DukeD Mike Duncan Olive Branch, MS (5 posts) Registered: 09/30/2015 08:48PM Main British Car: 73 MGB, 77 MGB V8 Ford 302 |
302 conversion aluminum head upgrade advice
I had planned on running my stock 302 with the Edelbrock Performer intake and 600 cfm Holley for a
while before making any upgrades but I came across one of those "too good to pass up deals". I found a set of AFR 185 heads, 60cc chambers, Crane roller rockers, Bullet hydraulic roller cam and lifters, pushrods, and an Edelbrock RPM intake. And, everything is ligit as is the price. The guy is upgrading his 347. The parts have about 2500 miles on them. I understand the 185 vs 165 issues with the lift and piston clearance. I know some people are fly cutting the pistons and some have suggested a thicker head gasket, which I am not fond of. I was thinking of using the stock cam since I would have to tear down the engine to replace the cam bearings. I was planning on eventually rebuilding the engine later when the budget gets better. I really don't want to put in another cam without changing the bearings. I will do the clay/playdough test to insure piston to valve clearance. I think the RPM is about an inch taller than the Performer so if it doesn't fit under the bonnet I will stay with the Performer. So I'm looking for some words of wisdom. I have always trusted the advice and knowledge from you guys. Any advice will be greatly appreciated. Cam specs. - Duration @.050 Int 234 Exh 240 Lift-Int .565 Exh .565 |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: 302 conversion aluminum head upgrade advice
I'd see if you can just get the heads. The cam is too much for the street. You would be much happier with the duration around 220@ .050 and lift around . 500. Plenty of performance and no valve clearance issues. The RPM is okay but the height and more top end performance isn't really necessary.
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Dan Jones Dan Jones St. Louis, Missouri (280 posts) Registered: 07/21/2008 03:32PM Main British Car: 1980 Triumph TR8 3.5L Rover V8 |
Re: 302 conversion aluminum head upgrade advice
> I was thinking of using the stock cam since I would have to tear down the engine to replace the cam bearings
Do you know the cam bearings need replacing? When I pulled the 5.0L HO engine for inspection at 163,000 miles, the cam bearings were still on the tight side of spec. That engine has 240,000 miles now with those same cam bearings and still holds great oil pressure. > Cam specs. - Duration @.050 Int 234 Exh 240 > Lift-Int .565 Exh .565 What's the lobe separation angle on that cam? What cc's are the heads? Is your short block an HO or does it have cast pistons? That's a lot of duration for 9:1 or less compression ratio. > Plenty of performance and no valve clearance issues. The AFR 185 heads have 2.02" diameter valves which can have piston-to-valve issues with the stock pistons. Dan Jones |
DukeD Mike Duncan Olive Branch, MS (5 posts) Registered: 09/30/2015 08:48PM Main British Car: 73 MGB, 77 MGB V8 Ford 302 |
Re: 302 conversion aluminum head upgrade advice
Dan,
The lobe separation is 108 according to the seller. The AFR 185 chamber is 60cc. I saw the engine running before I bought it. Pressure was good and everything seemed tight. It had 60,000 miles on a rebuild so I'm not sure the total miles. The guy says all was original. Yes I'm concerned about the valve clearance. I may purchase everything and hold on to it for a future rebuild. It's more power than I'll ever need in the little B but "just because". Now I'll have to work on building the Dana 44 rear end. I was holding off on that too. Boys and their toys. I just hope I can get everything back together and running before father time catches up with me. Jim, I just got your post on the other forum. Thanks |