1600 xflow with 1300 internals

[Dum_Bass]

hey people just another random post, i have heard of people putting 1300 crank, rods & pistons into a 1600 xflow block. i was just wondering what are the advantages of doing this kind of set up? do you get a more revvy engine? do you get any more power from doing this? the only reason i would like to know is because i have some 1300 rods and a crank laying around, although i dont have any 1300 pistons but i do have some 1600 +0.020 pistons pocketed to take kent 244 cam if these would be any good, and i need to get my engine sorted for next month.

[Graham]

you cant use 1300 rods in a 1600 they are too short.

1300 pistons are good in a 1600 because they raise the compression a ratio, like wise 1100 pistons giver higher cr in a 1300.

if you put 1300 crank with 1600 rods in a 1600 block you will get a power gain and freer reving engine compaired to all 1300 bits , this is because the angle through which the rods push against the crank is reduced so internal engine friction is reduced, also the longer rod causes the piston to take longer to go over TDC, this improves cylinder filling on any engine which has a restrictive head and port arrangement, which is just about every two valve engine ever built.

so if you wanted to build a hot 1300 on a tight budget the best way to go is
1300 crank
1100 pistons
1600 rods and block.

a 244 cam is quite hot in a 1600, and very hot in a 1300.

both 1300 and 1600 will benifit from having lightened flywheels the oe ones are very heavy

if you want to liven a 1600 up and make it freer reving you can buy long rods but your talking expensive steel ones, and not worth doing until you have a very special engine, but if you can find a set fitting a set of flat top twin cam pistons is well worth doing, they are much lighter than x/flow so the engine will rev better, but you will need to get a bit machined off the top of them or your compression will be miles too high

[Dave]

.........

[Dum_Bass]

Thanks for the info, its given me something to think about. if i were to build a hot 1300 with a 1300 crank, 1100 pistons, 1600 rods and block and also a kent 244 cam would i need to get the pistons machined still? probably a silly question really, sorry i just dont really have a clue and its all bits that i have laying around and would love to use. what sort of power would i be looking at roughly with a standard 1600 head?

[SidewaysMk1]

if u want long rods you can use datsun L16 rods 133mm rod compared to 125.25(1600 xflow rod). think 60 thou datsun bearings are needed to work the rods ona ford crank.

[Graham]

Thanks for the info, its given me something to think about. if i were to build a hot 1300 with a 1300 crank, 1100 pistons, 1600 rods and block and also a kent 244 cam would i need to get the pistons machined still? probably a silly question really, sorry i just dont really have a clue and its all bits that i have laying around and would love to use. what sort of power would i be looking at roughly with a standard 1600 head?

unless you use twin cam pistons anything fitted with a 244 cam would need piston mods.

assuming its a road car its really not worth trying to build a hot 1300, you will get lots more power and torque from a 1600

more than anything else the x/flow needs two things to make good power, a cam and a modified head. but if the budget wont stretch to both, get your pistons machined and fit a cam, its easy to change the head later on.

if you dont want to modify pistons a BCF2 or A2 cam should be ok but you must always do a valve to piston clearance check.

[magic55]

Graham.
You seem to be a man in the know, so...
im about to build a hot 1300 for road use (insurance reasons ).
1100 pistons, 234 cam Big valve head etc and throttle body fuel injection once its on the road.
The intention is then to eventually transfer the top end onto a 1760 bottom end.

How much of an advantage is there building a 1300 in a 1600 block? in terms of performance and drivability?

cheers

[Graham]

Graham.
You seem to be a man in the know, so...
im about to build a hot 1300 for road use (insurance reasons ).
1100 pistons, 234 cam Big valve head etc and throttle body fuel injection once its on the road.
The intention is then to eventually transfer the top end onto a 1760 bottom end.

How much of an advantage is there building a 1300 in a 1600 block? in terms of performance and drivability?

cheers

i've been wondering why every one is on about building 1300's.

building it into a 1600 block has the following downsides, A, its a bit heavier, B, it looks like a 1600!

it does help with power and make th e engine a bit freer reving, but only really at the top end and even then the engine wants to be a high spec one to really make it worth while,

if you can cheaply and easily do it then i would say go for it, otherwise stick with all 1300 bits, my mates 10,000 rpm 140bhp 1300 didn't have any 1600 bits (rule book you see)

[Lee S]

Magic it seems like you want to go legit with the insurance. To be honest chances are you will get quoted less for a standard 1600 than a modded 1300 thats making the same power (with alot less torque)

Another thing too, spending all this money on getting the 1300 to go like a 1600, you could probably spend it on the insurance for a 1600 (If it was to be any more)

[petrolhead]

If you put 1300 internals (crank, rods and pistons) in a 1600 block you'll get a 1300cc displacement but a very low compression. The stroke remains the same as a 1300 but the 1600 is taller so you will end up with a very large squish area and therefore very low compression. I can only imagine this would be useful for forced induction.

