a deserted highway, and see for your self. Some guy with a mild 1776 might know pretty close,,,,I'm just guessing , but I would say 110, 115 is probably just about max generally. Seems fast enough with your butt that close to mother earth, and only 1/4 inch of fiberglass between you and eternity.

Top speed in these cars is kind of moot. I calculated that my 2110 would top out at just under 130 mph. I've had it up to just over 100 mph a few times, and believe me that was fast enough! I don't think that I will ever try and find out how close I can come to 130....getting chicken in my old age.
Ron

Paul... Ron & Gary have the flick. I've creeped mine around 90-95+ a couple of times but prudence and wanting to keep my 1776 intact until I go with a 2007/17 or 2110 plays in there! I think an IM would be a better platform for 90+ driving.

The true advantage of a 3:88 comes with more moderate freeway, highway, interstate cruising. Less work on the engine to accomplish the same thing with a 4:12. Per Jake I am putting on CHTs to monitor head temps, but I have to say I have been running 3 years and 19,000 miles with a 3:88 and a 1776cc at sustained 70-80 mph runs (more on the 70-75 side)and still have a nice tight running little 1776. That external oil cooler and fan do help, also the sump. I just ordered CHTs for this and any future engines though... so I can moniter head temps per Jakes advice. I guess the trick is to have a combo built that runs cool at the heads...

Back to high speed runs and the need for.... lets face it, unless you have a perfect road with little traffic, doing 100mph plus sustained (heavy on the sustained) is a high risk in most cars, especially a light Speedster Replica. My wife's Acura 3.2TL is built for interstate ass kicking, and still at 110-120 I am very wary... the car is better than the roads and the traffic I have to work through. I just sold a 3rd gen RX-7 Turbo, and past 125 there just wasn't a road out there worth dying on to see where she would peak. My point? Whether you go with a 4:12/3:88/3:44 your pick should be centered on where you want the max punch... and that takes a engine and R/P combo that meets that expectation. Also, forget high speed runs above 100+ in a pan car... unless you have a death wish. It can be done, but for how long? Think mid level punch... where you can REALLY use it, like side by side in traffic with that rice rocket and you want the juice to hit the gap.

ME? I like the 3:88, but would like an engine that pulls more torque on the low end.... just for grins at stoplights. Now at 2500-4500 Rpms in 3rd and 4th, my 1776 pushes nicely, but not as well as I want. When the time comes I will sit with a builder and explain what I am looking for and let them meet my needs.

So, for me a 2007/17 or 2110 built right, in a good daily driver mode, with a 3:88, oil-cooler and a good stable pan car may be the best bet short of popping the dough for an IM Speedster with a 901 and a nice 2110 or TIV. Someday I may do that... in the interim I'm keping my nice 1776 intact.

I'm no expert though... there are many on this net that can give you the tech why's and wht not's. I'm just a driver who works on his own car as much as I can, because that's half the fun.... Jim

Do not get me wrong, I do not want to go 100 mph on the NJ turnpike. Death would be the least of my worries. I will be checking out two roadsters this weekend (hopefully); one with a 2110 and the other with the IM super 90 (85 hp) to see which one I want to ask Henry to put in my new roadster in March. The new IM super 90 is a 1776 cc (100 hp) model. I was driving my Audi A6 2.7 biturbo (I mention this just to show what I am comparing to )yesterday on the highway and I was going between 65 and 75, and I enjoyed the kick it had to pass a highway speeds. I also like the get up and go in the lower gears., although my Audi is not fast off the start. I have read on other threads about people complaining about soccor moms in their Honda minivans blowing you away on the highway or off the line in the smaller engine replicas. It is supposed to be a sports car after all. I am asking what your experiance is. These questions may seem lame but buying a car like this is differenet. Normally you would go for a test drive. I do not have that luxury. Maybe this weekend I will get the chance.

Paul: My experience with my 2,110 is that I have a LOT of low and mid-range torque to play with (I have a 3.88 rear). Passing someone at 55 - 75 in forth is not a problem (it jumps), and passing granny's on back roads at 45+ in third is a real kick in the pants. Power is strong above 2,500 rpm and REALLY comes on strong over 4,100. I've read the other threads on 1776's and get the impression that they might be able to keep up, but would always have to be a gear lower to get the power they need for comparable acceleration. I had a "real" 1964 Super 90 years ago (110 hp) and remember how underpowered it always seemed to be, whereas this 2,110 has the power I always wished I had back then (and the "grin factor"). Gearing on mine gives me about 3,000 rpm just above 65mph - right where Jake tells us you get good cooling rpm on the fan - so it runs pretty cool at highway speeds. I have no idea what the top speed is (and, like others here, will never find out) but I've brushed up over 90 now and again and it's strong and stable there, too.
In your comparison this weekend, if the 2,110 is set up correctly I would be surprised if you didn't find it superior to the 1,776, but let us know what you find........cost and reliability is always a factor in these decisions..........

Good luck, Gordon

Paul, you may be satisfied with a 1776 now, but in a year or two you'll be looking for more power. I went the 1776 route and now have a 2110. Test driving both motors, back to back, should tell you what you need to know.
Ron

Ok, I just got back from my Long Island test drive...There is no question, the 2110cc is the one. Wow, neck snapping wow. The speedster I drove had had the 23110cc engine but no ac, and one single exhaust in the middle. It was, I think , quieter than the super 90. Nick, the owner of the roadster with the super 90, kept telling me for the whole drive how much he liked the bigger engine. When I drove both, I see why. Again, even though Nick had ac, he never used it. Both cars had electric windows and that was a nice option. One had leather and one had leatherette (vinyl), and there was not that much difference., this may be an area of cost savings I can use to get the bigger engine. I was thinking of not getting the rear disc brakes but after driving the 2110cc, you need all of the brakes you can get. Courtesy lights are a must. Heated seats were also nice. One thing I did not like was the location of the emergency brake. Does anyone know how much Henry charges to install the unbrella brake. All in all, I was impressed...

Don't know the exact price but it isn't very much I think 250 or less