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View Full Version : Cylinder head interchangeability/advantages primer?



Ashyukun
11-13-2017, 12:00 PM
Since my '82 Rampage with its '89 LeBaron 2.5 TII is a GRM Challenge car- and will be remaining so until at least next year's competition- I'm always on the lookout for relatively inexpensive upgrades and even just replacement parts. As such, I figured it would be good to know what heads I should be looking out for to be able to grab as potential replacements/ones I can work on porting to swap in down the line. Is there a good primer/guide on the different heads between the 2.2/2.5 engines, and/or if there are other engines that the heads will work off of (since the older cars are getting more difficult to find in junkyards...)? Thanks!

Dr. Johny Dodge
11-13-2017, 12:22 PM
86-93 pretty much use the same head - so called swirl

86 and 7 would have slots in the cam bearing caps that allow oil to get to the cam followers - the later roller cam heads would lack those slots

turbo motors got the needed stainless ex valves
swirl heads use a slightly longer valve - so they don't interchange between early head and late head

some discussion has been had in the past as to the "tune" being difficult on a 2.5 with an earlier head - 82-5

I think personally this may be due to the much larger dish used in the 2.5 piston top vs the small dish in the earlier motors

I have a feeling the large dish doesn't work quite right with the earlier combustion chambers

masterjr33
11-13-2017, 12:42 PM
http://www.thedodgegarage.com/turbo_heads.html

Ashyukun
11-13-2017, 03:38 PM
OK, that's a lot of useful info, thanks!

Sounds like, summarizing a bit, that basically any 86-or-later head will work, but I need to make sure it has the turbo valves when it goes into the engine. Which means by and large that I'll probably need to limit myself to 86+ turbo heads since having the valves converted over isn't going to be in the budget.

cordes
11-13-2017, 09:38 PM
I'm not sure what your budget is like, but the turbo exhaust valves are pretty cheap these days. You can pretty easily identify them because they are significantly less magnetic than the TBI valves.


https://www.youtube.com/watch?v=i2mr85vZEt8

Ashyukun
11-14-2017, 12:16 AM
The cost of the valves themselves wouldn’t likely be the problem, it would be having the cylinder head shop machine the heads.

cordes
11-21-2017, 09:43 PM
The valves drop right in.

iangoround
11-27-2017, 03:34 PM
Last head I had done only ran me about $300 for hot tank, pressure check, decking, valves and seats cut, new guides, seals, springs installed to height, etc. Not really that bad considering the amount of work that went in to it.

turbovanman²
12-30-2017, 11:47 PM
I'd go with the swirl head. The casting number is around the thermostat area and ends in 782. Any other head will be the old school G head, and that debate would start a war, lol.