[Graham]

If you put 1300 internals (crank, rods and pistons) in a 1600 block you'll get a 1300cc displacement but a very low compression. The stroke remains the same as a 1300 but the 1600 is taller so you will end up with a very large squish area and therefore very low compression. I can only imagine this would be useful for forced induction.

yes but thats not how you do it,

you use the longer 1600 rod as well, the longer rod offsetting the taller block, in fact the long rod is the reason why the conversion works as it reduces the angle the rod moves through which redues internal friction and improves cylinder filling by allowing the piston to dwell at tdc for longer

[magic55]

I know that it will be cheaper for a standard 1600 but id rather have a tuned 1300 than a bog standard 1600. Half the fun for me if having an engine that i can build then modify/tune once its up and running.
and it's more unusual. id only want to tune the 1600 anyway
Id rather spend my time building a car than driving it.

I think ill go with 1300 bits as it seems the best option, and i don't have any 1600 bits!

[Graham]

makes sense magic, if you were using A6/A8 254/264 cams then it would be more worth while looking at a hybrid,

one of the best things about 1300's is the rev well anyway and are almost indestructable, my mates 10,000 rpm engine was on a std crank and modified std rods, the only steel bits were the front pulley and rocker posts

[magic55]

Wow! 10k rpm on standard bits. thats pretty amazing
did it last long between breaking/rebuilds?

[Graham]

it was a rally car, so it used to last quite well, it did eventually throw a rod, but still finished the rally despite only 3 cyls and a hole in the side of the block! infact i've still got the remaining 3 rods, they were lightened polished and truftrided and fitted with heavier duty bolts, but were still std ford rods none the less.

somewhere in my collection of old books is one on barry lee when he was a new boy on the block in the hot rods and how he came 2nd to george polley who had a 1650 x/f in his anglia , barry lee had a borrowed std bottom ended 1300 that they dare not blow up, apart from having to change gear 4 times a lap ( hot rods only use 1 gear once on the move) he said how they were reving that to 10,000

[petrolhead]

Apologies Grayham, I missed the 1600 rods, serves me right for skim reading. That makes sense, the weight penalty of using a 1600 block should only be about 5kilos. I have an ancient book on tuning crossflows by Vizard from back in the day. He states that getting a 1100 Xflow to rev to over 10,000 is possible on mostly stock parts, the stroke/bore ratio is so oversquare it is more like a motorbike engine.

If it is for insurance purposes I would also stick with a 1600, you can get 110bhp out of a 1600 that looks externally indistinguishable (spelling?) from standard. It would be more cost effective.

regards,

Petrolhead Matt

[dannyboymk2]

http://pumaracing.co.uk/cflow.htm

May be of some help to people. I've certainly found it useful, its a bit of a long read but goes along the similar lines as this thread (well for the 1600 people anyway)

HTH

[revnrich]

If the 1300 crank doesnt bring the rod and piston as high in the block how is a 1600 rod and any factory piston going to reach the deck?? by my calculations it would be 7.315mm lower than deck which would make the datsun 133mm rod an excellent choice.

[RWD fords rule]

Using a 1300 crank, 1600 block, + 1600 rods and 1100 pistons would not work, the compression height would be too low as you would be effectively de stroking a 1600 bottom end, so the pistons wouldn't come anywhere near the top of the block @ tdc unless you used rods a lot longer than std 1600 rods.

I think the best combination would be to use a 1300 block, with 1300 crank, and aftermarket rods or maybe datsun rods and shorter slipper pistons, there's no real point in using a 1600 block, I would aim for a rod to stroke ratio of 1.7 to 1.8 to 1 so that would mean 107.1mm to 113.4mm long rods and custom forged pistons to suit.

