I'm sorry I misread his monicker. I transpose letters too at times. I hope I didn't offend you Dick.
Jose
Jose
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1966 Alpine Voted Best Of Class San Diego Miata Engine Swap ??
- Thread starter lastingimp
- Start date
John W
Bronze Level Sponsor
lastingimp
Donation Time
lastingimp is short for lasting impressions, perhaps your thought process needs realignment
lastingimp
Donation Time
thanks for your comments, as my car is very original i would rather now have the modern reliabilty of a newer engine and tranny, currently it takes 15 min to warm up and the travels down the freeway at 5,000 rpm while driving at 65 , would like to go 65 and turn 2500 rpm which you can not get with the normal sunbeam overdrive, since my car is in such good overall condition i just figured i do not need to have high horsepower, my sunbeam mechanic suggested the miata and he provided for me to test drive, smtty's sunbeams has been fixing sunbeams for over 20 years here in san diego, smitty is not money motivated as evidenced by his quote to do the job, howver we may still do the ford v6 if there are too many issues...lastingimp@aol.com which stands for lasting impressions one of my old companies...regards dick werby
lastingimp
Donation Time
thanks for your comments, as my car is very original i would rather now have the modern reliabilty of a newer engine and tranny, currently it takes 15 min to warm up and the travels down the freeway at 5,000 rpm while driving at 65 , would like to go 65 and turn 2500 rpm which you can not get with the normal sunbeam overdrive, since my car is in such good overall condition i just figured i do not need to have high horsepower, my sunbeam mechanic suggested the miata and he provided for me to test drive, smtty's sunbeams has been fixing sunbeams for over 20 years here in san diego, smitty is not money motivated as evidenced by his quote to do the job, however we may still do the ford v6 if there are too many issues...lastingimp@aol.com which stands for lasting impressions one of my old companies...regards dick werby
RootesRacer
Donation Time
The first thing I'll tell you is that either your speedo or your tach or both are lying to you.
Even with the 4.22 final ratio, 65mph will occur at 4400 RPM.
With the 3.89, it will occur at 4100 RPM.
While this still probably falls outside your desires, both are considerably off the 5000 figure.
An overdrive with the rootes 3.89 axle will net 3250 RPM at 65 in 4th OD.
Many have found this to be a very manageable RPM.
An axle swap may make a lot more sense than a full drive train swap, from what you have read above, it is rather unlikely that the miata engine itself will fit without chassis changes due to its height.
If you are happy with the sunbeam engine and performance, an axle swap may make a great deal more sense.
For instance a 2.73 (common 8 inch ford ratio) will run about 2850 RPM at 65mph. You will however loose a lot of acceleration due to the ratio change.
An axle would be a very reversible change to the car FYI.
Hope this helps.
Dick, if your turning 5 grand at 65, you need to put it in 4th. Seriously, the non overdrive Alpines do rev pretty high, but not that high. I'd say either your tach or speedo, probably both, need to be tuned up/calibrated. If I remember correctly "from the day" you should be seeing more like 4200 at 65.
Bill
Bill
RootesRacer
Donation Time
Keep in mind though that OD on a 3.89 yeilds 3.12 final ratio, with was used on some SIII alpines.
There are some that have used a 3.70 behind an OD which would be 2.96 final ratio.
The reason the factory didnt do this is becuase it hurts the sporty-ness of acceleration and the public could not be trusted not to lug the engine.
That said, I would not hesitate to go with a 3.89 + overdrive setup.
The 2.73 without OD is workable with the 8 or 8.5 inch clutch, but like I said acceleration is gonna hurt a bit (42% loss in torque all things the same).
I am in total agreement about the 3.89 with O.D., but direct 4th is what would make it doable.
My experience with the 3.55 ratio and the Ford 2.0 and 2.3 in the Alpine: It is kind of buzzy, but would be okay as a high gear. The 2 liter did not like to pull the 3.55 uphill while in 5th, (2.84 overall) unless I was going at least 70 mph. Just on the wrong side of the torque curve. I don't think I would go below 3.08. I think that all things considered, something in the 3.30 range would be the best compromise with a 4 speed.
Bill
lastingimp
Donation Time
thanks for comments even 4,200 rpm is too high for me, got spoiled with with 2006 jag xj8 i think 2250 at 70 on a 6 speed
RootesRacer
Donation Time
Well in general you arent going to have the kind of torque to do that on a little 4 banger.
Is not 3250 rpm at 65 acceptable?
alpine_64
Donation Time
The later arrow series cars had 3.70 diffs in some cases. Rootes NL was making new pinion sets in this ratio, a few members on the board bought them and installed (scott, ian, jan?).
As Jarrid stated 3.70 with OD would be quite tall at 2.96 which will have you somewhere around 2900-3100. With a strong stock 1725 it wont be much worse off the line either. I really think that is a good option for your car.
