Tom Clerkin Posted May 9, 2018 Share Posted May 9, 2018 Hi folks,I wanted to retain my original 1.6 engine block but looking to increase performance, I have a good set of 2.0 pistons/conrods and am about to send block for overhaul. Does anyone know if GM simply continued to bore out the original block to increase cc or were blocks cast differently to compensate for increasing bore size? Basically I'm looking to have 5mm taken out of the bore wall, is there enough metal left to take that? I cant find out if anyone has done it.I realise one option is to fit a 2.0 engine but I really want to try and retain the cars originality. Its a Manta A and I would really like to retain engine so numbers match but give it more get up and go.? Also I plan on fitting side draught carbs/ manifolds etc as these can always be taken off again and put back to look stock at any point. Any help greatly appreciated. Tom Quote Link to comment Share on other sites More sharing options...
Paul Barrett Posted May 9, 2018 Share Posted May 9, 2018 Just re stamp the 2ltr block? Quote Link to comment Share on other sites More sharing options...
moodoo Posted May 9, 2018 Share Posted May 9, 2018 I seem to remember reading something that the 1.9 and the 1.6 were the same block, but the 2.0 was a different casting. You can certainly take a 1.9 out to 95mm bore, so if it is the same as the 1.6, it should work, but it seems like a lot of metal to remove! Bravery... Quote Link to comment Share on other sites More sharing options...
Tom Clerkin Posted May 10, 2018 Author Share Posted May 10, 2018 19 hours ago, moodoo said: I seem to remember reading something that the 1.9 and the 1.6 were the same block, but the 2.0 was a different casting. You can certainly take a 1.9 out to 95mm bore, so if it is the same as the 1.6, it should work, but it seems like a lot of metal to remove! Bravery... Ha yeah! I'll see how much metal is between the bores when I take the head off........ anything less than 20mm doesnt' leave much margin for error. Quote Link to comment Share on other sites More sharing options...
Julian Posted May 10, 2018 Share Posted May 10, 2018 36 minutes ago, Tom Clerkin said: Ha yeah! I'll see how much metal is between the bores when I take the head off........ anything less than 20mm doesnt' leave much margin for error. If you did that wouldn't you have to have larger exhaust valves? Quote Link to comment Share on other sites More sharing options...
Tom Clerkin Posted May 10, 2018 Author Share Posted May 10, 2018 4 hours ago, Julian said: If you did that wouldn't you have to have larger exhaust valves? Yes I'm planning on fitting a 2.0 head and piper cam Quote Link to comment Share on other sites More sharing options...
®evo03 Posted May 11, 2018 Share Posted May 11, 2018 Why not build a engine, and keep you 1.6 original, you cant go back, once bored, and if something goes wrong, you have destroyed what you want to retain, the engine number, there is no need to declare an engine increase in a historic car with dvla. If you build a 2.4 or 2.2 or or 2.0, someone said a 1.9 is quicker with carbs than a 2.0, cant remember how, stroke maybe! Also do some cih research, 2.4 turbo could be fastest, or complete oldschool mods, increased 2.2 exh valves, 45 carbs. Cams etc. Here is a supplier, https://www.risse-motorsport.de/product_info.php/info/p2128_Complete-engine-CIH-2-0-liter-racing.html/XTCsid/1ll3up2pe6okf290g99rr9kt34 Quote Link to comment Share on other sites More sharing options...
611 Posted May 11, 2018 Share Posted May 11, 2018 According to this site the 1.6 pistons are 85mm https://www.oldtimer-motorenteile.com/product_info.php?info=p8204_pistons-opel-manta-a-1600s--70---75.html and i think the 2L are 95mm?, so that would be quite a bit to bore out. I might be wrong. Best option in my opinion is get the 1.9, have it bored to 2L and get a nice big valve 2L head with a nice cam. Nice and easy to get done, not that expensive and its nice and quick. 2.4 is way too much hassle and a lot more expensive compared to the 1.9 option. Andy Quote Link to comment Share on other sites More sharing options...
rutts Posted May 12, 2018 Share Posted May 12, 2018 It' not the distance between bores its the bore to water jacket to measure. As above just build a good 2.0. You can use your 1.6 crank in a 2.0 its much better balanced. Valves are on eBay now to make a bigger valve head. Quote Link to comment Share on other sites More sharing options...
Tom Clerkin Posted May 12, 2018 Author Share Posted May 12, 2018 On 5/11/2018 at 18:43, ®evo03 said: Why not build a engine, and keep you 1.6 original, you cant go back, once bored, and if something goes wrong, you have destroyed what you want to retain, the engine number, there is no need to declare an engine increase in a historic car with dvla. If you build a 2.4 or 2.2 or or 2.0, someone said a 1.9 is quicker with carbs than a 2.0, cant remember how, stroke maybe! Also do some cih research, 2.4 turbo could be fastest, or complete oldschool mods, increased 2.2 exh valves, 45 carbs. Cams etc. Here is a supplier, https://www.risse-motorsport.de/product_info.php/info/p2128_Complete-engine-CIH-2-0-liter-racing.html/XTCsid/1ll3up2pe6okf290g99rr9kt34 Well I've got the head off and its a no go, there's no way there will be enough metal left. So...... I'm in absolute agreement with you, so its going to be a search for another motor., dont want to go the stroker route, so its 1.9 or 2.0, play around with heads cams etc. Thanks for the info 5 hours ago, rutts said: It' not the distance between bores its the bore to water jacket to measure. As above just build a good 2.0. You can use your 1.6 crank in a 2.0 its much better balanced. Valves are on eBay now to make a bigger valve head. Yeah thats what I meant, Took head off today and its exactly how you say, I was optimistic when I took the gasket off but feeling inside the water jacket it narrows, so there isnt enough thickness. So its keep the original engine to one side and find a 2.0 or 1.9 to play with now. Thanks for the info Quote Link to comment Share on other sites More sharing options...
611 Posted May 12, 2018 Share Posted May 12, 2018 Just from my experience, if your planning on running twin carbs spend the money on a good head and cam. Big valves and set up for maximum flow as not being a cross flow its hard to get a good balance right across the rev range. My best setup was a big valve head on a 2.0L bottom end with twin 45's and that was a nice setup. Andy Quote Link to comment Share on other sites More sharing options...
Tom Clerkin Posted May 13, 2018 Author Share Posted May 13, 2018 (edited) On 5/11/2018 at 23:00, 611 said: According to this site the 1.6 pistons are 85mm https://www.oldtimer-motorenteile.com/product_info.php?info=p8204_pistons-opel-manta-a-1600s--70---75.html and i think the 2L are 95mm?, so that would be quite a bit to bore out. I might be wrong. Best option in my opinion is get the 1.9, have it bored to 2L and get a nice big valve 2L head with a nice cam. Nice and easy to get done, not that expensive and its nice and quick. 2.4 is way too much hassle and a lot more expensive compared to the 1.9 option. Andy I completely agree Andy, after taking the head off and checking, theres no way its a viable option. so I'm on the hunt for a 1.9 or 2.0 now 12 hours ago, 611 said: Just from my experience, if your planning on running twin carbs spend the money on a good head and cam. Big valves and set up for maximum flow as not being a cross flow its hard to get a good balance right across the rev range. My best setup was a big valve head on a 2.0L bottom end with twin 45's and that was a nice setup. Andy Thanks Andy, that sounds like the best option, the bore out isnt viable. So I'm on the look out for all the above .... Cheers Edited May 13, 2018 by Tom Clerkin Replying to wrong person Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.