1900-2050cc engine: Should I go Type I or Type IV??

I know, I know.... this question will end in tears.

I am genuinely finding it difficult to decide whether to go the type I or type IV route for an upgraded engine for my car.

I built my car with an almost stock Type I unit to get me started (ok, its 1641cc and has a SCAT C25 cam and kadrons). It also has a strengthened (IRS) gearbox with 0.93 4th gear / 3.44 final drive in anticipation of a bigger power unit. I'd build the new engine in parallel to running the car with the existing one.

At the 1900-2050cc capacity (say 90-100 bhp) can the hastle (and expense?) of switching to Type 4 power be justified?

My thoughts at this time are either:

Type IV: rebuild 1800 unit with keith black 96mm kit for 1911cc
Type I: 74 or 76 x 90.5 for 1914cc or 1955cc

At the moment i'm leaning towards the type IV, but i'm not sure why!

If you are going to put more than just weekend rides in the country miles on it I'd go for the TIV. I'd be leary of using a 35 year old used T1 case for that large an engine - so you'd be faced with a new case, an expensive stroker crank, big valve heads and expensive case machining. None needed with the TIV. A 2.0L (if you can get one reasonable) or 1.7/1.8L TIV is a good strong basis. Seems in reading some of the TIV forums that the 1.7/1.8 with the 2.0L crank and rods is the way to go - even with 94mm P&C. I see no differences in the 1.7 or 1.8 as a base core - is there advantage of one over another if you are replacing the P&C anyway? I like the stock oil filter and other more modern features of the TIV (ha, only a 20-25 year old engine). If you built you last engine (are mechanically inclined)- you can save $ by doing the Joe Cali conversion using the old time along with T1 tin -- saving ~$450 for a fibergass shroud. I just bought a 1.8 75 TIV and am pondering the same ? you have. When I add up all the costs --- gulp.

Simon: What kind of driving are you going to do with the car?
How much do you want to spend?
The cheapest and quickest route would be to wait until winter, pull your motor, boar your existing case for 94mm pistons get some new heads and a cam. A 1914 should give you 90 hp easy. Depending on what you want to do with the car though this may not be the best answer.

Your final drive seems low. It is about the same as mine but I have low profile tires, which end up giving me near stock gearing. You may find you run hot at highway speeds since the engine fan is not turning over that quick.

Do you plan on running heat? And how do you plan to do it?

Its all in what you want.

I'll be the first to say the a TIV is not for everyone..

The gearing you have will not compliment most TI engines, but a torquey TIV will love it. The gearing combo is a tad odd, but thats a super strong R&P!

The TIV will not make as much violent power, but will be the ultimate in smoothness and reliability. It will cruise at any speed you wish to put the speedomer and hold it for hours on end much better than a TI. The TIV you are contemplating is barely modified, just 2mm more bore than stock.... The TI at 1914cc has 8.5mm more bore than stock, huge difference.

Its ultimately a huge decision, but knowing what I know, and building both engines I would not even blink to build the 1911! It would happen so fast you'd swear that it was "miracled" together!

The 1911 is a great combo, and I have 8 or so recipes for one. I'm starting to offer them again since they are the most economical TIV to build.

TIs are for zero-60, TIVs are for 50-120!

Gregory, Keep track of the time it takes to do your Cali style conversion.... The DTM takes 2-3 hours to install and enables the engine to be raised to any size in the future without stepping up to another system.. Since August I have sold 15 DTMs to guys that "Ha" the Cali set up. Its always great just to get another convert on the road no matter how its done, but the ultimate in simplicity and practicality is worth the money, ask anyone who has one...

Simon: Also something to consider - the Euro is strong against the dollar right now - might make Jake's T-4 even more attractive!!

Simon
If the piggy bank can handle it go for a Raby T -4
if not, I'll suggest a T-1 1914
I had one in a kit car 6 years ago.... what a deep torque pulling ride that was and stll got 30 mpg with the Delloro's ..check with Jake for facts and more info Alan M

Thanks all for your responses so far.