Std 1600 rods are 125.2 mm long, with a 1300 crank that give a rod ratio of 1.987 to 1, which in my opinion is too much, shorter rods as above and short slipper pistons in a 1300block would be a far lighter and also stronger combination due to the lighter pistons, that setup would reliably take 10,000 maybe even 11,000

Regards
Jason

[revnrich]

I think using a 1600 block has some advantages. The kent engine especially the low deck has issues with the distributer clashing with intake manifolding usually its a comprimise. I have managed to lower a motorcraft dizzy about 20mm with side exit cap leaves just enough room for a set of keihin bike carbs while keeping strut tower clearance. I agree with your comments as the longer rod has advantages but leads to a heavier reciprecating mass, but also the longer rod tends to have more dwell at tdc which will always help with this type of combustion chamber. Now just to throw a spanner in the works how about a 1500 crank or l16 datsun crank in a 1600 block long rod with short piston, this combo may be near ideal rod/stroke ratio and decent dwell- what do you think?
Ive just put together a 1600 block with L18 datsun crank offset ground by 1mm giving a stroke of 78.62 using datsun 130mm rods and shortened 60thou over 1300 pistons
I am yet to have this engine running but should be a goodie- go the modifyed kent engine.

[Kee]

use 1100 rods in a 1300 as they are 4.85mm longer than the 1300 rods and apparently stronger too
you could then use 1600 pistons and machine them to down to fit the deck height and also set your own CR. The piston would then be much lighter.

I'll be doing a pre x/flow conversion next year on my 1300 and using 1100 rods and skimmed flat top pistons.

[ebenech]

Hi you all mates. I've been reading very carefully this very interesting thread, and a question (silly maybe), came to my thinkings. Here we go:

I have an extra xflow engine sleeping in my place. This engine have been fully overhauled and only have runned 2000 miles just to see that everyhting was fine. The specs are: 1700 "big bore" w/1300 pistons to better CR, stage 2 head, (vulcain engineering), w/big valves, 285 piper cam kit, fly wheel lightened, fully balanced, 32/36 carb, etc. Well, the engines is really good, as are the other three I have installed in my MK2s. OK, and here comes my silly question, what will happen if I swap the crank it has (1600), for a 1300, leaviing all the other stuff as it is. Is that swap possible ? If it is, what gain will I obtain, more HP, higher revs, both ?

Oh well, allways thinking of things to do to improve my engines, and also to mantain my brain busy

OK m8s, now I remain waiting that the answers come rolling.

Cheers,

Eduardo

[Graham]

if you swap a 1600 crank for a 1300 your engine will be a lot less powerfull because not only will it loose 300 odd cc it will drop a ratio on the compression

[ebenech]

if you swap a 1600 crank for a 1300 your engine will be a lot less powerfull because not only will it loose 300 odd cc it will drop a ratio on the compression

Thanks a lot Graham Let's start thinking in something else to do with my engine. Told you, my question was silly.

[revnrich]

Hey the only reason to build a 1300 from a 1600 block is to gain a longer rod and more clearance for manifolding, a 1600 will always make more power. I think the idea behind building an engine like this would be ecomonmy and efficiency. Better bore stroke ratio, more dwell at tdc, less anglarity of the conrod and more efficient manifolding. The trick to this combo is keeping the reciprocating mass down otherwise you are probably loosing out. Install some aftermarket lightweight L16 133mm conrods and light pistons you could allways remove some deck height to make it work better. coincidently im building a chrysler 400 truck block which is a low deck and using a 440 crank from a high deck motor, this is the other way round to what we are talking about here, but the 440 bigblock is really too tall for an engine under 500 cubes. With this conversion you use a lighter piston with a smaller gudgeon height and the 440 rods. Advantages are lighter piston, shorter pushrods and a better bore stroke ratio as the 400 runs a bigger bore.

Maybe this set up would be ideal for a 1300 turbo conversion???

[POO SLINGER]

if you are using a 1300 for insurance reasons but using a 1600 block is that not defeating the object as insurance companys often ask for engine block numbers on modified classics?

[ebenech]

you cant use 1300 rods in a 1600 they are too short.

1300 pistons are good in a 1600 because they raise the compression a ratio, like wise 1100 pistons giver higher cr in a 1300.

if you put 1300 crank with 1600 rods in a 1600 block you will get a power gain and freer reving engine compaired to all 1300 bits , this is because the angle through which the rods push against the crank is reduced so internal engine friction is reduced, also the longer rod causes the piston to take longer to go over TDC, this improves cylinder filling on any engine which has a restrictive head and port arrangement, which is just about every two valve engine ever built.

so if you wanted to build a hot 1300 on a tight budget the best way to go is
1300 crank
1100 pistons
1600 rods and block.

a 244 cam is quite hot in a 1600, and very hot in a 1300.

both 1300 and 1600 will benifit from having lightened flywheels the oe ones are very heavy

if you want to liven a 1600 up and make it freer reving you can buy long rods but your talking expensive steel ones, and not worth doing until you have a very special engine, but if you can find a set fitting a set of flat top twin cam pistons is well worth doing, they are much lighter than x/flow so the engine will rev better, but you will need to get a bit machined off the top of them or your compression will be miles too high

Hi Graham, sorry for coming again on my subject, but isn't it this what I was asking in my post ? Maybe I have to put longer rods, is that it ?

