Hi. Just returned from our 3 week road trip with engine backfiring and no power on hills. Got me home at least and put in to garage for rectification. Pressure check revealed no 4 with nil compression. Engine has come out and mechanic has just informed me that the cylinder head is cracked. Trying to source new head and finding difficulty with which supplier to use. JK don't have stock but Heritage shows stock at over £300,00 +. Also need new clutch as oil leak found to have contaminated the original which is a 210 unit but the spec says it should be a 215 unit. Mechanic has said that he will remove the other head just to make sure its ok. Need help from you experts as to where to go for a good quality head or can the crack be repaired?, Also what else should else should I do or change while engine is out. Assuming change seals to stop leaks. Your help will be greatly appreciated.
Cracked Cylinder heads on Type 4 engines ... Its why the Americans fit cylinder head temperature gauges to their Type 4 engines, rather than oil temperature gauges usually fitted to a Type 1 engine . And despite the fact that Type 4 engines are more generally durable the cylinder heads are the weakness. And because fewer of these engines were made and perhaps because they do not break as often as Type 1 engines the spares are rarer and more expensive. It will be possible to have it repaired with lots of grinding welding and machining.. but it will cost. And leave a question mark over whether it was done right. Buy a new one. But keep the old one for when repairing gets cheaper than buying.
You'll have to replace both heads, as the new 1800 heads run T25 valve sizes... so old head is 41x34, new heads are 39.3x34... So replacing one head would lead to an unbalanced engine... Second hand heads are a real gamble... I've bought a few 1800 heads, and have binned them as they were cracked...
Many thanks. Looks like the cost keeps rising. Will replace both as you suggest. Any idea of the best place to go for sourcing good quality heads or are heritage ones ok?
@zed is sorted for 1800 heads now @shahaviation The heads heritage sell are made by AMC... they are the only aftermarket manufacturer of type 4 cylinder heads!! Speak to heritage nicely, and they might do you a little bit of discount on them
Coolair have virtually no margin on them... hence no discount... I get pretty good discount being trade, but every engine part has a different discount on it... it's all in the margins as to what I get!!
if you swap the good one as well and its good id buy that from you. At least youd recoup some cash back! However, get the valves measured. You might be lucky and its previously had them swapped out
Many thanks guys. I'll get the valves measured and then speak to heritage nicelike. If I swap both I will let you know if the other head is good to sell. In the meantime I'll get the gasket set and crankshaft seals and clutch from Get as they have the usual 35% off this weekend.
Hi. Finally got pictures from the mechanic and head cracked as shown. The part number 021.101.371s S appears to be the original units and waiting for them to take the other head off to see the condition and also confirm the part number. Engine is AW code so ita a 1800 1973/74 . Looks like two new heads with small heritage discount bringing price down to £275.00 each.
Here is the link to dropbox for the pics. https://www.dropbox.com/sh/h5n2k5dhtklppfb/AACFD3v-CAjVL6vU4NUVFNtea?dl=0