increasing compression in a 1.8 carb engine

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roan adriaanse
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increasing compression in a 1.8 carb engine

Post by roan adriaanse »

hey i own a 1.3 golf and has decided recently to buy a 1.8 carb engine ,i just whant to know what can i do to increase the compresion ratio and i also whant to know if by putting a 1.8 fuel injected model's crank in the 1.8 carb engine if that whould do the job sorry if im asking dumb questions but whould realy appreciate the help
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VWicked
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Re: increasing compression in a 1.8 carb engine

Post by VWicked »

Why do you want to increase compression?

Anyway crank won't do anything, you can skim the head if you really must.
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roan adriaanse
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Re: increasing compression in a 1.8 carb engine

Post by roan adriaanse »

I was thinking of flowing the head putting in a cam and lightning and balancing the crank and flywheel and jetting the original carb and a k&n airfiter with branches but still what to do somthing more and the only thing I chould thing of was compression .so to skim the head is the only way?
JonathanRS
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Re: increasing compression in a 1.8 carb engine

Post by JonathanRS »

hi
I run a 1.8 carb model in an origional jetta 2 clx - go goes well with 390k on the clock - motor unopened. either you go the full fuel injection and managment route (then you have the wrong motor)
or freshen up your 1.8 and leave it pretty stock. Nothing wrong with a nice balanced and smooth running motor. carb is relatively cheap if you need to replace it. dont waste your time on weber conversions.
I run an ave of 8.9 l/100 everyday driving so fairly economical. On a road car i would not worry about lightening the crank. balance crank and clutch together though. blance pistons and rods. take the time to ensure all are in specification or are the same - mild flow on head or branch wont hurt - more of a clean up and matching of ports to manifolds. easy enough to do without major expense
good luck. Dont try and make a race car out of your road car -1.3 to 1.8 you will enjoy the new power and torque.
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Re: increasing compression in a 1.8 carb engine

Post by Scooby GP »

Put the 1300 head on the 1800 block.
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HendrikCTI
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Re: increasing compression in a 1.8 carb engine

Post by HendrikCTI »

Be careful when increasing compression on a VW motor. VW engines run very hot and with our crappy fuel it is easy to get preignition.
Know someone who skimmed his Polo's cylinder head to the max. Car pinged and he could only get it to stop by running caltex fuel.
He is a mechanic.
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roan adriaanse
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Re: increasing compression in a 1.8 carb engine

Post by roan adriaanse »

thanx jonathan i got the engines this week got them for a resanoble price R2500 engine codes jv and the other 2 hv the hv has the mexican heads on them and the jv the german on , the engines look in good shape opened them up and asked my mechanic vriend to come take a look the pistons have no numbers on them according to him that means its the original pistons or put it like this the engines hasent been rebored yet. but i dont want to go crazy with the compression thing just want to increase it a little just that little exstra but what i want to know now what is the beter 1.8 engine of the 2 difrent engine codes hv and jv
JonathanRS
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Re: increasing compression in a 1.8 carb engine

Post by JonathanRS »

Hi

Both engines are from the same era 1986 to 1988. the JV seemsto come out of a passat and the HV was stock in golf jetta. passat would have been longitudinal mount - make sure it has correct sump and dipstick or you can get incorrect reading and over or underfill oil. i dont think there is much difference in them - both should have forged 1.8 crank. head is the only key - i am guessing the german one may be a better one - get an engineering shop to compare.
you got them cheap enough - good luck
roan adriaanse
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Re: increasing compression in a 1.8 carb engine

Post by roan adriaanse »

aaah oky thanx wil keep that in mind was thinking of taking the engines to the engeneering to take a look at the engins gonna save up a little more and get the engine up to spec with all the little things like the crank and flywheel thinking of reboring the engine to a bigger piston size and later flowing the head i live in mosselbay btw hoping to have the engine in by the end of next month or the month after that but the one crank has more lobes than the other one the one has 8 and the other 4 ?
Ameermk18v
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Re: increasing compression in a 1.8 carb engine

Post by Ameermk18v »

look so i also had a 1.3 crab when i bought my car and then it ran a bearing so i only had enough money for a 1.8 carb when i wanted a 2L so i’ve been running my 1.8 8v with dellorto side drafts and i had webbers on both 45mm depends on what you want


so in my opinion go the old school way and do side drafts and have then tuned by Rowland Motor drive not sure if u from where i am but ya and i still had my 4 speed gearbox on and a lightened flywheel stock head stock block and i ran a few cars a hell of a night for a 1.8 8v carb with steelie wheels on 😂

at the moment my engine is opened i ran a bearing on the 1.8 so i’m still deciding if i should put 83mm pistons on from a caravelle van but i’m still busy doing the head like a port and polish the head , put in a 288 cam in and only do the head really for now i think you should get side drafts and do your head you’ll thank me later and i hope you get to see this


ameer samsodien
0788177136
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