Gregory - I think the only advantages of the 1.8 (over the 1.7) are bigger valves ('74 year) and not needing to machine the head for the bigger barrels. Re the shroud, I love the look of the DTM so want to go that route $$$ permitting, but a cheaper option here in Europe is (and I think similar to the cali conversion) a kit to allow type 1 tinware/fan to be used.

www.csp-shop.de/shop2/frame_nachladen.php?func=anzeige&wkid=2403651526&rub1=Engine&rub2=Type-4+Cooling+Systems&pn=0

Bruce - Swapping out the Pistons & barrels is my low budget fallback, though i'd still need bigger carbs and to convert to full flow/oil filter somehow. Not sure how my existing bored case and other internals would cope (long block rebuilt in South Africa at an old VW plant now operated by REMTEC).

The 3.44 R&P / 0.93 4th is a reasonable common high-ratio option here as it narrows the gap between 3rd and 4th (1-3 stay standard). Ideally, I do need more torque than my current 1641 unit though, for fast getaways... and am careful not to lug around town.

Steven - for heat i'm happy to plan for a webasto/eberspacer gas heater in the future; the current heat is pretty poor anyway, and the small petrol unit would fit up front quite easily.

Gordon - your right about the dollar; shame that i've also got US investments offseting the advantage !!!

[deep breath!]

Jake - I do plan to get hold of a DTM shroud if I go type 4 (just noticed aircooled.net will ship to UK), and would love to buy one of your engines if I can afford one and it makes sense. I must admit i thought my requirements were too tame for your services :))

A quick calculation reveals that to have a longblock built here and complete to turnkey myself (reusing my vac unilite, hyfire 6, alternator/fan assembly) with DTM, riechert exhaust, twin webers would cost in excess of

Simon, pleaseemailme instead of talking $$$ here. While I'm here I try to separate money and chat..

All I can say is that while the dollar is so weak, its a prime time to buy in the UK!

BTW, the TIV makes so much torque that a gear drop that is felt in a TIO application feels stock to a TIV engine.... I have ran cars with a 3.88 and a .75 4th gear that cruise like animals and handle the drop from a 1.26 3rd gear great.

Jake - You have mail....

Has anyone tried installing a TIV into a Speedster without converting it to upright? Seems the extra 6 inches is available in the engine bay. My CMC even has a rear steel piece that could be used for the rear mount for extra support (like the Porsche 914 had in the front of the engine). Granted changing the fan belt might be a weekend job but you'd save the conversion to upright, keep factory proven tin and even the FI if desired or a center mounted carb.

Not going upright gives many challenges, and negative effects. The engine might fit but the cooling fan sits in a very restrictive area if installed in any other car than a bus/411/412 or a 914 they were made for them.

The other issue is working on it. The stock system is not fun to work with, especially the alternator.

It is also heavy, the upright systems knock 45-50 pounds off the engine and cool better than stock.. I'm sure it could be made to fit, but would not be pretty or functional.

Decision made and piggy bank emptied :)

I decided to go the whole hog and will be fitting a 2270cc T4. I didn't want to upgrade once only to upgrade again in a couple of years.

Just got to hope that the UK summer won't be over (if it even begins!) by the time it arrives

oops, wrong button,big fat fingers and a crappy little laptop, no that's too severe, a 'sensitive' little laptop... good luck Simon, Good Choice, I think that is one that Bob Barker got.

Had heard that the OEM 1.8L cylinders can be bored out to 96MM (from 94MM) and that result was better than the new "aftermarket) 96MM combined sets. Are 2L pistons then used and if so do they fit with stock crank/rods or is skirt machining req'd?

Its not just hearsay, its thr truth. All my cylinders are bored originals in 96mm.. The new ones are pure junk.

Simon, glad you made the step up to RAT power, I'm sure you'll love what I creat for ya!

George, I have a RAT 2270 with a DTM thats for my CMC Flare. There is no real issue regarding the space. It fits perect. Though I did pull it back out and place it into it crate. I am in the process of fabing up a custom frame . The the RAT Motor sits patiently in its temple (Crate) awaiting the future union with my finished project.I would say it was worth every penny. I did flip for the trans to match. Jake did you get my long over due paper work?It was one of those things were the wife filed it. Question Jake - whats you opinion on forced air induction and airboxes for the 2270? I have fabricated ducts into the flares to aid in drawning clean cooler air to the carbs. There will be an exit opening in the rear deck to continue the air flow.
Later,
Joe