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> Bigger valves in 1.8 heads?
Korijo
post Jul 16 2005, 06:23 PM
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can you use a 2L exhaust valve in a 1.8L head? [after machining, of corse (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) ]

i was thinking [ (IMG:http://www.914world.com/bbs2/html/emoticons/smoke.gif) ] of only bumping the exhaust up to 36mm, and leaving the intakes at 41mm? common practice? weird?

i have a set of loaded, rebuilt 2L heads; but i want to use the Solex PII 40's Joe Sharp gave me*, so i'm gettin' some 1.8L heads...



* [thanks again joe (IMG:http://www.914world.com/bbs2/html/emoticons/pray.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/clap.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/boldblue.gif) ]
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Jake Raby
post Jul 16 2005, 09:48 PM
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1.8 heads don't have the spark plug cracking issues of the 2.0 because of plug location. We flycut 1.8 heads down almost to the sparkplug on F prod engines and no crack issues..

Going to the 36mm exhaust without upping the intake valve will imbalance the head quite a bit..

42x36 valves(stock 2.0 size) can be used in a 1.8 head and still be supported by stock ports. Porting will help, but is not necessary..

Spark plug relocation has given us 8% more power+ in every instance that we have tested it..
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Posts in this topic
Korijo   Bigger valves in 1.8 heads?   Jul 16 2005, 06:23 PM
qa1142   Valves are not the problem. The porting angles and...   Jul 16 2005, 06:28 PM
anthony   You can also have the 1.8 spark plug holes welded ...   Jul 16 2005, 07:55 PM
Korijo     Jul 16 2005, 08:39 PM
tat2dphreak   <...   Jul 16 2005, 09:08 PM
Korijo   i can use 2L valves in a 1.8 head WITHOUT changing...   Jul 17 2005, 01:49 PM
gregrobbins   Why don't you use the 2.0L heads? Carb manifol...   Jul 17 2005, 03:57 PM
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