I cant see a miata engine/trans being that much better option if all you wanted was more comfortable highway cruising speeds.
Also as mentioned your speedo/tach seem way off.
One last thought, switching to 14" wheels with 70 series tyres (and appropriate width) or 15" wheels with 60 series tyres (and appropriate width) will also help on the cruise.
As Jarrid stated 3.70 with OD would be quite tall at 2.96 which will have you somewhere around 2900-3100. With a strong stock 1725 it wont be much worse off the line either. I really think that is a good option for your car.
I cant see a miata engine/trans being that much better option if all you wanted was more comfortable highway cruising speeds.
Also as mentioned your speedo/tach seem way off.
One last thought, switching to 14" wheels with 70 series tyres (and appropriate width) or 15" wheels with 60 series tyres (and appropriate width) will also help on the cruise.
If you are looking for 2500 @ 65, better have a long, long talk with Jose. He does not recommend gearing the 2.8 that tall. He says it likes to rev. His preferred gearing gives about 3100 @ 65.
Bill
65beam
Donation Time
swap
as i said ,the clutch would not last long if you did much stop and go. besides that we need to keep the rpm's up to oil the bearings. #3 rod bearings don't last long in these motors running 65mph and 25 lbs of oil pressure. i proved that on I26 a fews years ago. my series 4 with non OD and a 3:70 shows running about 3300 rpm. tiger tom calibrated my tach so it is very close. of course i never look at the tach when i'm driving.
as i said ,the clutch would not last long if you did much stop and go. besides that we need to keep the rpm's up to oil the bearings. #3 rod bearings don't last long in these motors running 65mph and 25 lbs of oil pressure. i proved that on I26 a fews years ago. my series 4 with non OD and a 3:70 shows running about 3300 rpm. tiger tom calibrated my tach so it is very close. of course i never look at the tach when i'm driving.
alpine_64
Donation Time
Bob,
So with 3.70 + OD im about right in that it would be 2900-3100?
I assume your car is still running 13" with high profiles? I think the 3.7 + OD and maybe a set of 14" with 185x70's would be about as high gearing as will be comfortable in an alpine engine. And i guess running around town or even up to 50ish MPH there would be no need to use 4th OD.. just direct or even 3rd OD.
Hi Lastingimp,
If you do go with the V6, you can use a gear set as tall as 3.55 (I used to suggest it for mild driving), but you will need to down shift to accelerate on the freeway. Also, you can´t drive under 60-65 mph. in fifth gear, because it will lug the engine. I was running 24" tall tires, and the engine would run at 2,000 rpm. at 55 mph. in fifth, which is lugging the little V6.
The stock Alpine rear end gearing (389), is just fine for the V6, since you aren´t looking for pure power and speed. You wouldn´t need to change out the rear end, thus saving you money too. For the most perfromance, I recommend using a lower gear set, like 4.11-4.22, which the V6 just loves.
Jose
If you do go with the V6, you can use a gear set as tall as 3.55 (I used to suggest it for mild driving), but you will need to down shift to accelerate on the freeway. Also, you can´t drive under 60-65 mph. in fifth gear, because it will lug the engine. I was running 24" tall tires, and the engine would run at 2,000 rpm. at 55 mph. in fifth, which is lugging the little V6.
The stock Alpine rear end gearing (389), is just fine for the V6, since you aren´t looking for pure power and speed. You wouldn´t need to change out the rear end, thus saving you money too. For the most perfromance, I recommend using a lower gear set, like 4.11-4.22, which the V6 just loves.
Jose
65beam
Donation Time
swap
michael,
i've been driving alpines without OD since the mid 60's. i have 175X80X13 on the cars. i had tiger tom rebuild my original trans and OD and he changed the ratio in the OD for the red harrington when i was putting it back together for the third time a few years ago. the OD has never been hooked up so i don't even know if it works. i have a couple more on the shelf. i hate the non syncro with a passion and if i ever get done with other cars it's going on the shelf. i don't drive the cars much so i don't really worry about what rpm's the cars are turning. after all i am not used to them running low rpm's plus there are no roads close to me that have a speed limit higher than 55. my choice is the 3:70 gears with non OD full syncro behind a 1725. that is the current setup in all of my cars except the red harrington.
michael,
i've been driving alpines without OD since the mid 60's. i have 175X80X13 on the cars. i had tiger tom rebuild my original trans and OD and he changed the ratio in the OD for the red harrington when i was putting it back together for the third time a few years ago. the OD has never been hooked up so i don't even know if it works. i have a couple more on the shelf. i hate the non syncro with a passion and if i ever get done with other cars it's going on the shelf. i don't drive the cars much so i don't really worry about what rpm's the cars are turning. after all i am not used to them running low rpm's plus there are no roads close to me that have a speed limit higher than 55. my choice is the 3:70 gears with non OD full syncro behind a 1725. that is the current setup in all of my cars except the red harrington.