Let me have your advise

Eduardo

[ebenech]

yes but thats not how you do it,

you use the longer 1600 rod as well, the longer rod offsetting the taller block, in fact the long rod is the reason why the conversion works as it reduces the angle the rod moves through which redues internal friction and improves cylinder filling by allowing the piston to dwell at tdc for longer

Same thing here Graham ?

Eduardo

[Kee]

you'll need the long rods to use a 1300 crank or use long datsun rods, whatever they are.

[ebenech]

you'll need the long rods to use a 1300 crank or use long datsun rods, whatever they are.

Hi Lee, thanks for answering. When you mean the long rods, your are saying the standard 1600 rods, (4.93"), or the extra long (5.23"), as it says in Burton Catalog. If it's the extra long, will they fit in my oversize 1300 pistons, (.090) ? Which is the lenght of the long Datsun rods ?

Sorry for so many questions, but will help to see if I keep going with this project.

Cheers,

Eduardo.

PS. One more basic question, is it worth while to try to do this to my engine ? Will i gain something, i.e. power or revs, or both ?

[ebenech]

Sorry Kee for mi mistake with your name, It was not in purpose, but it's not friendly.

My apologies

Eduardo

[revnrich]

Hello the datsun rods come from the datsun 1600 and the datsun 180b and the lengths are L16- 133mm L18- 130mm ,Im using the 130mm rods in a 1600 with a datsun L18 crank although datsun rods can be used with ford crank 11 13 or 1600. I had the small end machined out and fitted ford conrod bushes , and the big end resized for ford bearings. The log rods from burton are 132.8 which would work, you still will probably have to alter the compression height or deck height of the block to get zero deck. There is plenty of meat in these pistons to machine out and a lighter piston is a good thing.

[ebenech]

Hello the datsun rods come from the datsun 1600 and the datsun 180b and the lengths are L16- 133mm L18- 130mm ,Im using the 130mm rods in a 1600 with a datsun L18 crank although datsun rods can be used with ford crank 11 13 or 1600. I had the small end machined out and fitted ford conrod bushes , and the big end resized for ford bearings. The log rods from burton are 132.8 which would work, you still will probably have to alter the compression height or deck height of the block to get zero deck. There is plenty of meat in these pistons to machine out and a lighter piston is a good thing.

Hi revnrich, thanks alot for your kind advise, it's very usefull, and now I'm obtaining the info I wanted to: the ones from people that have experimented doing this to their engines, and are using them satisfactorily. It makes my think in keep going whith my project.

But still revnrich, I have this doubt, is it worth while of doing this to my "big bore" engine that is doing very well ? Will I get any gains and which would they be ?

I'll appreciate to have your comments in this fact too.

Thanks in advance for your fine cooperation, and look forward to your kind news.

Cheers,

Eduardo

[revnrich]

Hi Eduardo its probably not worth pulling apart your good engine. If you were building an engine from scratch I would reccommend using a longer rod, either burtons or datsun and modifyed piston. Its seems as though your engine is pretty good and you probably would'nt notice the difference. If you are using the 32/36 the manifolding is pretty average and you would definatly improve things with side drafts or bike carbs. What cam are you using? A fast road cam and decent carbs will make a good improvement.
The limiting factor of your engine will be manifolding and the factory crank is only good for 6750 rpm. I have revved them to 7500 but woulnt make a habit of it, that was fully balanced aswell. Balancing is some of the best spent money on a engine.
If money wasnt an issue Id build a kent engine with 85mm bore, Datsun crank and rods, 4kg billit flywheel, forged pistons, cnc big valve alloy head from cncheadsuk, 1.69:1 roller rockers from burtons, custom intake manifold with injectors and throttle bodies, ford edis crank trigger ignition with coil packs, megasquirt computer to run them both. And a lot of attention to detail in all areas!
One day.....I hope

Richard

[ebenech]

Hi Richard, many thanks for your reply with extra detailed info about my query. It was just what I needed to leave my 1700 "big bore" quiet. My cam set is a Piper 285 that goes very well. Anyway, I have a couple of 1600 xflows sleeping overthere, and maybe I'll do something wiht one of them. Do you mind if I come back to you on the near future about his iinteresting point ?

In the meatime, many thanks again for your valuable help.

Cheers,

Eduardo

[revnrich]

Hey Eduardo always happy to help if I can, good to talk with people with the same interests.

Thanks Richard