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Airwreckc
Eric Cumming
RTP, North Carolina
(80 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: August 26, 2022 01:52PM

Jim,

I don't *need* to heat treat them--however, I've recently read that heat treating can improve the strength of the head material, so that retorqueing as often is not required, as well as where the studs are located for the valve train. I've heard that it's a nice to have as the 300 heads have pretty soft aluminum.


MGBV8
Carl Floyd
Kingsport, TN
(4284 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: August 26, 2022 03:34PM

Quote:
If someone were to find and post Dan's TA flow bench results that should be illuminating.

Here ya go:

[forum.britishv8.org]


Airwreckc
Eric Cumming
RTP, North Carolina
(80 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: August 27, 2022 09:49AM

Thanks Carl,

Those TA flow numbers are very helpful (I've pasted them below for reference):

Dan Jones' report of porting TA cylinder heads

Stock 4.6 heads with 1.575" intake valves,
vs. ported 300 heads with 1.775" intake valves
vs. out-of-the-box TA heads with 1.94" intake valves
vs ported TA heads with 1.94" intake valves
vs ported TA heads with back-cut 1.94" intake valves

'back-cut' means the valves were given a 30 degree back-cut.


Intake

Lift 4.6 B 300 POrig TA Ported back-cut
dia. 1.575"1.775"1.94"1.94"1.94"
0.100 60.2 66 67.7 76.8 78.3
0.200 105.4 129 105.4 120.4 129.4
0.300 132.4 174 143.0 173.1 185.1
0.350 135.5 187 164.0 198.7 206.2
0.400 135.5 191 185.1 224.2 225.8
0.500 n/a 196 220.9 255.9 251.3
0.600 n/a 200 225.8 (n/a) 252.8




Exhaust

Lift 4.6 B 300 POriginal Ported
dia. 1.35" 1.5" 1.6" 1.6"
0.100 57.4 47 47.9 63.8
0.200 92.5 104 70.2 108.5
0.300 103.7 130 102.1 146.7
0.350 106.9 139 114.9 n/a
0.400 106.9 146 126.0 177.0
0.500 n/a 152 137.2 189.8
0.600 n/a 153 140.4 199.4


What's interesting is how well the ported 300 heads did. I'm wondering if anyone knows what a similar valve job (with the larger valves) and that porting might cost someone (assuming I could actually find someone who knows what they are doing)--I'm asking as I already own a pair of good 300 heads. And how much horsepower is reasonable to get out of those flow numbers without a crazy cam? Just curious if anyone has any thoughts. Trying to compare to the TA heads, which I found out are soon to be back in stock.




I edited in Paul Menten's excellent table version of the flow numbers. -Carl



Edited 2 time(s). Last edit at 08/29/2022 08:43PM by MGBV8.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: August 28, 2022 08:30AM

What stands out to me is the flow of the unported TA exhaust. With a 1.6" valve, something there seems a bit off. I'd love to know why but I suppose that's something Dan would have to answer.

Jim


Airwreckc
Eric Cumming
RTP, North Carolina
(80 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: August 29, 2022 01:10PM

Jim,

I noticed that, too. I was surprised that the 300 head (ported) would be better than the unported TA head on the exhaust side.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: August 29, 2022 07:29PM

Looking at the ports and the valve sizes I really don't see how it can be. I'll try to take some photos and post them tomorrow or the next day.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(4284 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: August 29, 2022 08:37PM

As Dan Jones explains farther down the page:

"Those Buick 300 heads were fitted with larger seats and Ferrea 6000 series Buick V6 Stage 1 stainless steel valves (1.775" intake and 1.5" exhaust). Intakes have a 10 degree "Super Flo" head shape while the exhausts are 29 degree tulips. The heads were hand ported by Jon Carls of JDC Engineering in Minonk, IL. I supplied Jon with a corroded Buick 300 head which he used to determine the casting material thickness limits. Given that the unported heads flowed 154/116 CFM @ 0.600" lift, he did a very good job. The exhaust to intake flow ratio and low to mid-lift numbers are quite good."



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: August 30, 2022 09:13AM

So apples to apples we're comparing 116 to 140 which is a quite significant improvement.
I think we may still need the comparison for OEM 300 heads to OEM 4.6 heads.

Jim


Robrover
Rob Thornton
Adelaide, Australia
(20 posts)

Registered:
10/01/2009 11:52PM

Main British Car:
1978 Rover SD1 4.6

Re: TA Rover Heads
Posted by: Robrover
Date: September 09, 2022 11:20PM

The Buick 300 heads on my 4.6 SD1 were originally modified on a flow bench by Holden/Ford V8 race head guru Eddy Woods at the Head Stud Development Co in Melbourne, and they were originally destined for a 5.0 litre Leyland P76 motor that went into an extensively lightened LC Holden Torana drag car.

They were later welded and re-flowed locally by Air Flow Developments and now flow 193 cfm at 550 thou (1.75 inlet). Which was quoted to support 405hp (bare). Standard P76 was about 132 cfm at the same lift (P76 heads were the same as the early Rover P6B heads). I think the later post 1976 SD1 Rover heads flowed about 148cfm at the same lift, with Stage 4 Rover heads around 181. Stock 300 heads flow 153 cfm at 550.

I believe Merlin F85 heads can be maxed out to flow about 185 cfm.

I read somewhere that Lanocha in the US flowed over 200cfm from Buick 300 aluminium heads which was sufficient to support 425 hp on a maximum-effort, high-compression, normally aspirated 5.0 litre TR8, and thatís using a single-four-barrel Daemon Racing carb on a Willpower open plenum inlet manifold, not efi.

300 heads are softer than Rover heads being cast in 3000 aluminium. They can suffer from head bolt bosses spreading when torquing down, as well as loosening head bolts and rocker studs pulling out. Heat treating or re-tempering them to T-6 is claimed to improve matters, though I haven't done this myself yet.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: September 10, 2022 08:40AM

I can confirm that the 215 heads were soft and would expect the 300 alloy heads to be the same. Thick washers on the head bolts are a necessity as thin ones can cone and allow the bosses to deform.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(4284 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: September 12, 2022 10:02AM

Rob, those number would be great for comparison, if it was known at what pressure they were tested.
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