4.7L
Thread Starter
Racer
Joined: Jul 2004
Posts: 475
Likes: 0
From: Princeton, NJ, USA
4.7L
Hey.
Some probably know that I want to do a block swap. So, I found this engine on the EBay:
http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT
I have a 4.5 CIS engine installed(M28.03).
So, I have 2 questions:
1) Is a 4.7L engine an intereference engine?
2)Will I be able to install all the components from the engine I have now on this block(I want to use my heads, and don't want to do an engine swap, just the block).
Thanks a lot,
Klim
Some probably know that I want to do a block swap. So, I found this engine on the EBay:
http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT
I have a 4.5 CIS engine installed(M28.03).
So, I have 2 questions:
1) Is a 4.7L engine an intereference engine?
2)Will I be able to install all the components from the engine I have now on this block(I want to use my heads, and don't want to do an engine swap, just the block).
Thanks a lot,
Klim
Rennlist Member
Joined: Dec 2002
Posts: 5,283
Likes: 52
From: Australia
1. Religious question - some say NO, some say maybe, some say 10.4:1 CR Yes, some say 10:1 CR yes. I personally have seen a 10.4:1 CR Euro which broke off LHS cam nose, with bent valves on that head. Pretty sure that US lower CR 4.7 are not interference, but dont quote me.
2. Based on no experience, I think you are safe to move all your 4.5 manifolds to this 4.7. IIRC the only move NOT safe is 2V heads to 5.0L block, as valves will hit pistons unless they (pistons) are relieved to clear.
jp 83 Euro S AT 49k, 10:1 CR...
2. Based on no experience, I think you are safe to move all your 4.5 manifolds to this 4.7. IIRC the only move NOT safe is 2V heads to 5.0L block, as valves will hit pistons unless they (pistons) are relieved to clear.
jp 83 Euro S AT 49k, 10:1 CR...
Rennlist Member
Joined: Feb 2003
Posts: 29,828
Likes: 218
From: saratoga, ca
good points. If we are talking 4.7US, no valve problem with the valves, and the heads and valves are the same for 79s and US 4.7s.. all your stuff will bolt right up.
the euro is the issue with the heads on the US 4.7. this is due to the euro heads having 45mm and 40mm intake and exhaust valves, while the US only has 43mm and 38mm valve diameters. the problem is that the pistons on the US only have 38.5 and 43.5 mm cut outs and you can see that this could be an issue. Anyway, thats just with the euro 4.7 "S" heads and the US bottom end off a 4.7.
One thing i did do was the euro 82 cams on a US 4.7 and the valves didnt hit due to the greater lift and duration. however, i still wonder if the more radical euro 85 cams would be a problem.
the valve cuts on the pistons of a euro 82 are pretty deep., and not so deep on a US 4.7. ironically, with the better cam, the euro 85 pistons have more shallow valve cuts upping the CR to 10.5:1, but certainly more of a chance for valves to hit if you break a timing belt.
MK
the euro is the issue with the heads on the US 4.7. this is due to the euro heads having 45mm and 40mm intake and exhaust valves, while the US only has 43mm and 38mm valve diameters. the problem is that the pistons on the US only have 38.5 and 43.5 mm cut outs and you can see that this could be an issue. Anyway, thats just with the euro 4.7 "S" heads and the US bottom end off a 4.7.
One thing i did do was the euro 82 cams on a US 4.7 and the valves didnt hit due to the greater lift and duration. however, i still wonder if the more radical euro 85 cams would be a problem.
the valve cuts on the pistons of a euro 82 are pretty deep., and not so deep on a US 4.7. ironically, with the better cam, the euro 85 pistons have more shallow valve cuts upping the CR to 10.5:1, but certainly more of a chance for valves to hit if you break a timing belt.
MK